Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
  • C07K14/001—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof by chemical synthesis
  • C07K14/003—Peptide-nucleic acids (PNAs)
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K7/00—Peptides having 5 to 20 amino acids in a fully defined sequence; Derivatives thereof
  • C07K7/02—Linear peptides containing at least one abnormal peptide link
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
  • B01J2219/00583—Features relative to the processes being carried out
  • B01J2219/00592—Split-and-pool, mix-and-divide processes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
  • B01J2219/00718—Type of compounds synthesised
  • B01J2219/0072—Organic compounds
  • B01J2219/00729—Peptide nucleic acids [PNA]

Definitions

• This invention is directed to improved synthetic processes for forming oligomeric peptide nucleic acids and combinatorial libraries of these peptide nucleic acids.
• the invention further includes new peptide nucleic acid chimeric structures.
• the processes of the invention utilize both monomeric and sub-monomeric synthons to form the oligomeric peptide nucleic acids having either random or predefined sequences of monomeric units.
• Each of the monomeric units includes a chemical moiety thereon for binding of the oligomeric structures to proteins, nucleic acids, and other biological targets.
• compounds prepared via the processes of the invention act as inhibitors of enzymes such as phospholipase A 2 and are useful for the treatment of inflammatory diseases including atopic dermatitis and inflammatory bowel disease.
• a technique called SURF (Synthetic Unrandomization of Randomized Fragments) , involves the synthesis of subsets of oligomers containing a known residue at one fixed position and equimolar mixtures of residues at all other positions. For a library of oligomers four residues long containing three monomers (A, B, C) , three subsets would be synthesized (NNAN, NNBN, NNCN, where N represents equal incorporation of each of the three monomers) . Each subset is then screened in a functional assay and the best subset is identified (e.g.
• NNAN NNAN
• a second set of libraries is synthesized and screened, each containing the fixed residue from the previous round, and a second fixed residue (e.g. ANAN, BNAN, CNAN) .
• ANAN e.g. ANAN, BNAN, CNAN
• a unique sequence with activity in the assay can be identified.
• the SURFs technique is described in Ecker, D.J., Vickers, T. A., Hanecak, R., Driver, V. & Anderson, K., Nucleic Acids Res . , 1993, 21 , 1853-1856.
• the SURF method is further described in PCT patent application WO 93/04204, the entire contents of which is herein incorporated by reference.
• Peptide nucleic acids have been demonstrated to be useful surrogates for oligonucleotide in binding to both DNA and RNA nucleic acids (see Egholm et al . , Nature, 1993, 365, 566-568 and reference cited therein and PCT applications WO 92/20702, WO 92/20703 and WO 93/12129) . Additionally peptide nucleic acids have demonstrated the ability to effect strand displacement of double stranded DNA (see Patel, D.J., Nature, 1993, 365, 490-492 and references cited therein) . It is not known to prepare peptide nucleic acid libraries however or to use peptide nucleic acid monomers in combinatorial techniques .
• novel processes for the synthesis of peptide nucleic acid oligomers there are provided novel processes for the synthesis of peptide nucleic acid oligomers.
• chimeric compounds of the peptide nucleic acids and normal amino acids and process for making the same.
• certain novel process for the preparation of libraries of peptide nucleic acid oligomers having random sequences and libraries of peptide nucleic acid oligomers having both random and fixed positions are provided.
• a method of adding further peptide nucleic acid units to an amine terminated peptide nucleic acid oligomer on a solid phase synthesis resin includes treating the amine terminated oligomer on the solid phase synthesis resin with a bifunctional acetyl synthon to react a first reactive site of the bifunctional acetyl synthon with the terminal amine of the oligomer to form a resin bound oligomer having a monofunctional acetyl moiety thereon.
• the method further includes selecting an alkyldiamine synthon having the first of its amino functional groups in the form of a protected amino group and the other of its amino functions groups as a free amine.
• the method further includes treating the resin bound oligomer having the monofunctional acetyl moiety thereon with the alkyldiamine synthon to covalently bond the acetyl moiety and the free amine group of the alkyldiamine synthon forming a resin bound oligomer having an extension thereon where the extension includes a secondary amine and a protected amino group.
• the method further includes treating the oligomer having the extension thereon with an acetylnucleobase synthon to form an amide bond between the acetylnucleobase synthon and the ' secondary amine of the extension forming a new protected amine terminated resin bound peptide nucleic acid oligomer.
• the method further includes deprotecting the protected amino group of the resin bound extended oligomer and repeating further iteration of the method to further extend the oligomer. Upon completion of a product of the desired length, the synthesis is terminated.
• a method of adding further random peptide nucleic acid units to an amine terminated peptide nucleic acid oligomer on a solid phase synthesis resin includes treating the amine terminated oligomer on the solid phase synthesis resin with a bifunctional acetyl synthon to react a first reactive site of the bifunctional acetyl synthon with the terminal amine of the oligomer to form a resin bound peptide nucleic acid oligomer having a monofunctional acetyl moiety thereon.
• the method further includes selecting an alkyldiamine synthon having the first of its amino functional groups in the form of a protected amino group and the other of its amino functions groups as a free amine and treating the resin bound peptide nucleic acid oligomer having the monofunctional acetyl moiety thereon with the alkyldiamine synthon to covalently bond the acetyl moiety and the free amine group of the alkyldiamine synthon forming a resin bound peptide nucleic acid oligomer having an extension thereon where the extension includes a secondary amine and a protected amino group.
• the method further includes selecting a plurality of acetylnucleobase synthons wherein each of the synthons has a nucleobase that differs from the nucleobase of others of the synthons and treating the resin bound peptide nucleic acid oligomer having the extension thereon with the plurality of acetylnucleobase synthons to form an amide bond between an acetylnucleobase synthon and the secondary amine of the extension to extend the peptide nucleic acid oligomer with a new protected amine terminated resin bound peptide nucleic acid unit connected to other preceding peptide nucleic acid units.
• the method further includes deprotecting the protected amino group of the resin bound peptide nucleic acid unit to extend the peptide nucleic acid oligomer and repeating further iteration of the method to further extend the oligomer.
• the synthesis is terminated.
• a preselected nucleobase carrying synthon is used during one of said repetitions in place of the plurality of synthon. When so used, this adds the preselected nucleobase synthon to said oligomer and thus fixes that position in the oligomeric compound.
• a method of adding further random peptide nucleic acid units to an amine terminated peptide nucleic acid oligomer on a solid phase synthesis resin includes treating the amine terminated oligomer on the solid phase synthesis resin with a bifunctional acetyl synthon to react a first reactive site of the bifunctional acetyl synthon with the terminal amine of the oligomer to form a resin bound oligomer having a monofunctional acetyl moiety thereon.
• the method further includes selecting an alkyldiamine synthon having the first of its amino functional groups in the form of a protected amino group and the other of its amino functions groups as a free amine and treating the resin bound oligomer having the monofunctional acetyl moiety thereon with the alkyldiamine synthon to covalently bond the acetyl moiety and the free amine group of the alkyldiamine synthon forming a resin bound oligomer having an extension thereon where the extension includes a secondary amine and a protected amino group.
• the method further includes dividing the resin into portions.
• the method further includes selecting a plurality of acetylnucleobase synthons wherein each of the synthons has a nucleobase that differs from the nucleobase of others of the synthons and treating each of the portions of the resin bound oligomer having the extension thereon with one of the acetylnucleobase synthons to form an amide bond between the acetylnucleobase synthon and the secondary amine of the extension to extend the oligomer by the addition of a new protected amine terminated peptide nucleic acid unit connected to the oligomer.
• the method further includes combining each of the portions of resin together, deprotecting the protected amino group of the resin bound peptide nucleic acid oligomer and repeating further iteration of the method to further extend the oligomer. Upon completion of a product of the desired length, the synthesis is terminated.
• a preselected nucleobase carrying synthon is used during one of said repetitions, after dividing the resin, in place of the plurality of synthon.
• this adds the preselected nucleobase synthon to said oligomer in each of the portions of resin and thus fixes that position in the oligomeric compounds.
• the portions of the resin are not recombined but each is treated separately through further iterations of the method.
• a method of adding peptide nucleic acid units to one of an amine terminated peptide nucleic acid oligomer or an amine terminated amino acid oligomer on a solid phase synthesis resin includes treating the amine terminated oligomer on the solid phase synthesis resin with a bifunctional acetyl synthon to react a first reactive site of the bifunctional acetyl synthon with the terminal amine of the oligomer to form a resin bound oligomer having a monofunctional acetyl moiety thereon.
• the method further includes selecting an alkyldiamine synthon having the first of its amino functional groups in the form of a protected amino group and the other of its amino functions groups as a free amine and treating the resin bound oligomer having the monofunctional acetyl moiety thereon with the alkyldiamine synthon to covalently bond the acetyl moiety and the free amine group of the alkyldiamine synthon forming a resin bound oligomer having an extension thereon where the extension includes a secondary amine and a protected amino group.
• the method further includes treating the oligomer having the extension thereon with an acetylnucleobase synthon to form an amide bond between the acetylnucleobase synthon and the secondary amine of the extension forming a new protected amine terminated resin bound peptide nucleic acid oligomer.
• the method further includes deprotecting the protected amino group of the resin bound extended oligomer and repeating further iteration of the method to further extend the oligomer. Upon completion of a product of the desired length, the synthesis is terminated.
• a method of preparing an oligomeric structure composed of mixed peptide nucleic acid units and amino acid units includes selecting one of an amine terminated peptide nucleic acid structure or an amine terminated amino acid structure on a solid phase synthesis resin of the type wherein the structure has at least one peptide nucleic acid unit or at least one amino acid unit.
• the method further includes treating the amine terminated structure on the solid phase synthesis resin with a bifunctional acetyl synthon to react a first reactive site of the bifunctional acetyl synthon with the terminal amine of the structure to form a resin bound structure having a monofunctional acetyl moiety thereon.
• the method further includes selecting an alkyldiamine synthon having the first of its amino functional groups in the form of a protected amino group and the other of its amino functions groups as a free amine and treating the resin bound structure having the monofunctional acetyl moiety thereon with the alkyldiamine synthon to covalently bond the acetyl moiety and the free amine group of the alkyldiamine synthon forming a resin bound structure having an extension thereon where the extension includes a secondary amine and a protected amino group.
• the method further includes treating the structure having the extension thereon with an acetylnucleobase synthon to form an amide bond between the acetylnucleobase synthon and the secondary amine of the extension forming a new protected amine terminated resin bound peptide nucleic acid structure.
• the method further includes deprotecting the protected amino group of the resin bound extended structure and adding an amino acid monomeric unit to the deprotected amino group of the resin bound extended structure or repeating further iteration of the method to further extend the structure.
• the synthesis is terminated.
• the alkydiamine synthon is a C 2 -C 6 alkyldiamine.
• the most preferred alkyldiamine is ethylenediamine.
• a method of adding further peptide nucleic acid units to an amine terminated peptide nucleic acid oligomer on a solid phase synthesis resin includes treating the amine terminated oligomer on the solid phase synthesis resin with a bifunctional acetyl synthon to react a first functional group of the bifunctional acetyl synthon with the terminal amine of the oligomer to form a resin bound oligomer having a monofunctional acetyl moiety thereon.
• the method further includes selecting an alkyldiamine-acetylnucleobase synthon wherein the first amine group of the synthon is present as a protected amino group and the other amine group of the synthon is incorporated into a secondary amide group with the acetyl ⁇ nucleobase portion of the synthon and treating the resin bound oligomer having the monofunctional acetyl moiety thereon with the alkyldiamine-acetylnucleobase synthon to covalently bond the acetyl moiety and the secondary amide group of the alkyldiamine-acetylnucleobase synthon forming a resin bound extended oligomer having a protected amino group thereon.
