IE45020B1 - Tetrapeptides and pentapeptides - Google Patents

Description

The present invention relates co tetra- and penta-peptides. The present invention provides compounds of formula I, A-B-Gly-Q-E I wherein A is a residue of formula wherein Rj is hydrogen or alkyl of 1 to 4 carbon atoms, Rg is hydrogen or, together with Rj, forms an ethylene bridge, and R3 is hydrogen, or an R^CO- group, wherein R4 is methyl or a saturated or unsaturated branched or unbranched alkyl residue of 2 to 17 carbon atoms, phenyl or phenyl-alkyl of 7 to 12 carbon atoms in which the phenyl radical and the phenyl residue - 2 43USU of the phenylalkyl radical may be mono- or disubstituted with fluorine, chlorine or bromine, alkyl of 1 to 4 carbon atoms or alkoxy of 1 to 4 carbon atoms, whereby the RjO group is in a position meta- or para- to the t1 — CH, — C — CO — residue, 2 I NHZ Z is hydrogen, alkyl of 1 to 5 carbon atoms, alkenyl of 3 to 5 carbon atoms, cyclopropylmethyl, cyclobutylmethyl, or R^CO, wherein is as previously defined, B is -(D)-Ala-, Q is a residue of formula — N—CH—CO — i t Rs CH2 wherein R5 is methyl, E is i) CH3 - S(0) - CH2 - CH2 - CH CO -X wherein X is / —or-OR' R and each of R', R and R' independently signifies hydrogen or alkyl of 1 to 5 carbon atoms or - 3 ii) a residue of formula — N — CH,— CH,OR. wherei n Rg is hydrogen or R^CO-, wherein R^ is as previously defined, Rj, is hydrogen or methyl, and Rg is a radical of formula (CH2)s- CHg —CHg wherein s is 0 or 1, wherein the radicals A and Q possess either the L or DL configuration and the radical E possesses the L, D or DL configuration.

When Rj is alkyl, this is preferably methyl.

Rj preferably is hydrogen or, together with Rg, forms an ethylene bridge. Rg is preferably hydrogen.

RgO is preferably in a position para- to the R, — CHg — —CO - residue. Ληζ Z is preferably hydrogen. X is preferably N \R„ , especially-NHg R7 is preferably hydrogen, Rg is preferably hydrogen, s is especially 1.

The residue defined for E preferably has the L-configuration.

In one group of compounds, R^ is alkyl of 1 to 17 carbon atoms, preferably to 12 carbon atoms, more preferably from 1 to 6 carbon atoms, for example, methyl, - 4 4 5 0 30 ethyl, n-propyl and n-butyl. When R^ is alkyl of two or more carbon atoms, this moiety may be unsaturated. When R^ is alkyl of three or more carbon atoms, the moiety may be branched and optionally unsaturated.

When R^ is phenyl or phenylalkyl of 7 to 12 carbon atoms, e.g. tolyl and benzyl, the phenyl residue may be mono- or disubstituted with fluorine, chlorine or bromine. The phenyl residue may also be mono- or disubstituted with alkyl of 1 to 4 carbon atoms or alkoxy of 1 to 4 carbon atoms.

In a second group of compounds, Z is hydrogen, alkyl of 1 to 5 carbon atoms, alkenyl of 3 to 5 carbon atoms, cyclopropylmethyl or cyclobutylmethyl.

In a third group of compounds, Z is R^CO, wherein R4 is as previously defined.

In a fourth group of compounds, E is -methioninol - sulphoxide -X, wherein X is - NR'R' as previously defined.

In another group of compounds, X is -OR' as previously defined.

In a fifth group of compounds, E as previously defined under ii) is N - CH wherein Rg, R? and Rg are as previously defined.

A peptide of formula-1 may be obtained by methods which are conventional in the art of peptide synthesis.

Accordingly, the present invention provides a process for the production of a compound of formula I which comprises a) removing at least one protective group from a protected peptide having the sequence given in formula I, or b) linking together by an amide bond two units, each of which contains at least one amino and/or E and which is in protected or unprotected form, the amino acid units being such that the amino acid sequence given in formula I is obtained, and, then, if necessary, effecting process variant a), or c) converting a group A and/or E of an unprotected or protected peptide into - 5 4 SO 30 another group A and/or E having the definition previously indicated, and, if necessary, effecting process variant a).