• the method further includes deprotecting the protected amino group of the resin bound extended oligomer to form a new amine terminated resin bound oligomer and repeating further iteration of the method to further extend the oligomer. Upon completion of a product of the desired length, the synthesis is terminated.
• a further process of the invention there is provided a method of adding further random peptide nucleic acid units to an amine terminated peptide nucleic acid oligomer on a solid phase synthesis resin.
• the method includes treating the amine terminated oligomer on the solid phase synthesis resin with a bifunctional acetyl synthon to react a first reactive site of the bifunctional acetyl synthon with the terminal amine of the oligomer to form a resin bound peptide nucleic acid oligomer having a monofunctional acetyl moiety thereon.
• the method further includes selecting a plurality of alkyldiamine-acetylnucleobase synthons wherein in each such synthon the nucleobase is different from the nucleobase in others of the plurality of synthons and in each such synthon the first amine group of the synthon is present as a protected amino group and the other amine group of the synthon is incorporated into a secondary amide group with the acetyl ⁇ nucleobase portion of the synthon.
• the method further includes treating the resin bound peptide nucleic acid oligomer having the monofunctional acetyl moiety thereon with the plurality of alkyldiamine-acetylnucleobase synthons to extend the peptide nucleic acid oligomer by the addition of a new protected amine terminated resin bound peptide nucleic acid unit .
• the method further includes deprotecting the protected amino group of the resin bound peptide nucleic acid unit to extend resin bound peptide nucleic acid oligomer and repeating further iteration of the method to further extend the oligomer. Upon completion of a product of the desired length, the synthesis is terminated.
• a preselected nucleobase carrying synthon is used during one of said repetitions in place of the plurality of synthon. When so used, this adds the preselected nucleobase synthon to said oligomer and thus fixes that position in the oligomeric compounds.
• a method of adding further random peptide nucleic acid units to an amine terminated peptide nucleic acid oligomer on a solid phase synthesis resin includes treating the amine terminated oligomer on the solid phase synthesis resin with a bifunctional acetyl synthon to react a first reactive site of the bifunctional acetyl synthon with the terminal amine of the unit to form a resin bound peptide nucleic acid oligomer having a monofunctional acetyl moiety thereon.
• the method further includes selecting a plurality of alkyldiamine-acetylnucleobase synthons wherein in each such synthon the nucleobase is different from the nucleobase in others of the plurality of synthons and in each such synthon the first of the amine group of the synthon is present as a protected amino group and the other amine group of the synthon is incorporated into a secondary amide group with the acetyl- nucleobase portion of the synthon.
• the method further includes dividing the resin into portions and treating each of the portions of the resin bound peptide nucleic acid oligomer having the monofunctional acetyl moiety thereon with one of the plurality of alkyldiamine-acetylnucleobase synthons to extend the peptide nucleic acid oligomer by the addition of a protected amine terminated resin bound peptide nucleic acid unit.
• the method further includes combining each of the portions of resin together and deprotecting the protected amino group of the resin bound peptide nucleic acid unit to extend the peptide nucleic acid oligomer.
• the method further includes repeating further iteration of the method to further extend the oligomer. Upon completion of a product of the desired length, the synthesis is terminated.
• a preselected nucleobase carrying synthon is used during one of said repetitions, after dividing the resin, in place of the plurality of synthon.
• this adds the preselected nucleobase synthon to said oligomer in each of the portions of resin and thus fixes that position in the oligomeric compounds.
• the portions of the resin are not recombined but each is treated separately through further iterations of the method.
• a method of adding peptide nucleic acid units to one of an amine terminated peptide nucleic acid oligomer or an amine terminated amino acid oligomer on a solid phase synthesis resin is provided.
• the method includes treating the amine terminated oligomer on the solid phase synthesis resin with a bifunctional acetyl synthon to react a first functional group of the bifunctional acetyl synthon with the terminal amine of the oligomer to form a resin bound oligomer having a monofunctional acetyl moiety thereon.
• the method further includes selecting an alkyldiamine-acetylnucleobase synthon wherein the first of the amine group of the synthon is present as a protected amino group and the other amine group of the synthon is incorporated into a secondary amide group with the acetylnucleobase portion of the synthon.
• the method further includes treating the resin bound oligomer having the monofunctional acetyl moiety thereon with the alkyldiamine-acetylnucleobase synthon to covalently bond the acetyl moiety and the secondary amide group of the alkyldiamine-acetylnucleobase synthon forming a resin bound extended oligomer having a protected amino group thereon.
• the method further includes deprotecting the protected amino group of the resin bound extended oligomer to form a new amine terminated resin bound oligomer and repeating further iteration of the method to further extend the oligomer. Upon completion of a product of the desired length, the synthesis is terminated.
• a method of preparing an oligomeric structure composed of mixed peptide nucleic acid units and amino acid units includes selecting one of an amine terminated peptide nucleic acid structure or an amine terminated amino acid structure on a solid phase synthesis resin and where the structure has at least one peptide nucleic acid unit or at least one amino acid unit and treating the amine terminated structure on the solid phase synthesis resin with a bifunctional acetyl synthon to react a first functional group of the bifunctional acetyl synthon with the terminal amine of the structure to form a resin bound structure having a monofunctional acetyl moiety thereon.
• the method further includes selecting an alkyldiamine-acetylnucleobase synthon wherein the first amine group of the synthon is present as a protected amino group and the other amine group of the synthon is incorporated into a secondary amide group with the acetyl ⁇ nucleobase portion of the synthon and treating the resin bound structure having the monofunctional acetyl moiety thereon with the alkyldiamine-acetylnucleobase synthon to covalently bond the acetyl moiety and the secondary amide group of the alkyldiamine-acetylnucleobase synthon forming a resin bound extended structure having a protected amino group thereon.
• the method further includes deprotecting the protected amino group of the resin bound extended structure to form a new amine terminated resin bound structure and adding an amino acid monomeric unit to the deprotected amino group of the resin bound extended structure to extend the structure or repeating further iteration of the method to further extend the structure. Upon completion of a product of the desired length, the synthesis is terminated.
• the alkyldiamine portion of the alkydiamine- acetylnucleobase synthon is a C 2 -C 6 alkyldiamine.
• the most preferred alkyldiamine is ethylenediamine.
• the method includes treating the amine terminated oligomer on the solid phase synthesis resin with a 1- (2-carbonylmethylnucleobase) -3-oxo-morpholine synthon to form a resin bound oligomer having a N- [2- (nucleobase) acetyl] -N- (hydroxyethyl)glycyl terminus moiety thereon.
• the method further includes treating the resin bound oligomer have the terminus moiety to convert the terminus moiety to an amine terminated N- [2- (nucleobase) acetyl] -N- (aminoethyl) glycyl terminus moiety thereby extending the oligomer by an amine terminated peptide nucleic acid unit and repeating further iteration of the method to further extend the oligomer.
• the synthesis is terminated.
• a method of adding further random peptide nucleic acid units to an amine terminated peptide nucleic acid oligomer on a solid phase synthesis resin includes selecting a plurality of 1- (2-carbonylmethylnucleobase) -3-oxo-morpholine synthons wherein each of the synthons has a nucleobase that differs from the nucleobase of others of the synthons and treating the amine terminated unit on the solid phase synthesis resin with the plurality of synthons forming resin bound oligomers having N- [2- (nucleobase) acetyl] -N- (hydroxy- ethyDglycyl terminus moieties thereon.
• the method further includes treating the resin bound oligomers have the terminus moieties to convert the terminus moieties to amine terminated N- [2- (nucleobase)acetyl] -N- (aminoethyl)glycyl terminus moieties thereby extending the oligomers by one amine terminated peptide nucleic acid unit and repeating further iteration of the method to further extend the oligomer.
• the synthesis is terminated.
• a preselected nucleobase carrying synthon is used during one of said repetitions in place of the plurality of synthon. When so used, this adds the preselected nucleobase synthon to said oligomer and thus fixes that position in the oligomeric compounds.
• a method of adding further random peptide nucleic acid units to an amine terminated peptide nucleic acid oligomer on a solid phase synthesis resin includes selecting a plurality of 1- (2-carbonylmethylnucleobase) -3-oxo-morpholine synthons wherein each of the synthons has a nucleobase that differs from the nucleobase of others of the synthons.
• the method further includes dividing the resin into portions and treating each of the portions of the amine terminated oligomer on the solid phase synthesis resin with one of the plurality of synthons forming resin bound oligomers having N- [2- (nucleobase)acetyl] -N- (hydroxyethyl)glycyl terminus moiety thereon.
• the method further includes combining all of the portions of resin together, treating the resin bound oligomers having the hydroxy terminus moieties to convert the hydroxy terminus moieties to amine terminatedN- [2- (nucleobase)acetyl] - N- (aminoethyl)glycyl terminus moieties thereby extending the oligomers by one amine terminated peptide nucleic acid unit and repeating further iteration of the method to further extend the oligomer.
• the synthesis is terminated.
• a preselected nucleobase carrying synthon is used during one of said repetitions, after dividing the resin, in place of the plurality of synthon.
• this adds the preselected nucleobase synthon to said oligomer in each of the portions of resin and thus fixes that position in the oligomeric compounds.
• the portions of the resin are not recombined but each is treated separately through further iterations of the method.
• a method of adding peptide nucleic acid units to one of an amine terminated peptide nucleic acid oligomer or an amine terminated amino acid oligomer on a solid phase synthesis resin includes treating the amine terminated oligomer on the solid phase synthesis resin with a 1- (2- carbonylmethylnucleobase) -3-oxo-morpholine synthon forming a resin bound oligomer having a N- [2- (nucleobase)acetyl] -N- (hydroxyethyl)glycyl terminus moiety thereon.
• the method further includes treating the resin bound oligomer have the hydroxy terminus moiety to convert the hydroxy terminus moiety to an amine terminated N- [2- (nucleobase)acetyl] -N- (amino ⁇ ethyl)glycyl terminus moiety and repeating further iteration of the method to further extend the oligomer. Upon completion of a product of the desired length, the synthesis is terminated. In even a further process of the invention there is provided a method of preparing an oligomeric structure composed of mixed peptide nucleic acid units and amino acid units.
• the method includes selecting one of an amine terminated peptide nucleic acid structure or an amine terminated amino acid structure on a solid phase synthesis resin and where the structure has at least one peptide nucleic acid unit or at least one amino acid unit.
• the method further includes treating the amine terminated oligomer on the solid phase synthesis resin with a 1- (2-carbonylmethylnucleobase) -3-oxo- morpholine synthon forming a resin bound oligomer having a N- [2- (nucleobase) acetyl] -N- (hydroxyethyl) glycyl terminus moiety thereon.
• the method further includes treating the resin bound oligomer have the terminus moiety to convert the terminus moiety to an amine terminated N- [2- (nucleobase) acetyl] -N- (aminoethyl)glycyl terminus moiety.
• the method further includes effecting one of adding an amino acid monomeric unit to the deprotected amino group of the resin bound extended structure to further extend the structure or repeating further iteration of the method to further extend the structure. Upon completion of a product of the desired length, the synthesis is terminated.
• a method of adding further random peptide nucleic acid units to an amine terminated peptide nucleic acid oligomer on a solid phase synthesis resin includes selecting a plurality of peptide nucleic acid synthons wherein each of the synthons has a nucleobase that differs from the nucleobase of others of the synthons.
• the method further includes treating the amine terminated unit on the solid phase synthesis resin with the plurality of synthons forming resin bound oligomers having random peptide nucleic acid terminus moieties thereon and repeating further iteration of the method to further extend the oligomer.
• the synthesis is terminated.
• a preselected nucleobase carrying synthon is used during one of said repetitions in place of the plurality of synthon. When so used, this adds the preselected nucleobase synthon to said oligomer and thus fixes that position in the oligomeric compounds.
• a method of adding further random peptide nucleic acid units to an amine terminated peptide nucleic acid oligomer on a solid phase synthesis resin includes selecting a plurality of peptide nucleic acid monomeric synthons wherein each of the synthons has a nucleobase that differs from the nucleobase of others of the synthons.
• the method further includes dividing the resin into portions and treating each of the portions of the amine terminated oligomer on the solid phase synthesis resin with one of the plurality of synthons.
• the method further includes combining all of the portions of resin together and repeating further iteration of the method to further extend the oligomer.
• a preselected nucleobase carrying synthon is used during one of said repetitions, after dividing the resin, in place of the plurality of synthon. When so used, this adds the preselected nucleobase synthon to said oligomer in each of the portions of resin and thus fixes that position in the oligomeric compounds.
• the portions of the resin are not recombined but each is treated separately through further iterations of the method.
• a method of preparing an oligomeric structure composed of mixed peptide nucleic acid units and amino acid units includes selecting one of an amine terminated peptide nucleic acid structure or an amine terminated amino acid structure on a solid phase synthesis resin and where the structure has at least one peptide nucleic acid unit or at least one amino acid unit .
• the method further includes treating the amine terminated oligomer on the solid phase synthesis resin with a peptide nucleic acid monomeric synthon forming a resin bound structure having a terminus peptide nucleic acid moiety thereon.
• the method further includes adding an amino acid monomeric unit to the resin bound structure to extended structure or repeating further iteration of the method to further extend the structure. Upon completion of a product of the desired length, the synthesis is terminated.
• a method of preparing an oligomeric structure composed of peptide nucleic acids on a solid phase synthesis resin includes activating a solid phase synthesis resin with an appropriate agent and treating the activated solid phase synthesis resin with a monoprotected diamine synthon to form a resin bound first synthon with a secondary amine and a protected primary amine as an integral part thereof.
• the method further includes deprotecting the first synthon to form a second synthon having, as an integral part thereof, a secondary amine and a free amine.
• the method further includes treating the second synthon with a 2-haloacetic acid ester to form a third synthon having, as an integral part thereof, a secondary amine and an acetyl ester.
• the method further includes treating the third synthon with a 1-haloacetylnucleo- base to form a fourth synthon having as an integral part thereof, a covalently bound acetylnucleobase and an acetyl ester thereon.
• the method further includes deprotecting the fourth synthon to form a fifth synthon having, as an integral part thereof, a free carboxylic acid and a covalently bound acetylnucleobase thereon.
• the method further includes treating the fifth synthon with a monoprotected ethylenediamine forming an extended first synthon.
• the method further includes repeating further iteration of the method to further extend the oligomeric structure.
• the synthesis is terminated. The termination of the synthesis can take place before or after deblocking the fourth synthon to give either a protected oligomeric peptide nucleic acid compound or a deprotected oligomeric peptide nucleic acid compound
• Chimeric compounds of the invention include compounds of the structure:
• each AA independently, is an amino acid residue
• PNA is a peptide amino acid residue
• the sum of u, v, w, x, y and z is less than 100. In an even more preferred groups of compounds of the invention, the sum of u, v, w, x, y and z is less than 25.
• Compounds of the invention and compounds prepared by the processes of the invention can be used as inhibitors of various enzymes including phospholipase A 2 enzyme.
• compounds of the invention and compounds prepared by the processes of the invention are useful for the treatment of inflammatory diseases including atopic dermatitis and inflammatory bowel disease.
• the compounds of the invention and compounds prepared by the processes of the invention can further be used as gene modulators.
• Compounds of the invention and compounds prepared by the processes of the invention can further be used in diag ⁇ nostics since they are capable of specifically hybridizing to nucleic acids of interest in the etiology of diseases. Further the compounds of the invention can be used as research probes and primers especially for the study of enzyme biochemistry and protein-nucleic acid interactions.
• Figure 1 shows certain sub-monomer peptide nucleic acid synthons utilized in synthetic schemes of the invention
• Figure 2 shows a synthesis scheme for the preparation of peptide nucleic acid oligomeric structures utilizing the sub-monomer synthons of Figure 1;
• Figure 3 shows a synthesis scheme for the preparation of further sub-monomer peptide nucleic acid synthons;
• Figure 4 shows a synthesis scheme for the preparation of peptide nucleic acid oligomeric structures utilizing the sub-monomer synthons of Figure 3;
• Figure 5 shows a synthesis scheme for the preparation of further sub-monomer peptide nucleic acid synthons
• Figure 6 shows a synthesis scheme for the preparation of peptide nucleic acid oligomeric structures utilizing the sub-monomer synthons of Figure 5;
• Figure 7 shows one logic flow scheme for the preparation of a chimeric oligomeric structure of the form Gly-
• Y is an amino acid in accordance with preferred embodiments.
• Figure 8 shows a synthesis scheme for the preparation of peptide nucleic acid oligomeric structures utilizing sub- monomer synthons.
• Peptide nucleic acids have been shown to have higher binding affinities (as determined by their Tm's) for both DNA and RNA than that of DNA or RNA to either DNA or RNA. This increase in binding affinity makes these peptide nucleic acid oligomers especially useful as molecular probes and diagnostic agents for nucleic acid species.
• Tm's binding affinities
• oligomeric peptide nucleic acids and libraries of peptide nucleic acids can be formed utilizing various combinatorial techniques. Heretofore, it was known only to prepare peptide nucleic acid from preformed complete monomeric units. Further it has now been found that oligomeric peptide nucleic acids, of either pre-determined or random sequences, can be prepared using sub-monomer synthons. Such sub-monomer synthons are especially useful to prepare random sequence peptide nucleic acids and libraries of such random sequence peptide nucleic acids.
• peptide nucleic acid combinatorial libraries in preparing peptide nucleic acid combinatorial libraries, four simple nucleobase building blocks, employed either as fully constructed monomer units or as pre-monomer subunits (sub-monomers) , are assembled stepwise to the desired monomer on a resin. Further, chimeric structures can be formed by including additional common amino acid-based building blocks in the libraries.
• Libraries of oligomeric PNA or chimeric PNAs are sources of compounds for therapeutic and diagnostic agent development. Further final therapeutic agents can be selected from the library.
• this invention embodies libraries comprising either peptide nucleic acids alone or in conjunction with amino acids, as monomer units to create libraries with the ability to bind to biomolecules such as RNA, DNA, or proteins. For binding to nucleic acids, these libraries have the benefit of being able to bind without the charged backbone found in oligonucleotide libraries.
• the previous peptide and nucleotide libraries all possess regular backbones with the diversity stemming from the side chains appended to the regular backbone.
• chimeric and non-regular backbone libraries can be created.
• the ability to have a non-regular backbone enhances diversity in a away unattainable in currently known library systems.
• an amino acid(s) capable of inducing turns for example proline, are incorporated into the libraries to provide libraries with secondary structure that can be controlled from the current knowledge for peptide turn motifs.
• Such libraries with an amino acid induced turn are deemed useful for binding to oligonucleotide secondary structures such as stem-loops or hairpins and pseudoknots or duplexes containing a bulged base that induces a helical axis tilt (see Westhof, E., and Jaeger, L., Curr Opinions Struct . Biol . , 1992, 2, 327-333 and Ecker, D.J., et al., Science, 1992, 257, 958-961) .
• the present invention combines unique peptide nucleic acid monomer units with the standard set of amino acids, in either D or L configurations and/or additional unnatural . or ⁇ -amino acids to generate a library.
• the libraries generated can be used to screen for compounds binding to proteins of interest such as binding to and the inhibition of an enzyme.
• these libraries possess the capability to bind at the same time to proteins and to RNA or DNA in close proximity. This has advantages in interfering or enhancing binding of transcription factors or RNA/DNA processing enzymes to their target oligonucleotides or in binding to oligonucleotide secondary structures to stabilize the structure and prevent transcription.
• the libraries thus contains simple monomers bearing side chains with the potential for interactions of the following types: hydrogen-bond donor and acceptor, ionic, polar, hydrophobic and aromatic.
• libraries are prepared from known peptide nucleic acid monomers such as those described in the PCT patent applications WO 92/20702, WO
• a mixed synthon method is utilized.
• a mixture of synthons like in their chemical reactivity towards a growing oligomer structure but differing as to a functional nucleobase carried thereon, are utilized to added a randomly selected nucleobase carrying synthon on to the growing oligomeric structure.
• libraries of randomly sequenced peptide nucleic acid oligomers are formed.
• diversity is introduced into the libraries via splitting the synthesis resin of a solid support resin, into a number of fraction.
• each fraction is then treated with one of the nucleobase carrying synthon to add that synthon to the growing oligomeric structure.
• the resin fractions are combined, mixed and further fractionated for the addition of a further nucleobase carrying synthon.
• positions can be "fixed" in the growing oligomeric structure, by reacting the totality of the resin with a single synthon or by reacting each fraction with the same known synthon or with different but known synthons.
• peptide nucleic acids are synthesized via new synthetic procedures that utilize several sub-monomers that are combined during the synthetic scheme to produce complete peptide nucleic acid units.
• a sub-monomer is defined as a building blocks that is less than the totality of a complete monomeric unit. Together two or more sub-monomers are combined to give the same structure as would be achieved if a complete monomer were utilized.
• the sub-monomer route has various advantages .
• One such advantage is the fact that certain common sub-monomers that form a part of each monomeric unit of a particular synthetic scheme can be prepared but once in large quantity. Further, less completed synthons bearing the individual nucleobase need to prepared. Further, advantage can be taken of the reactivity of the sub-monomers - that is the sub- monomers are made reactive such that additional coupling agents need not be used to effect growth of the oligomeric structure.
• the sub-monomer synthetic process of the invention are useful for not only synthesizing peptide nucleic acids of known or pre-determined sequence but also for the synthesis of random sequence peptide nucleic acids and libraries of such randomly synthesized peptide nucleic acids. This is particularly useful for certain combinatorial screening techniques.
• a key feature of combinatorial techniques is that thousands of molecules can be screened in a small number of assays.
• concentration of the active molecule is selected to be sufficiently great such that the molecule can be detected within the sensitivity of the chosen assay.
• the number of unique oligomer sequences within a subset produced via a combinatorial technique depends on the length of the oligomer and the number of different monomers employed. The number of sequences can be determined by raising the number of monomers to a power equal to the number of random positions. This is illustrated in Table I. Table I also indicates the concentration of each sequence when the subset concentration is 100 ⁇ M, a typical high-test concentration.
• the number of monomers and their length can be based upon an estimate of the expected IC 50 (i.e., a concentration at which 50% of enzyme activity is inhibited) that is desirable in a final oligomeric compound.
• the expected IC 50 i.e., a concentration at which 50% of enzyme activity is inhibited
• the complexities shown in Table I are acceptable, that is, the libraries shown in Table I have complexities that would allow detection of a unique sequence with an IC 50 of about 100 nM or less.
• the library will have a length of five monomer units, XNNNN, where N is an equal molar mixture of monomer units and X is a different monomer unit in each of the five subsets.
• N is an equal molar mixture of monomer units
• X is a different monomer unit in each of the five subsets.
• the fixed position can be selected as the right end of the molecule. After assay for inhibition of PLA 2 activity as described below, position X is fixed with the residue giving the greatest inhibition and the next subset is synthesized and screened. The fixed position then shifts towards the left end of the oligomer as unrandomization proceeds. Five rounds of synthesis and screening are required to determine a unique inhibitor.
• the monomer design of the invention allows for the combination of rational drug design with a screen of thousands of compounds.