The above methods are known in peptide chemistry and may be effected in manner analogous to the processes described in the following Examples or as described in our Patent Specification No. 45019..

Insofar as the production of the starting materials is not particularly described, these compounds are known or may be produced and purified in accordance with known methods. These compounds may also be produced in a manner analogous to the processes described in the following Examples.

The compounds may exist in salt, including acid addition salt, forms or in the form of complexes, for-example, complexes with metals.

Suitable acids for acid addition salt formation are acetic acid, trifluoroacetic acid and hydrochloric acid.

Suitable metals for complex formation include calcium (II), magnesium (II), aluminium (III), cobalt (II), (III), and especially zinc (II).

In the following Examples, all temperatures are indicated in degrees / Celsius.

The abbreviations, commonly used in the art, are as follows:Ac = acetyl Boc = tert.-butyloxycarbonyl Me = methyl TFA = trifluoroacetic acid AcTyr = N-acetyltyrosyl Ata (6-OH) = 2-amino-6-hydroxy-2-tetralin-carboxylic acid Ata (7-OH) = 2-amino-7-hydroxy-2-tetralin-carboxylic acid MePhe = N-methylphenyl alanyl MeTyr = N-methyltyrosyl m-Tyr = m-tyrosyl Tyr (Me) = 0-methyltyrosyl decomp = decomposition temperature. - 6 45020 EXAMPLE 1.

H-Tyr-(D)-Ala-Gly-MePhe-(L)-methioninolsulphoxide.

A mixture of 0.18 g of Boc - Tyr -(D) - Ala - Gly -MePhe -(L) methi oni nosulphite in 2 ml of CHgCJ and 0.33 mol of cooled anisole and 10 ml of 98% (w/v) TFA added. The mixture is left to stand for 30 minutes at room temperature, the volume reduced under vacuum and the concentrate added dropwise, with stirring, to 130 ml of diethyl ether.

The precipitated product is centrifuged off. The residue is recrystallised twice from diethyl ether, dissolved in water and lyophilised, whereupon the title compound is obtained.

- -A-Γε a 2.05 in 95% (w/v) acetic acid?.

The Boc - Tyr - (D) - Ala - Gly - MePhe - (L) - methioninolsulphoxide used as starting material may be prepared as follows :a) Boc-MePhe-OH. 3.6 g of H - MePhe - OH.are dissolved in a mixture of tert.-butanol, ml of 10% (w/v) aqueous KHCOg solution and 5 ml of 4N sodium hydroxide. 8 ml of di-tert.-butyl carbonate are added and the mixture stirred for 2 days at room temperature. The reaction mixture is diluted with ca. 100 ml of water and extracted with diethyl ether. The aqueous phase is acidified, with stirring to pH 2. The precipitated product is extracted with acetic acid, the extract washed with water and dried over NagSO^. The liquid is evaporated and the product crystallised from diethyl ether/petroleum ether to yield Boc - MePhe - OH.

M.P. 87°C. = -65°C (c = 1 in methanol). b) Boc-MePhe-(L)-methioninol. 3.1 g of Boc-MePhe-OH are dissolved in 30 ml of tetrahydrofuran, cooled to -20°, and 1.45 ml of N-ethylmorpholine are added with stirring followed by 1.45 ml of chloroformic acid iso-butyl ester and the mixture stirred for a further minutes at -20°. A cold solution of 1.80 g of (L)-methioninol in 8 ml of - 7 «5020 tetrahydrofuran is added, the mixture left to stand for 2 hours at a temperature of from -5° to 0° and then stirred for 2 hours at room temperature. The reaction mixture is diluted with ca. 350 ml of acetic acid and washed repeatedly with water, IN citric acid, 10% (w/v) KHCOg and 30% (w/v) NaCl solution. The organic phase is dried over Na2S0 and evaporated, whereupon Boc-MePhe-L-methioninol is obtained as an amorphous product. Λ«_7020 = -54° (c = 1.24 in methanol). c) Η-MePhe-(L)-methioninol.trifluoroacetate.