• One such screen wherein libraries of peptide nucleic acids oligomer and chimeric peptide nucleic acid- peptides, is a screen for activity against PLA 2 .
• Phospholipases A 2 are a family of enzymes that hydrolyze the sn-2 ester linkage of membrane phospholipids resulting in release of a free fatty acid and a lysophospholipid [see Dennis, E. A., The Enzymes, 1983, ed. Boyer, P. D. (Academic Press, New York) , Vol. 16, pp. 307-353] .
• the PLA 2 -catalyzed reaction is the rate-limiting step in the release of a number of pro-inflam ⁇ matory mediators.
• Arachidonic acid a fatty acid commonly linked at the sn-2 position, serves as a precursor to leuko- trienes, prostaglandins, lipoxins and thromboxanes .
• the lyso- phospholipid can be a precursor to platelet-activating factor.
• PLA 2 is regulated by pro-inflammatory cytokines and thus occupies a central position in the inflammatory cascade (see Dennis, ibid. ; Glaser, K. B., Mobilio, D., Chang, J. Y. & Senko, N., TiPs Reviews, 1992, 14 , 92-98; and Pruzanski, W. , Scott, K. , Smith, G. , Rajkovic, I., Stefanski, E. & Vadas, P., Inflammation 1992, 16, 451-457) .
• PLA 2 activity All mammalian tissues evaluated thus far have exhibited PLA 2 activity. At least three different types of PLA 2 are found in humans: pancreatic (type I) , synovial fluid (type II) and cytosolic. Other studies suggest that additional isoenzymes exist. Type I and type II, the secreted forms of PLA 2 , share strong similarity with phospholipases isolated from the venom of snakes. The PLA 2 enzymes are important for normal functions including digestion, cellular membrane remodeling and repair, and in mediation of the inflammatory response. Both cytosolic and type II enzymes are of interest as therapeutic targets.
• the type II PLA 2 enzyme from synovial fluid is small (about 14 kD) and distinguished from the type I enzymes (e.g. pancreatic) by sequence and the pattern of disulfide bonds present - both types require calcium for activity (Dennis, i-bid.) .
• the crystal structures of secreted PLA 2 enzymes from venom and pancreatic PLA 2 with and without inhibitors have been reported (Scott, D. L., White, S. P., Otwinowski, Z., Yuan, W. , Gelb, M. H. & Sigler, P. B., Science, 1990, 250 , 1541-1546) .
• the walls of this cleft contact the hydrocarbon portion of the phospholipid and are composed of hydrophobic and aromatic residues.
• the positively-charged amino-terminal helix is situated above the opening of the hydrophobic cleft .
• the N-terminal portion is the interfacial binding site (Achari, A., Scott, D., Barlow, P., Vidal, J. C, Otwinowski, Z., Brunie, S. & Sigler, P. B., Cold Spring Harbor Symp . Quant . Biol . , 1987, 52 , 441-452; Cho, W. , Tomasselli, A. G., Heinrikson, R. L. & Kezdy, F. J.
• PLA 2 displays a lag phase during which the enzyme adsorbs to the substrate bilayer and a process called interfacial activation occurs. This activation may involve desolvation of the enzyme/lipid interface or a change in the physical state of the lipid around the cleft opening.
• the evidence favoring this hypothesis comes from studies revealing that rapid changes in PLA 2 activity occur concurrently with changes in the fluorescence of a membrane probe (Burack, W. R. , Yuan, Q. & Biltonen, R. L., Biochemistry, 1993, 32, 583-589) .
• PLA 2 activity is maximal around the melting tempera ⁇ ture of the lipid, where regions of gel and liquid-crystalline lipid coexist. This is also consistent with the sensitivity of PLA 2 activity to temperature and to the composition of the substrate, both of which can lead to structurally distinct lipid arrangements separated by a boundary region. Fluorescence microscopy was used to simultaneously identify the physical state of the lipid and the position of the enzyme during catalysis (Grainger, E. W. , Reichert, A., Ringsdorf, H. & Salesse, C, FEBS Lett . , 1989, 252, 73-82) . These studies clearly show that PLA 2 binds exclusively at the boundary region between liquid and solid phase lipid.
• PLA 2 While the hydrolysis of the secondary ester bond of 1,2-diacylglycerophospholipids catalyzed by the enzyme is rela ⁇ tively simple, the mechanistic and kinetic picture is clouded by the complexity of the enzyme-substrate interaction.
• a remarkable characteristic of PLA 2 is that maximal catalytic activity is observed on substrate that is aggregated (i.e. phospholipid above its critical micelle concentration) , while low levels of activity are observed on monomeric substrate (Dennis, ibid. ; Achari, ibid. ) .
• competitive inhibitors of PLA 2 either have a high affinity for the active site of the enzyme before it binds to the substrate bilayer or partition into the membrane and compete for the active site with the phospholipid substrate.
• a sulfonyl moiety is defined to include both aryl and alkyl radicals.
• sulfonyl includes tosylates, brosylates, nosylates, esylates, triflates, nonaflates and tresylates.
• halo and halide moieties include the halogens F, Cl, Br or I.
• Solid phase amino acid synthesis resin suitable for use with the invention include resins such as hydroxymethyl polystyrene, PAM, Tentagel, Wang or MBHA. Such resins can be utilized in both batch wise synthesis or via machine synthesis. In practicing batch wise synthesis, for facilitating removal of residual reactants from polystyrene resin, after completion of a reaction step, the resin is washed and dried to remove all solvent. The resin is then re-swollen for the next procedure. Machine synthetic techniques are those known in the arts of peptide synthesis.
• One preferred sub-monomer synthon of the invention is a bifunctional acetyl synthon having a halide functional group and one of either an alkyl halide or sulfonyl functional group.
• Such preferred bifunctional acetyl synthons include haloacetyl halide or sulfonylacetyl halide synthons.
• a particular preferred groups of such synthons include tosyl acetyl halide, mesyl acetyl halide, brosyl acetyl halide, nosyl acetyl halide, triflyl acetyl halide, nonaflyl acetyl halide or tresyl acetyl halide synthons as well as chloroacetyl chloride, chloroacetyl bromide, bromoacetyl chloride, bromoacetyl bromide, iodoacetyl chloride, iodoacetyl bromide, fluoro acetylchloride and fluoro acetylbromide.
• preferred amine protecting groups include tetramethyl-1, 2-disilylethylene and trimethylsilylethoxy- carbonyl both of which can be removed with fluoride ion.
• Other amine protecting groups for use in the invention include t- butyloxycarbonyl removable with trifluoroacetic acid in CH 2 C1 2 , DMF or equivalent solvent; fluorenylmethyloxycarbonyl removable with piperidine in DMF; or triphenylmethyl or one of the possible methoxysubstituted triphenymethyl protecting groups, removable with trichloroacetic acid in dichloromethane or the like.
• an acid scavenger for reaction of the certain sub-monomer synthons of the invention or certain bifunctional acetyl synthons of the invention with support resin or growing oligomer, the concurrent use of an acid scavenger is preferred.
• acid scavengers include tertiary alkyl amines such as triethylamine and related trialkyl amine compounds including but not limited to diisopropylethylamine, dicyclohexylethylamine, dicyclo- hexylymethylamine, 1, 2, 2, 6, 6-pentamethyl piperidine and N- methyl morpholine.
• Figure 2 illustrates a synthetic scheme for the preparation of peptide nucleic acids of predesigned sequence or peptide nucleic acid combinatorial libraries of any desired length utilizing certain sub-monomer building blocks or synthons as are shown in Figure 1.
• One of the synthons is a synthon carrying one of the individual nucleobases .
• the synthons utilized for this synthesis can be characterized as an acetyl ⁇ nucleobase fragment, e.g. 2- (nucleobase) acetyl chloride; an ethylenediamine fragment, e.g.
• the assembly of the desired peptide nucleic acid oligomer libraries is carried out, as for instance, by attaching a bromoacetyl chloride or mesylacetyl chloride synthon to a solid phase amino acid synthesis resin such as hydroxymethyl polystyrene, PAM, Tentagel, or Wang. After attachment, the resin bound acetyl chloride synthon is reacted with the ethylenediamine synthon in the presence of an acid scavenger to displace the 2-halo element, i.e. the 2-bromo element, of the original bromoacetyl fragment.
• a bromoacetyl chloride or mesylacetyl chloride synthon to a solid phase amino acid synthesis resin such as hydroxymethyl polystyrene, PAM, Tentagel, or Wang.
• the unprotected secondary amine of the ethylene diamine portion of this resulting fragment is next reacted with a 1- haloacetylnucleobase synthon, if a fixed position is desired, and, if a randomized position is desired, in one embodiment of the invention with a mixture of the desired substituted halo acetyl synthons.
• the resin can be split into portion and each portion reacted with a different 1-haloacetylnucleobase synthon. For each of these, the 1-haloacetylnucleobase or 1-haloacetylnucleobases are added in the presence of an acid scavenger.
• the acid scavenger is a hindered tertiary amine base; however, other acid scavengers can also be used. If the resin is split, it can be recombined. Next fluoride ion is used to deprotect the terminal amine of the ethylene diamine fragment . At this point in the synthesis a first peptide nucleic acid unit has been synthesized on the resin.
• Formation of the second peptide nucleic acid unit is effected by reacting the terminal amine of the first peptide nucleic acid unit with further haloacetyl halide or sulfonyl- acetyl halide synthon, again in the presence of an acid scavenger, to create the glycine portion of the second peptide nucleic acid unit now attached to the first peptide nucleic acid unit.
• This glycine moiety is now reacted with the ethylenediamine synthon, again in the presence of an acid scavenger, to add the ethylamine portion of the second peptide nucleic acid unit to the growing peptide nucleic acid oligomer.
• a third peptide nucleic acid unit is then added in the same manner by again reacting the terminal amine with a further haloacetyl halide or sulfonylacetyl halide synthon as before in the presence of a hindered tertiary amine base.
• the process is repeated as many times as is necessary to prepare the desired f ⁇ lly protected, resin-attached peptide nucleic acid library with the desired number of fixed and randomized positions .
• the completed peptide nucleic acid can then be deprotected and cleaved from the resin or cleaved first from the resin and then deprotected.
• the blocked peptide nucleic acids could remain on the resin and treated with an appropriate biological testing medium to assay for activity.
• Variations possible using this method include the use of alternate (substituted) haloacetyl units, such as ⁇ .-methyl or ⁇ -protected hydroxymethyl haloacetyl halide at any position in the oligomer desired. Substitutions or chain length variation in the diaminoethane synthon are also possible and substitution on the acetyl synthon are also considered within the scope of the invention. Variations also include the use of alternate synthons, where any substituent desired to provide binding motifs such as charge, hydrogen bond accepting or donating properties, or hydrophobic and aromatic pi- interactions at any position in the oligomer desired. Substitutions or chain length variation in the synthons are also possible and substitution on the acetyl portion are also with the scope of this method of the invention. The repeating nature of the synthetic sequence of
• Figure 2 can be interrupted at anytime there is a free terminal amine present and an amino acid can be introduced by standard peptide coupling techniques, either as a single fixed amino acid residue or a mixture of amino acids to provide a random position before continuing as described above to the desired length oligomer.
• This synthetic sequence can also be utilized to extend a normal peptide with peptide nucleic acid units.
• a second method for the preparation of peptide nucleic acids of a predesigned sequence or a peptide nucleic acid combinatorial libraries of any desired length illustrated in Figure 4, further sub-monomer building blocks or synthons are assembled. These sub-monomer are illustrated in Figure 3.
• the construction of a peptide nucleic acid of predetermined sequence or a peptide nucleic acid combinatorial library of any desired length is effected by treating a resin (or a preexisting peptide nucleic acid or amino acid unit on a resin) with an acetyl synthon that has two active functional groups thereon to add the acetyl synthon to the resin (or existing peptide nucleic acid or amino acid unit) .
• ethylenediamine-acetyl ⁇ nucleobase synthon wherein one of the amino groups of the diamine is present in a blocked or protected form, e.g. 2- (tetramethyl-1, 2-disilylethylene) -1- [ (2-nucleobase) acetyl] - ethylenediamine, if a fixed position is desired, and employing a mixture of such synthons (or split portions of the resin, as described for the previous method) , if a randomized position is desired.
• 2- (tetramethyl-1, 2-disilylethylene) -1- [ (2-nucleobase) acetyl] - ethylenediamine if a fixed position is desired, and employing a mixture of such synthons (or split portions of the resin, as described for the previous method) , if a randomized position is desired.
• the assembly of the desired peptide nucleic acid oligomers libraries is carried out by attaching a 2- (tetramethyl-1, 2-disilylethylene) -1- [2- (nucleobase) acetyl] ethylenediamine synthon to a solid phase amino acid synthesis resin having an haloacetylated amine function such as MHBA or an aminoacid loaded resin.
• a solid phase amino acid synthesis resin having an haloacetylated amine function such as MHBA or an aminoacid loaded resin.
• the blocking or protecting group on the terminal amine (of the ethylenediamine fragment of the second synthon) is deprotected.
• fluoride ion is utilized to deprotect the terminal amine of the ethylenediamine fragment.
• Such deprotection is again effected using fluoride ion if a tetramethyl-1,2- disilylethylene protecting group is utilized. As before, this deprotects the terminal amine of the ethylenediamine fragment.
• the third peptide nucleic acid unit is then added by again reacting the existing oligomer on the resin with a halo ⁇ acetyl halide fragment followed by treating with a third 2- (tetramethyl-1, 2-disilylethylene) -1- [2- (nucleobase) acetyl] - ethylenediamine synthon. This process is repeated through as many iterations as is necessary to prepare the desired fully protected, resin-attached peptide nucleic acid or peptide nucleic acid library. The completed peptide nucleic acid or library can then be deprotected and cleaved from the resin or cleaved first from the resin and then deprotected.
• Variations possible under this second synthetic method of the invention include the use of alternate 2- (tetra ⁇ methyl-1, 2-disilylethylene) -1- [2- (nucleobase) acetyl] ethyl ⁇ enediamine synthons, where any substituent desired to provide binding motifs such as charge, hydrogen bond accepting or donating properties, or hydrophobic and aromatic pi- interactions at any position in the oligomer desired. Substitutions or chain length variation in the diaminoethane unit are also possible and substitution on the acetyl portion are also with the scope of this method of the invention.
• this synthetic sequence can be interrupted at anytime there is a free terminal amine present and an amino acid can be introduced by standard peptide coupling techniques, either as a single fixed amino acid residue or a mixture of amino acids to provide a random position before continuing as described above to the desired length oligomer.
• the synthetic sequence can also be utilized to extend a normal peptide with peptide nucleic acid units.
• Figure 6 This method utilizes further sub- monomer building blocks or synthons as illustrated in Figure 5.
• a peptide nucleic acid of predetermined sequence or a peptide nucleic acid combinatorial library of any desired length is effected by treating an amine terminated resin (or an amine terminated preexisting peptide nucleic acid or amino acid unit on a resin) with a oxo-morpholine synthon that includes a nucleobase thereon.
• a oxo-morpholine synthon that includes a nucleobase thereon.
• Suitable for use as this synthon is a 1- [2- (nucleobase)carbonylmethyl] -3-oxo-morpholine synthon, e.g.
• the assembly of the desired peptide nucleic acid oligomers is carried out by attaching a 1- [2- (nucleobase) car- bonylmethyl] -3-oxo-morpholine synthon to a solid phase amino acid synthesis resin having an amine function such as MHBA or a peptide nucleic acid or an amino acid loaded resin.
• the resin is reacted with the synthon by treating the resin with the 1- [2- (nucleobase) carbonylmethyl] -3-oxo-morpholine synthon to added a modified peptide nucleic acid unit.
• the modified peptide nucleic acid unit is a unit that is terminated with a hydroxyl functionality versus an amine functionality of a normal peptide nucleic acid unit.
• the terminal modified peptide nucleic acid unit is then converted to a normal peptide nucleic acid unit by conversion of the terminal hydroxyl group to an amine group. This can be effected by an method compatible with the remainder of the oligomer and resin. A particularly preferred method is via a Mitsunobu reaction.
• the resulting unprotected alcohol fragment located on the resin having a single unit or a growing oligomer thereon, is treated with diethylazodicarboxylate, triphenylphosphine and bis (t-butoxycarbonyl) imide or with dipheylphosphoryl azide coupled with reduction to convert the hydroxyl group to an amine group followed by removing the t-BOC group with trifluoroacetic acid. In doing so, this converts the just added unit to a normal peptide nucleic acid unit.
• a second peptide nucleic acid unit is then added via the same set of reactions, namely, reacting the existing peptide nucleic acid unit or peptide nucleic acid oligomer on the resin with a second 1- [2- (nucleobase) carbonylmethyl] -3-oxo- morpholine synthon followed by conversion of the resulting unprotected alcohol group with diethylazodicarboxylate, tri ⁇ phenylphosphine, and bis (t-butoxycarbonyl) imide to an amine followed by removing the t-BOC group with trifluoroacetic acid.
• peptide nucleic acid monomer units are linked to form an oligomer using a modification of method for synthesizing peptides on solid supports as pioneered by Merrifield.
• a SURF selection technique in combination with a SURF selection technique, an equimolar or essentially equimolor incorporation of each monomer at each randomized position is desired. Since the coupling rates of the monomers may vary, in one embodiment, monomers are coupled separately to a portion of the solid support as follows :
• a solid support usually 1-10% crosslinked poly ⁇ styrene or polyethylene glycol grafted polystyrene, is separated into portions (of number equal to the number of monomers in the library) of equal weight. Each of these is reacted with one of the desired N-amino and side chain protected free carboxylic acid peptide nucleic acid or peptide nucleic acid-like monomers using hydroxybenzotriazole and a carbodiimide coupling agent or one of the numerous uronium salts.
• the N-terminal amino protecting group is cleaved using trifluoroacetic acid in CH 2 C1 2 , DMF or equivalent solvent to generate a new terminal amino functionality, if the protecting group is a t-butyloxycarbonyl, or piperidine in DMF, if the protecting group is a fluorenylmethyloxycarbonyl, or trichloro- acetic acid in dichloromethane or the like if the protecting group is a triphenylmethyl or one of the possible methoxy- substituted triphenymethyl protecting groups at the end of the extended oligomer.
• the extent of the coupling reaction is optimized to be ⁇ 90% completed by varying the monomer and coupling agent concentrations and total equivalents and the coupling time. After a coupling, the support is mixed thoroughly, then divided equally and monomers are again reacted individually to a portion of the support . This cycle is repeated for each random position until desired a "fixed" position is reached.
• each monomer is reacted individually to a portion of the support, but the portions are not mixed. Instead each subset is further divided into the number of portions corresponding to the number of monomers. Each portion of support is then reacted with a different monomer, followed by mixing as above. Repeating this cycle for each of the different subsets of supports results in randomization in positions following the fixed position in the sequence. The resulting subsets are unique only in the fixed position.
• oligomers are cleaved from the solid support and side chain protecting groups are removed by incubation for 1-2 h at room temperature in an appropriate deprotection mixture such as trifluoroacetic acid/trifluoromethanesulfonic acid containing cresol and arylmethyl sulfide as cation scavengers.
• an appropriate deprotection mixture such as trifluoroacetic acid/trifluoromethanesulfonic acid containing cresol and arylmethyl sulfide as cation scavengers.
• the supernatant containing the oligomer is then removed from the spent resin.
• the oligomer is desalted and protecting groups byproducts removed by HPLC or size exclusion chromatography.
• peptide nucleic acid monomer units are linked to form an oligomer using a modification of methods for synthesizing peptides on solid supports as pioneered by Merrifield.
• an equimolar or essentially equimolor incorporation of each monomer at each randomized position is desired. Since the coupling rates of the monomers may vary, in this embodiment, the coupling rates of the monomers to each other are determined and monomers concentrations are adjusted - based on the determined coupling rates - so that the relative coupling rate of each monomer in the mixture of incoming monomer (activated form) is the same.
• the coupling mixture is reacted with the resin/solid support at each step in the oligomer synthesis where a random position is desired as follows:
• a solid support usually 1-10% crosslinked polystyrene or polyethylene glycol grafted polystyrene, is reacted with the mixture of incoming monomer, with adjusted concentrations of the desired N-amino and side chain protected free carboxylic acid peptide nucleic acid or peptide nucleic acid-like monomers using hydroxybenzotriazole, and a carbodiimide coupling agent or one of the numerous uronium salts.
• the N-terminal amino protecting groups are cleaved using trifluoroacetic acid in CH 2 C1 2 or DMF or some similar solvent to generate a new terminal amino functionality, if the protecting group is a t-butyloxycarbonyl and piperidine in DMF if the protecting group is a fluorenylmethyloxycarbonyl or trichloroacetic acid in dichloromethane or the like if the protecting group is a triphenylmethyl or one of the possible methoxysubstituted triphenymethyl protecting groups at the end of the extended oligomer.
• the extent of the coupling reaction is optimized to be ⁇ 90% completed by varying the monomer and coupling agent concentrations and total equivalents and the coupling time. After a coupling, the support is washed free of residues, the terminal deprotection reaction and coupling cycle is repeated for each random position until the "fixed" position is reached.
• each monomer is reacted individually to a portion of the support.
• the portions used equals the number of monomers to be used to fix the desired subsets. After this the subsets are not mixed. Instead each subset is further deprotected and reacted with the adjusted activated monomer mixture. Repeating this cycle for each of the different subsets of supports results in randomization in positions following the fixed position in the sequence as a series of library subsets. The resulting subsets are unique only in the fixed position.
• oligomers are cleaved from the solid support and side chain protecting groups removed by incubation for 1-2 h at room temperature in an appropriate deprotection mixture such as trifluoroacetic acid/trifluoromethanesulfonic acid containing cresol and arylmethyl sulfide as cation scavengers.
• an appropriate deprotection mixture such as trifluoroacetic acid/trifluoromethanesulfonic acid containing cresol and arylmethyl sulfide as cation scavengers.
• the supernatant containing the oligomer is then removed from the spent resin.
• the oligomer is desalted and protecting groups byproducts are removed by HPLC or size exclusion chromatography.
• Figure 8 illustrates a synthetic scheme for the preparation of peptide nucleic acids of predisigned sequence or peptide nucleic acid combinatorial libraries of any desired length utilizing certain sub-monomer building blocks or synthons.
• One of the synthons is a synthon carrying the individual nucleobases.
• Another synthon is used for introducing the aminoethyl and still another is used to introduce the acetyl portion.
• the synthons utilized for this synthesis can be characterized as an acetylnucleobase fragment, e.g. 2- (nucleobase) acetyl chloride; an ethylenediamine fragment, e.g.
• the assembly of the desired peptide nucleic acid oligomer libraries is carried out, as for instance, by reacting a protected ethylenediamine synthon such as N- (2-trimethyl- silylethoxycarbonyl) -1,2-diaminoethane in the presence of an acid scavenger, to an activated solid phase synthesis resin such as methylhydroxycarbonylchloride polystyrene.
• a protected ethylenediamine synthon such as N- (2-trimethyl- silylethoxycarbonyl) -1,2-diaminoethane
• an activated solid phase synthesis resin such as methylhydroxycarbonylchloride polystyrene.