To a solution of 4.3 g of Boc-MePhe-(L)-methioninol in 20 ml of CH2C12, ml of CH3-S-CH-CH3 and 0.2 ml of HS-CH2-CH2-0H are added 40 ml of 98% (w/v) TFA at 0°. The reaction mixture is left stand for 1-1/2 hours and thereafter the volume is reduced in vacuo to 5-10 ml and precipitated twice from diethyl ether/ petroleum ether. The oily product is dried under high vacuum, whereupon H-MePhe-Lmethioninol.tri fluoroacetate is obtained as an amorphous product. /"«_7q20 = +3.2° (c = 0.98 in methanol). d) Boc-Tyr-(D)-Ala-Gly-MePhe-(L)-methioninol. 1.23 g of Boc - Tyr - (D) - Ala - Gly - OH is dissolved in 30 ml of THF and cooled to 15°. 0.38 ml of N-ethylmorpholine are added with stirring followed up by 0.39 ml of chloroformic acid iso-butyl ester and stirring continued for 10 minutes. A cold solution of 14 g of H - MePhe - (L) - methioninol-TFA and 0.45 ml of Nethylmorpholine in 12 ml of TFA are added with stirring at -15°. The mixture is stirred for 20 hours at 0°, diluted with 250 ml of acetic acid and washed repeatedly with water, IN citric acid, 10% (w/v) NaCl solution. The liquid is dried over Na2$04 and evaporated. The residue is purified chromatographically on silicagel using a mixture of methanol/CH2C12/5O% (w/v) acetic acid, whereupon the title compound is obtained, decomp. 16O°C. /o<_7dZ0 = -50° (c = 1.8 in DMF). e) 0.32 g of Boc - Tyr -(D) - Ala - Gly - MePhe - (L) - methioninol are dissolved in 4 ml of 90% (w/v) acetic acid and 0.07 ml of 10 M H202 is added. The - 8 45030 mixture is left to 'stand for 3 hours at room temperature and reduced in volume under vacuum. The residue is purified chromatograph!cally on silicagel using a mixture of CHgClg/methanol/SOJi (w/v) acetic acid, whereby the amorphous starting material is obtained. ΓοιΊ^ = -36° (c = 1.74 in dimethylformamide).

The following compounds can be prepared in manner anaTogous to those illustrated in the foregoing Example, using appropriate starting materials-in approximately equivalent amounts.

All the amino residues, wi.th the exception of glycyl, as well as the 10 amino alcohols possess the L-configuration unless otherwise stated. An amino alcohol is indicated as belonging to the L-series when the -CHg-OH is in the position occupied by the et-COOH group in the amino acid concerned. - 9 45020 Compounds of Formula I : H-Tyr-(D)-Ala-Gly-Q-E The compounds-of formula I exhibit pharmacological activity. In particular, the compounds' exhibit analgesic activity, e.g. in the Tail Flick Test in mice, in the Randall-Selitto Test in the rat and in the Shock Titration Test in the rhesus monkey. Additionally, the compounds inhibit spontaneous motor activity in mice, causing hypothermia, sedation and inducing catalepsy, and exhibit properties similar to those of an anti-psychotic agent e.g. a neuroleptic.

The compounds are therefore indicated for use as analgesic and antipsychotic agents. For these uses a preferred daily dose is from 30 to 300 mg, conveniently administered in unit dosage form containing from 7 to 150 mg, or in sustained release form.

The compounds may be administered in pharmaceutically acceptable salt form, including acid addition salt forms, or in the form of complexes. Such forms exhibit the same order of activity as the free base form and are readily prepared in conventional manner. Representative acids for acid addition salt forms include organic acids such as trifluoroacetic acid and mineral acids such as hydrochloric acid. Suitable metals for complex formation include zinc (II).

The present invention also comprises a pharmaceutical composition comprising a compound of formula I, in free base form or in the form of a pharmaceutically acceptable salt or complex, in association with a pharmaceutically acceptable salt carrier or diluent. Such compositions may be in the form of, for example, a solution or a capsule.

Claims (1)

1.CLAIMS 1. A process for the production of a compound of formula I, A —B—Gly —Q—E (I) wherein 2. A process for the production of a compound of formula I, as defined in Claim 1, as hereinbefore described with reference to the Examples. 3. A compound of formula I, as defined in Claim 1, whenever produced by a process as claimed in Claim 1 or 2. 4. A compound of formula I, as defined in Claim 1. 5. A compound of Claim 4, wherein R 3 is hydrogen. 5 A is a residue of formula C - CO NHZ wherein Rj is hydrogen or alkyl of 1 to 4 carbon atoms, Rg is hydrogen or, together with Rj, forms an ethylene bridge, and 6. A compound of Claim 4 or 5, wherein E is a radical (ii). 7. A compound of Claim 4, 5 or 6 wherein Z is hydrogen, alkyl of 1 to 5 carbon atoms, alkenyl of 3 to 5 carbon atoms, cyclopropylmethyl or cyclobutylmethyl. 8. H - Tyr - (D) - Ala - Gly -Q-E, wherein Q and E are as defined in Claim 1. 10. H - Tyr - (D) - Ala - Gly - MePhe - (L) - S - methyleysteinolsulphoxide. 11. H - Tyr - (D) - Ala '- Gly - MePhe - (L) - methioninamidesulphoxide. 10 Rg is hydrogen, or an R^CO- group, wherein R 4 is methyl or a saturated or unsaturated branched or unbranched alkyl residue of 2 to 17 carbon atoms, phenyl or phenylalkyl of 7 to 12 carbon atoms in which the phenyl radical and the phenyl residue of the phenylalkyl 12. H - Tyr(Me) - (D) - Ala - Gly - MePhe - (L) - methioninolsulphoxide. - 12 10020 Q is a residue of formula — N — CH — CO — r 5 ch 2 wherei n R g is methyl, E is i) CHg — S(0) -ch 2 CH 2 - CH wherein X is R' or-OR 1 and each of R‘, R‘ 1 , and R 1 independently signifies hydrogen or alkyl of 1 to 5 carbon atoms, or ii) a residue of formula — N - CH — CH„OR, II 26 R 7 R 8 13. N - cyclobutylmethyl - Tyr - (D) - Ala - Gly - MePhe - (L) - methioninolsulphoxide. - 13 4 5 0 2 0 R 7 is hydrogen or methyl, and Rg is -(ch 2 ) s -ch 2 -s-ch 3 wherein s is 0 or 1, wherein the radicals A and Q possess either the L or DL configuration and the radical E possesses the L-, D- or DL configuration which comprises a) removing at least one protective group from a protected peptide having the sequence given in formula I, or b) linking together by an amide bond two units, each of which contains at least one amino acid and/or E and which is in protected or unprotected form, the amino acid units being such that the amino acid sequence given in formula I is obtained, and then if necessary, effecting process variant a), or c) converting a group A and/or E of an unprotected or protected peptide into another group A and/or E, and, -if necessary, effecting process variant a). 14. H - (DL) - Ata(7 - OH) - (D) - Ala - Gly - MePhe - (L) - methioninolsulphoxide. - 14 450 30 Π. Η - (DL) - Ata(6 - OH) - (D) - Ala -Gly - MePhe - (L) - methioninolsulphoxide. 15. MeTyr - (D) - Ala - Gly - MePhe - (L) - methioninolsulphoxide. 15 wherein Rg is hydrogen or R^CO-, wherein is as previously defined, 15 radical may be mono- or disubstituted with fluorine, chlorine or bromine, alkyl of 1 to 4 carbon atoms or alkoxy of 1 to 4 carbon atoms, whereby the RgO group is in a position meta- or para- to the f 1 — CHg— C — CO - residue, NHZ Z is hydrogen, alkyl of 1 to 5 carbon atoms, alkenyl of 3 to 5 carbon atoms, 16. H - (DL) - m - Tyr - (D) - Ala - Gly - MePhe - (L) - methioninolsulphoxide. 17. AcTyr - (D) - Ala - Gly - MePhe - (L) - methioninolsulphoxide. 18. A compound of Claim 4, wherein the radical A and Q possess the Lconfiguration, and the radical E possesses the L or D configuration. 19. H - Tyr - (D) - Ala - Gly - MePhe - (L) - methioninolsulphoxide. 20. A compound according to any one of Claims 3 to 17 in complex form. 20 cyclopropylmethyl, cyelobutylmethyl, or R^CO, wherein is as previously defi ned, B is -(0}-Ala, 21. A compound according to Claim 18 or 19 in complex form. 22. A compound according to any one of Claims 3 to 17 in salt form. 23. A compound according to Claim 18 or 19 in salt form. 24. A pharmaceutical composition comprising a compound according to any one of Claims 3 to 17, in free base form or in the form of a pharmaceutically acceptable salt or complex, in association with a pharmaceutically acceptable diluent or carrier. 25. A pharmaceutical composition comprising a compound according to Claim 18 or 19, in free base form or in the form of a pharmaceutically acceptable salt or complex, in association with a pharmaceutically acceptable diluent or carrier.