• the resin is activated with a reagent such as phosgene.
• Next fluoride ion is used to deprotect the terminal amine of the ethylene diamine fragment and the resulting free amine is treated with a haloacetyl synthon such as t-butyl bromoacetate, to couple the two fragments giving a secondary amine and a protected terminal amine thereon.
• This resulting fragment is next reacted with a 1-haloacetylnucleobase synthon, if a fixed position is desired, and, if a randomized position is desired, in one embodiment of the invention with a mixture of the desired substituted halo acetyl synthons.
• the resin can be split into portions and each portion reacted with a different 1- haloacetylnucleobase synthon.
• each of these, the 1-haloacetylnucleobase or 1-haloacetylnucleobases are added in the presence of an acid scavenger.
• an acid scavenger is a hindered tertiary amine base; however, other acid scavengers can also be used.
• the resin is split, it can be recombined. At this point in the synthesis a first peptide nucleic acid unit has been synthesized on the resin.
• the acetic acid ester portion of the haloacetyl fragment is deprotected to give a carboxyl group which is treated with an another ethylenediamine synthon, in the presence of an appropriate coupling agent, to initiate synthesis of the second peptide nucleic acid unit in the PNA oligomeric structure.
• the above iterative process is repeated as many times as is necessary to prepare the desired fully protected, resin- attached peptide nucleic acid library with the desired number of fixed and randomized positions.
• the completed peptide nucleic acid can then be deprotected and cleaved from the resin or cleaved first from the resin and then deprotected.
• the blocked peptide nucleic acids could remain on the resin and treated with an appropriate biological testing medium to assay for activity.
• Variations possible using this method include the use of alternate (substituted) haloacetyl units, such as ⁇ -methyl or ⁇ -protected hydroxymethyl haloacetyl halide at any position in the oligomer desired. Substitutions or chain length variation in the diaminoethane synthon are also possible and substitution on the acetyl synthon are also considered within the scope of the invention. Variations also include the use of alternate synthons, where any substituent desired to provide binding motifs such as charge, hydrogen bond accepting or donating properties, or hydrophobic and aromatic pi- interactions at any position in the oligomer desired. Substitutions or chain length variation in the synthons are also possible and substitution on the acetyl portion are also with the scope of this method of the invention.
• the repeating nature of the synthetic sequence of Figure 8 can be interrupted at anytime there is a free terminal carboxyl present and an amino acid can be introduced by standard peptide coupling techniques, either as a single fixed amino acid residue or a mixture of amino acids to provide a random position before continuing as described above to the desired length oligomer.
• This synthetic sequence can also be utilized to extend a normal peptide with peptide nucleic acid units.
• a preferred group of synthons include N- [2- (thymin-1-yl) acetyl] -N- [2- (t- butyloxycarbonyl) -2-ethylamino] glycine; N- ⁇ 2- [N 4 - (benzyloxy ⁇ carbonyl) cytosin-1-yl] acetyl ⁇ -N- [2- (t-butyloxycarbonyl) -2- ethylamino] glycine; N- ⁇ 2- [N 4 - (benzyloxycarbonyl) adenin-9-yl] - acetyl ⁇ -N- [2- (t-butyloxycarbonyl) -2-ethylamino] glycine; or N- ⁇ 2- [N 2 - (benzyloxycarbonyl) guanin-9-yl] acetyl ⁇ -
• N6- (Benzyloxycarbonyl) -9- (chlorocarbonylmethyl) adenine Oxalyl chloride (6.3 g, 50 mmol) is added dropwise over 5 minutes to a solution of N6- (benzyloxycarbonyl) -9- (carboxymethyl) adenine (16.6 g, 50 mmol) dissolved in dichloromethane (200 mL) .
• the reaction is stirred until gas evolution has ceased and then for an additional 2 hours.
• the reaction mixture is evaporated to an oil .
• N- (t-Butyloxycarbonyl) -1,2-diaminoethane (8.0 g, 50 mmol) is dissolved in THF (200 mL) , diisopropylethylamine (6.5 g, 50 mmol) is added and the solution cooled to O °C.
• diisopropylethylamine (6.5 g, 50 mmol) is added and the solution cooled to O °C.
• trimethylsilylethoxy- carbonylchloride 9.0 g, 50 mmol
• the reaction is filtered and the filtrate is evaporated to an oil.
• This oil is dissolved in 100 mL of diethyl ether and washed with dilute HCI solution (3x25 mL) , dried, filtered and evaporated to give an oil.
• Hydroxymethyl substituted polystyrene beads (2.0 g, 1.0 mmol/gm loading, 1% crosslinked) is swelled in dichloro- ethane (150 mL) .
• Triethyl amine (1.0 g, 10 mmol) and bromoacetyl bromide (2.0 g, 10 mmol) are added to the swollen resin.
• the reaction mixture is stirred for 18 hours then filtered and washed 10 times with 100 mL of dichloromethane, then two times with diethyl ether, and is dried at low vacuum at 40 °C for 18 hours.
• the free flowing resin powder is used as is - it can be checked for extent conversion by gel phase 13 C-NMR using the procedure of Epton, R. , Polymer, 1980, 21 , 1367-1371.
• the resin from Example 6 is swollen in dichloroethane (200 mL) and to this is added N- (trimethylsilylethoxycarbonyl) - 1, 2-diaminoethane hydrochloride (2.4 g, 10 mmol) and triethyl amine (2.0 g, 20 mmol) .
• the reaction mixture is heated to 40 °C for 18 hours, then cooled and the resin and washed 5 times with dichoromethane (50 mL) , then 3 times with diethyl ether (100 mL) , and dried at low vacuum at 40 °C for 18 hours.
• the free flowing resin powder is used as is and can be checked for extent conversion by gel phase 13 C-NMR as per Epton, Ibid. .
• reaction mixtures are independently heated to 40 °C for 18 hours, then cooled and the resin is washed 5 times with dichoromethane (50 mL) , then 3 times with diethyl ether (lOOmL) , and is dried at low vacuum at 40 °C for 18 hours.
• the independent portions of the resin are combined together and the free flowing resin powder directly used in Example 9.
• Example 8 The resin from Example 8 is swollen in dichloromethane (200 mL) and to this is added tetrabutylammonium fluoride in THF (1.0 M, 1.0 mL) and the suspension stirred for 8 hours . The resin is then washed with dichloromethane containing 0.1% tetrabutyl ammonium chloride (10x25 mL) , 5 times with dichloromethane (25 mL) , and 3 times with diethyl ether (100 mL) , and is dried at low vacuum at 40 °C for 18 hours. The free flowing resin powder is used as is . It is checked for extent conversion by gel phase 13 C-NMR as per Epton, Ibid . .
• Example 9 The resin from Example 9 is swollen in dichloromethane (200 mL) and this is added triethyl amine (1.0 g, 10 mmol) and bromoacetyl bromide (2.0 g, 10 mmol) . The reaction mixture is stirred for 18 hours then filtered and washed 10 times with 100 mL of dichloromethane, then two times with diethyl ether, and is dried at low vacuum at 40 °C for 18 hours.
• the resin from Example 10 is swollen in dichloro ⁇ methane (200 mL) and to this is added N- (trimethylsilylethoxy- carbonyl) -1,2-diaminoethane hydrochloride (2.4 g, 10 mmol) and triethyl amine (2.g, 20 mmol) .
• the reaction mixture is heated to 40 °C for 18 hours, then cooled and the resin is washed 5 times with dichoromethane, then 3 times with diethyl ether (100 mL) , and is dried at low vacuum at 40 °C for 18 hours.
• the resin from Example 11 is swollen in dichloroethane (200 mL) and to this is added 1- chlorocarbonylmethyl thymine (2.0 g, 10 mmol) and triethyl amine (2,0 g, 20 mmol) .
• the reaction mixture is heated to 40 °C for 18 hours, then cooled and the resin is washed 5 times with dichoromethane (50 mL) , then 3 times with diethyl ether (100 mL) , and is dried at low vacuum at 40 °C for 18 hours.
• the free flowing resin powder is used as is.
• Example 12 Extension of Backbone and Addition of Further Nucleobases
• the resin from Example 12 is deblocked as per the procedure of Example 9.
• a further known nucleobase is added utilizing the procedures of Examples 10, 11 and 12.
• a further random nucleobase is added utilizing either the procedure of Example 8a followed by the procedures of Examples 10 and 11 or via the procedure of Example 8b followed by the procedures of Examples 10 and 11. The required number of iterations of the combinations of procedures is effected to complete the oligomer of the desired length.
• a peptide is prepared using standard solid phase Merrifield peptide synthesis building the peptide from carboxyl end toward the amine end.
• the amine terminated peptide is then extended with peptide nucleic acid units utilizing the procedures of Example 13 to either added nucleobases at fixed positions or, using the combinatorial techniques of Example 8a or 8b, to added random nucleobases at any particular position.
• EXAMPLE 15 Addition of Amino Acid Units to a Peptide Nucleic Acid Oligomer
• one or more amino acid units is added to the growing peptide nucleic acid oligomer of Example 13.
• the amine terminated peptide nucleic acid of Example 13 is extended with one or more amino acid units utilizing using an iteration of a standard solid phase Merrifield peptide synthesis condition for each added amino acid.
• the oligomer can be terminated with the amino acid or a further chain of peptide amino acid units added to the chimeric compound by further iterations of Example 13.
• Example 13 The resin from Example 13, 14 or 15 is swollen in di ⁇ chloromethane (200 mL) and to this is added tetrabutylammonium fluoride in THF (1.0 M, 1.0 mL) and the suspension stirred for 8 hours. The resin is then washed with dichloromethane containing 0.1% tetrabutyl ammonium chloride (10x25 mL) , 5 times with dichloromethane (25 mL) . The resin is suspended in dioxane (200 mL) and IN NaOH (20 mL) is added and the suspension stirred for 12 hours. The resin is washed with 5 times dioxane containing 0.5% IN HCI.
• the filtrates are pooled and evaporated to give the oligomeric product.
• the oligomer product with the side chain protecting groups is further deprotected by treatment with trifluoroacetic acid cresol (7/1 v/v) for 2 hours then diluted with diethyl ether and the precipitate collected to give the crude fully deprotected library.
• the solution is diluted with 500 mL of diethyl ether and filtered to remove triethylamine hydrochloride, then it is washed with water, followed by saturated sodium bicarbonate solution, dried (MgS0 4 ) , filtered, and evaporated to an oil.
• This oil is purified by crystallization to give a colorless solid.
• the solution is diluted with 500 mL of diethyl ether and filtered to remove triethylamine hydrochloride, then it is washed with water, followed by saturated sodium bicarbonate solution, dried (MgS0 4 ) , filtered, and evaporated to an oil.
• This oil is purified by crystallization to give a colorless solid.
• MBHA polystyrene beads (2.0 g, 1.0 mmol/gm loading, 1% crosslinked) is swelled in dichloroethane (150 mL) and to this is added triethyl amine (1.0 g, 10 mmol) and bromoacetyl bromide (2.0 g, 10 mmol) .
• the reaction mixture is stirred for 18 hours then filtered and washed 10 times with 100 mL of dichloromethane, then two times with diethyl ether, and is dried at low vacuum at 40 °C for 18 hours.
• the free flowing resin powder is used as is and can be checked for extent conversion by gel phase 13 C-NMR as per Epton, Ibid. .
• Bromoacetamido-MBHA resin ( 2 . 0 g, 1 . 0 mmol/gm loading) is swollen in dioxane (200 mL) and to this is added 1 - [2 - (thymin-1-yl ) acetyl] -2- (tetramethyl-1 , 2 -disilylethylene) - 1 , 2 -ethylenediamine ( 10 mmol ) , and a 2 . 0 M THF solution ( 5 mL) of lithio-tetramethylpiperidine. The suspension is stirred for 8 hours.
• the resin is then washed with dioxane (10x25 mL) , then two times with diethyl ether, and is dried at low vacuum at 40 °C for 18 hours.
• the free flowing resin powder is used as is and can be checked for extent conversion by gel phase 13 C- NMR as per Epton, Ibid. .
• the resin from Example 23 is suspended in dichloro ⁇ methane (100 mL) and 2.0 M tetrabutylammonium fluoride/THF (10 mL) is added and the reaction is stirred for 4 hours. The suspension is stirred for 8 hours. The resin is then washed with dichloromethane (10x25 mL) , then two times with diethyl ether, and is dried at low vacuum at 40 °C for 18 hours. The free flowing resin powder is used as is.
• the resin from Example 24 is swollen in dioxane (200 mL) and treated as per Example 22 to added a bromoacetyl moiety to the peptide nucleic acid on the resin.
• a bromoacetamido unit to the first peptide nucleic acid unit
• 1- (2- [thyminyl-1-yl] acetyl) -2- (tetramethyl-1 , 2- disilylethylene) -1,2-ethylenediamine (10 mmol) is added, and a 2.0 M THF solution (10 mL) of lithio-tetramethylpiperidine. The suspension is stirred for 8 hours.
• the resin is then washed with dioxane (10x25 mL) , then two times with diethyl ether, and is dried at low vacuum at 40 °C for 18 hours.
• the free flowing resin powder is used as is and can be checked for extent conversion by gel phase 13 C-NMR as per Epton, Ibid . . EXAMPLE 26
• the resin from Example 25 is suspended in dichloro- methane (100 mL) and 2.0 M tetrabutylammonium fluoride/THF (10 mL) ' is added and the reaction is stirred for 4 hours. The suspension is stirred for 8 hours. The resin is then washed with dichloromethane (10x25 mL) , then two times with diethyl ether, and is dried at low vacuum at 40 °C for 18 hours. The free flowing resin powder is used as is.
• the resin from Example 24 is swollen in dioxane (200 mL) treated as per example 22 to add a bromoacetyl moiety to the peptide nucleic acid oligomer on the resin and to this is added 1- (2- [thyminyl-1-yl] acetyl) -2- (tetramethyl-1, 2-disilyl- ethylene) -1, 2-ethylenediamine;l- ⁇ 2- [2-amino-N2- (benzyloxycar ⁇ bonyl) -N6- (benzyloxy)purin-9-yl] acetyl ⁇ -2- (tetramethyl-1,2-di ⁇ silylethylene) -1,2-ethylenediamine;1- ⁇ 2- [N4- (benzyloxycarbon ⁇ yl) cytosin-1-yl] acetyl ⁇ - 2 - (tetramethyl-1, 2-disilylethylene) - 1,2-ethylenediamine; andl- ⁇ 2- [N6
• the resin from Example 24 is swollen in dioxane (200 mL) treated as per example 22 to add a bromoacetyl moiety to the peptide nucleic acid oligomer on the resin. Then the resin is divided into four equal portions. Each portion is independently swollen in dichloroethane (50 mL) . To each portion of the swollen resin is added a 2.0 M THF solution (10 mL) of lithio-tetramethylpiperidine and one of the blocked nucleobase acetyl blocked 1, 2-diethylenediamines (.5 mmol) , i.e.
• the suspension is stirred for 8 hours.
• the resin is then washed with dioxane (10x25 mL) , then two times with diethyl ether, and is dried at low vacuum at 40 °C for 18 hours.
• the individual portions of the resin are recombined together.
• Example 27 The resins from Example 27 are deblocked as per the procedure of Example 26.
• a further known nucleobase is added utilizing the procedures of Example 25 followed by the procedure of Example 26.
• a further random nucleobase is added utilizing either the procedure of Example 27a followed by the procedure of Examples 26 or via the procedure of Example 27b followed by the procedure of Example 26. The required number of iterations of the combinations of procedures is effected to complete the oligomer of the desired length.
• Example 28 a peptide is prepared using standard solid phase Merrifield peptide synthesis building the peptide from carboxyl end toward the amine end.
• the amine terminated peptide is then extended with peptide nucleic acid units utilizing the procedures of Example 22 coupled with Examples 23 or 25 to either added nucleobases at fixed positions or, using Example 22 coupled with the combinatorial techniques of Example 27a or 27b, to added random nucleobases at any particular position.
• Example 26 After addition of the peptide nucleic acid unit, its terminal amine is deprotected via the procedure of Example 26.
• one or more amino acid units is added to the growing peptide nucleic acid oligomer.
• the amine terminated peptide nucleic acid of Example 26 is extended with one or more amino acid units utilizing using an iteration of a standard solid phase Merrifield peptide synthesis condition for each added amino acid.
• the oligomer can be terminated with the amino acid or a further chain of peptide amino acid units added to the chimeric compound by further iterations of Example 28.
• MBHA resin (2.0 g, 1.0 mmol/gm loading) is swollen in dichloromethane (200 mL) and to this is added 1- [2 - (thymin- 1-yl) carbonylmethyl] -3-oxo-morpholine and the suspension stirred for 8 hours. The resin is then washed with dichloro- methane (10x25 mL) , then two times with diethyl ether, and is dried at low vacuum at 40 °C for 18 hours. The free flowing resin powder is used as is and can be checked for extent conversion by gel phase 13 C-NMR as per Epton, Ibid. .
• Example 36 The resin from Example 36 is swollen in dioxane (200 mL) and to this is added triphenylphosphine (10 mmol) , diethyl- azodicarboxylate (10 mmol) , and bis (t-butoxycarbonyl) imide (10 mmol) .
• the suspension is heated to 60 °C and stirred for 12 hours. This suspension is filtered, washed with dioxane (5x100 mL) , and resuspended in dichloromethane (200 mL) .
• Example 37 The resin from Example 37 is swollen in dichloro ⁇ methane (200 mL) and to this is added a 1- [2- (nucleobase) - carbonylmethyl] -3-oxo-morpholine synthon (either 1- [2- (thymin- 1 -yl ) carbonylmethyl ] -3-oxo-morpholine, l- ⁇ 2- [N4- (benzyloxycarbonyl) cytosin-1-yl] carbonylmethyl ⁇ -3-oxo-morpho ⁇ line, l- ⁇ 2- [2-amino-N2- (benzyloxycarbonyl) -N6- (benzyloxy)purin- 9-yl] carbonylmethyl ⁇ -3 -oxo-morpholine or l- ⁇ 2- [N6- (benzyloxycarbonyl ) adenin-9-yl] carbonylmethyl ⁇ - 3 -oxo- morpholine) and the suspension is stir
• the resin is then washed with dichloromethane (10x25 mL) , then two times with diethyl ether.
• the resin is re-swollen in dioxane (200 mL) and to this is added triphenylphosphine (10 mmol) , di- ethylazodicarboxylate (10 mmol) , andbis (t-butoxycarbonyl) imide (10 mmol) .
• the suspension is heated to 60 °C and stirred for 12 hours.
• This suspension is filtered, washed with dioxane (5x100 mL) , and resuspended in dichloromethane (200 mL) .
• trifluoroacetic acid (30 mmol) and the suspension is stirred for 6 hours, then filtered and the resin is washed 10 times with dichloromethane (100 mL) then two times with diethyl ether.
• the resin from Example 37 is swollen in dichloro ⁇ methane (200 mL) and to this is added a mixture of 1- [2- (thymin-1-yl) carbonylmethyl] -3-oxo-morpholine, l- ⁇ 2- [N4- (benzyloxycarbonyl) cytosin-1-yl] carbonylmethyl ⁇ -3-oxo-morpho- line, l- ⁇ 2- [2-amino-N2- (benzyloxycarbonyl) -N6- (benzyloxy)purin- 9-yl] carbonylmethyl ⁇ -3-oxo-morpholine or 1- ⁇ 2- [N6- (benzyloxy ⁇ carbonyl) adenin-9-yl] carbonylmethyl ⁇ -3-oxo-morpholine (equal molar amounts) and the suspension is stirred for 8 hours.
• the resin from Example 37 is divided into four equal portions. Each portion is independently swollen in dichloro ⁇ ethane (50 mL) . To each portion of the swollen resin is added one of the blocked nucleobases synthons 1- [2- (thymin-1-yl) car ⁇ bonylmethyl] -3-oxo-morpholine, l- ⁇ 2- [N4- (benzyloxycarbonyl) - cytosin-1-yl] carbonylmethyl ⁇ -3-oxo-morpholine, l- ⁇ 2- [2-amino- N2 - (benzyloxycarbonyl) -N6- (benzyloxy) purin-9-yl] carbonyl ⁇ methyl ⁇ -3-oxo-morpholine or 1- ⁇ 2- [N6- (benzyloxycarbonyl) adenin- 9-yl] carbonylmethyl ⁇ -3-oxo-morpholine and the suspension is stirred for 8 hours.
• the suspensions are filtered, washed with dioxane (5x100 mL) , resuspended in dichloromethane (200 mL) and combined. To this is added trifluoroacetic acid (30 mmol) and the suspension is stirred for 6 hours, then filtered and the resin is washed 10 times with dichloromethane (100 mL) then two times with diethyl ether.
• the resins from Examples 38 or 39 are treated as per the procedure of Example 37 to convert the terminal hydroxyl moieties to terminal amine moieties.
• a further known nucleobase is added utilizing the procedures of Example 36 followed by the procedure of Example 37.
• a further random nucleobase is added utilizing either the procedure of Example 39a followed by the procedure of Example 36 or via the procedure of Example 39b followed by the procedure of Example 36. The required number of iterations of the combinations of procedures is effected to complete the oligomer of the desired length.
• a peptide is prepared using standard solid phase Merrifield peptide synthesis building the peptide from carboxyl end toward the amine end.
• the amine terminated peptide is then extended with peptide nucleic acid units utilizing the procedures of Example 37 coupled with Example 38 to added nucleobases at fixed positions or, using the combinatorial techniques of Example 39a or 39b coupled with the procedure of Example 36, to added random nucleobases at any particular position.
• one or more amino acid units is added to the growing peptide nucleic acid oligomer.
• the amine terminated peptide nucleic acid is extended with one or more amino acid units utilizing an iteration of a standard solid phase Merrifield peptide synthesis conditions for each amino acid added.
• the oligomer can be terminated with the amino acid or a further chain of peptide amino acid units added to the chimeric compound by further iterations of Example 40.
• the resin from Example 40 is dried by blowing argon across it for 15 minutes. It is washed twice with 3 ml portions of TFA for 2 minutes. The following reagents are added in order: 0.333 ml of m-cresol, 1.0 ml of dimethyl sulfide, and 1.83 ml of TFA. While the flask is shaking 0.167 ml of trifluoromethane sulfonic acid (TFMSA) is added dropwise. This mixture is shaken for 1 hour. At the end of that time the resin is drained and washed twice with 3 ml portions of TFA and four 3 ml portions of ethyl ether.
• TFMSA trifluoromethane sulfonic acid
• the deprotected PNA attached to the resin is dried with flowing argon.
• the following reagents are added in order: m-cresol 0.417 ml, TFA 3.33 ml and TFMSA 0.417 ml added dropwise with shaking. After 1 hour, the solution is drained into 25 ml of ether, and the resin washed with a single 3 ml portion of TFA.
• the acidic ether solution is concentrated to an oil, then diluted with 5 ml of water and extracted with 10 ml of ether until clear.
• PNA backbone oligomers are synthesized using the standard peptide nucleic acid chemistry. Each PNA residue (2 mmol each), N- [2- (thymin-1-yl) acetyl] -N- [2- (t-butyloxy ⁇ carbonyl) -2-ethylamino] glycine; N- ⁇ 2- [N4- (benzyloxycarbonyl) - cytosin-1-yl] acetyl ⁇ -N- [2- (t-butyloxycarbonyl) -2-ethylamino- [glycine; N- ⁇ 2- [N4- (benzyloxycarbonyl) adenin-9-yl] acetyl ⁇ -N- [2- (t-butyloxycarbonyl) -2-ethylamino] glycine; and N- ⁇ 2-[N2-[N2-[N2-[N2-[N2-[N2-[N2-[N2-[N2-[N2-[N2-
• the coupling is done in DMF/pyridine (2 mL) using TBTU (500 mol%) , diisopropylethylamme (1000 mol%) and the incoming PNA monomer (400 mol%) . Then, the aliquots of the residue-solid support are separately washed with DMF, followed by dichloromethane (each wash is 2x10 mL) . The separate aliquots are combined and thoroughly mixed by suspension and agitation in dichloromethane, then filtered, dried under vacuo and realiquoted into 4 subtractions.
• each residue pool or aliquot is deprotected with TFA (2x2 mL for 5 min) , then it is coupled again, mixed and realiquoted as described above. This is continued until the amino-terminal fixed position designated X is coupled, X-N-N-N-S, after which the pools are kept separate.
• the resin is cleaved by the procedure described in Stewart and Young, Solid Phase Peptide Synthesis (1984) . After removing the TFA/TFMSA mixture from the beads and precipitating the library from diethyl ether, the solid residue is worked up in the standard fashion to give separately the library pools with one fixed position each. These pools, one for every type of X residue, are assayed for activity. The most active residue is kept fixed
• A-X-N-N-S A-X-N-N-S.
• the synthesis procedure is the same as the first round. Coupling, mixing and realiquoting is continued until after the fixed position designated X is coupled. At this point aliquots are kept separate. The final residue, A, is coupled to each portion. By keeping the pools separate, one obtains pools which are unique at one fixed position. This synthesis technique is continued until the entire sequence is determined.
• PNA backbone oligomers are be synthesized using the standard peptide chemistry.
• Each PNA residue, (2 mmol each) N- [2- (thymin-1-yl) acetyl] -N- [2- (t-butyloxycarbonyl) -2-ethyl ⁇ amino] glycine; N- ⁇ 2- [N4- (benzyloxycarbonyl) cytosin-1-yl] acet ⁇ yl ⁇ -N- [2- (t-butyloxycarbonyl) -2-ethylamino] glycine; N- ⁇ 2- [N 4 - (benzyloxycarbonyl) adenin-9-yl] acetyl ⁇ -N- [2- (t-butyloxycarbon ⁇ yl) -2-ethylamino]glycine; N- ⁇ 2- [N2- (benzyloxycarbonyl)
• the coupling is done in DMF/pyridine (2 mL) using TBTU (500 mol% calculated for total carboxylic acid content) , diisopropylethylamme (1000 mol%) and the incoming PNA monomer (400 mol% of each monomer) . Then, the residue-solid support are washed with DMF, followed by dichloromethane (each wash is 2x10 mL) . For the next position, the pool was deprotected with TFA (2x2 mL for 5 min) , then it is coupled again as described above. This is continued until the amino-terminal fixed position designated X is coupled.
• the resin is divided into four pools and each is coupled with a single peptide nucleic acid monomer, X-N-N-N-S, after which the pools are kept separate.
• the resin pools are cleaved by the procedure described in Stewart and Young, Solid Phase Peptide Synthesis (1984) .
• the solid residue is worked up in the standard fashion to give separately the library pools with one fixed position each.
• PNA backbone oligomers are be synthesized using the standard peptide chemistry.
• Each PNA residue, (2 mmol each) N- [2- (thymin-1-yl) acetyl] -N- [2- (t-butyloxycarbonyl) -2-ethyl ⁇ amino] glycine; N- ⁇ 2- [N4- (benzyloxycarbonyl) cytosin-1-yl] acet ⁇ yl ⁇ -N- [2- (t-butyloxycarbonyl) -2-ethylamino] glycine; N- ⁇ 2- [N 4 - (benzyloxycarbonyl) adenin-9-yl] acetyl ⁇ -N- [2- (t-butyloxycarbon ⁇ yl) -2-ethylamino]glycine; N- ⁇ 2- [N 4 - (benzyloxycarbonyl) adenin-9-yl] acetyl ⁇ -N- [2-
• the coupling is done in DMF/pyridine (2 mL) using TBTU (500 mol% calculated for total carboxylic acid content) , diisopropylethylamine (1000 mol%) ' and the incoming PNA monomer (400 mol% of each monomer) . Then, the residue-solid support are washed with DMF, followed by dichloromethane (each wash is 2x10 mL) . For the next position, the pool was deprotected with TFA (2x2 mL for 5 min) , then it is coupled again as described above.
• the resin is separated into 4 separate but equal aliquots, the deprotected with TFA (2x2 mL for 5 min) , washed as above and reacted separately with solutions of N- (t-butyloxycarbonyl) amino acid, i.e. glycine, phenylalanine, O-benzylaspartic acid, and N- benzyloxycarbonyl lysine, each activated by dissolving 2 mmol of amino acid in DMF/pyridine (1 mL) containing 3 mmol TBTU and 500 mmol DIPEA. After allowing the reactions to proceed for 15 minutes the resin is washed thoroughly as described above. The aliquots are kept separate.
• N- (t-butyloxycarbonyl) amino acid i.e. glycine, phenylalanine, O-benzylaspartic acid, and N- benzyloxycarbonyl lysine
• the oil is dissloved in 100 mL of dichloromethane and dry HCI gas is bubbled through the solution for 30 minutes and the reaction stirred for 1 hour.
• the reaction is diluted with 200 mL of cold diethyl ether and allowed to stand at -5 °C for 12 hours.
• the colorless solid formed is collected and stored protected from moisture.
• the resin from Example 52 is swollen in dichloroethane (200 mL) and to this is added N- trimethylsilylethoxycarbonyl-1, 2-diaminoethane hydrochloride (2.4g, 10 mmol) , [0- (7-azabenzotriazol-l-yl) -1, 1, 3 , 3-tetra- methyluronium hexafluorophosphate (3.8g, 10 mmol) , and triethylamine (2.0g, 20 mmol) .
• reaction mixture is heated to 35 °C for 18 hours, then cooled and the resin is washed 5 times with dichoromethane (50 mL) , then 3 times with diethyl ether (100 mL) , and is dried at low vacuum at 40 °C for 18 hours .
• the resin from Example 53 is swollen in dichloromethane (200 mL) and to this is added tetrabutylammonium fluoride in THF (1.0 M, 1.0 mL) and the suspension stirred for 8 hours. The resin is then washed with dichloromethane containing 0.1% tetrabutyl ammonium chloride (10 X 25 mL) , 5 times with dichloromethane (25mL) , and 3 times with diethyl ether (lOOmL) , and is dried at low vacuum at 40 °C for 18 hours. The free flowing resin powder is used as is and can be checked for extent conversion by gel phase 13 C-NMR according to E. Girard.
• the resin from Example 54 is swollen in dichloroethane (20 OmL) and to this is added t-butyl bromoacetate (10 mmol) and triethylamine (2,0g, 20 mmol) .
• the reaction mixture is heated to 30 °C for 18 hours, then cooled and the resin is washed 5 times with dichoromethane (50 mL) , then 3 times with diethyl ether (100 mL) , and is dried at low vacuum at 40 °C for 18 hours.
• the free flowing resin powder is used as is.
• the resin from Example 55 is swollen in dichloroethane (200 mL) and to this is added 1-carboxymethyl thymine (2.0g, 10 mmol) and triethylamine (2,0g, 20mmol) .
• the reaction mixture is heated to 40 °C for 18 hours, then cooled and the resin is washed 5 times with dichoromethane (50 mL) , then 3 times with diethyl ether (100 mL) , and is dried at low vacuum at 40 °C for 18 hours.
• the free flowing resin powder is used as is.
• the resin from Example 57 is swollen in dichloromethane (200 mL) and to this is added a uronium salt (lOmmol) , diisopropylethyl amine (25mmol) , and N- trimethylsilylethoxycarbonyl-1, 2-diaminoethane hydrochloride (2.4g, 10 mmol) .
• the reaction is stirred at room temperature for 4 hours then filtered and washed 5 times with dichloromethane (50 mL) , then 3 times with diethyl ether (100 mL) and is dried at low vacuum at 40 °C for 18 hours.
• the free flowing powder is used as is.
• PNA monomers are added via the sub-monomer approach to a growing PNA oligomer by repeating Examples 54 through 58.
• the resin is suspended in trifluoromethanesulfonic/trifluoroacetic acid m-cresol (1/8/1, 30 mL) and allowed to stand for 3 hours.
• the solution is separated from the spent resin by filtration.
• the acids are diluted with diethyl ether (200 mL) and the precipitated solid collected, washed with ether and dried to give the crude PNA produ ' ct. This crude PNA product is purified using standard techniques to obtain the pure PNA oligomer.
• (2-chlorobenzyloxycarbonyl) -lysine resin was washed with 5 ml of dichloromethane (DCM) , for 15 minutes.
• the DCM was drained and 5 ml of dimethyl formamide (DMF) was added and the flask shaken for another 15 minutes. Again the DMF was drained and the resin then washed with 3 ml of a 1:1 solution of DCM:DMF for 1 minute. This was repeated an additional 2 times.
• the t-butoxy carbonyl group (Boc) was removed from the ⁇ - amine of the lysine in the following fashion.
• the resin was treated with 1 ml of DCM and 3 ml of a 5% m-cresol in trifluoroacetic acid, (TFA) , for 2 minutes; this is repeated three times, draining the solution after each cleavage.
• the resin is then washed with 3 ml of 1:1 DCM:DMF for 1 minute repeated 3 times, and 3 ml of pyridine (pyr) , for 1 minute repeated 4 times.
• the beads are clear and colorless, with the solution taking on a light orange color for a negative test.
• Any free amines were then capped using 1- (benzyloxycarbonyl) - 3 -methy1 imidazol ium trifluoromethane sulfonate (Rapoport's Reagent) .
• Rapoport's Reagent 1- (benzyloxycarbonyl) - 3 -methy1 imidazol ium trifluoromethane sulfonate
• Example 60 The procedure of Example 60 was repeated coupling first the thymine PNA monomer exactly described in Example 60. The second coupling was performed as above, substituting of cytosine PNA monomer (101 mg, 200 ⁇ moles) . The coupling with glycine, cleavage, and analysis were repeated exactly as found in Example 60.
• Example 60 The procedure of Example 60 was followed except that guanine PNA monomer (109 mg, 200 ⁇ moles) was substituted for the adenine PNA monomer.
• guanine PNA monomer 109 mg, 200 ⁇ moles
• Example 60 The procedure of Example 60 was followed except that thymine PNA monomer (109 mg, 200 ⁇ moles) was substituted for the adenine PNA monomer.
• Example 65 After coupling the portion containing the Asp-XX-Lys- Resin from Example 65 was divided into four portions of equal size weighing 47 mg. These pools were deprotected using two 3 ml " portions of TFA:m-cresol . The resins were washed and coupled using the procedure found in Example 47 using the following quantities in four vials, each containing one of the PNA monomers: Adenine 55 mgl04 ⁇ moles
• Step 1 m-cresol0.66 ml
• Step 2 m-cresolO .835 ml

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• 1994
  • 1994-02-23 US US08/200,742 patent/US5539083A/en not_active Expired - Lifetime
• 1995
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• 1996
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• 1998
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