Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K31/00—Medicinal preparations containing organic active ingredients
  • A61K31/66—Phosphorus compounds
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P25/00—Drugs for disorders of the nervous system
  • A61P25/04—Centrally acting analgesics, e.g. opioids
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P25/00—Drugs for disorders of the nervous system
  • A61P25/08—Antiepileptics; Anticonvulsants
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P25/00—Drugs for disorders of the nervous system
  • A61P25/28—Drugs for disorders of the nervous system for treating neurodegenerative disorders of the central nervous system, e.g. nootropic agents, cognition enhancers, drugs for treating Alzheimer's disease or other forms of dementia
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F9/00—Compounds containing elements of Groups 5 or 15 of the Periodic Table
  • C07F9/02—Phosphorus compounds
  • C07F9/28—Phosphorus compounds with one or more P—C bonds
  • C07F9/38—Phosphonic acids [RP(=O)(OH)2]; Thiophosphonic acids ; [RP(=X1)(X2H)2(X1, X2 are each independently O, S or Se)]
  • C07F9/3804—Phosphonic acids [RP(=O)(OH)2]; Thiophosphonic acids ; [RP(=X1)(X2H)2(X1, X2 are each independently O, S or Se)] not used, see subgroups
  • C07F9/383—Cycloaliphatic acids
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F9/00—Compounds containing elements of Groups 5 or 15 of the Periodic Table
  • C07F9/02—Phosphorus compounds
  • C07F9/28—Phosphorus compounds with one or more P—C bonds
  • C07F9/38—Phosphonic acids [RP(=O)(OH)2]; Thiophosphonic acids ; [RP(=X1)(X2H)2(X1, X2 are each independently O, S or Se)]
  • C07F9/40—Esters thereof
  • C07F9/4003—Esters thereof the acid moiety containing a substituent or a structure which is considered as characteristic
  • C07F9/4018—Esters of cycloaliphatic acids
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F9/00—Compounds containing elements of Groups 5 or 15 of the Periodic Table
  • C07F9/02—Phosphorus compounds
  • C07F9/547—Heterocyclic compounds, e.g. containing phosphorus as a ring hetero atom
  • C07F9/645—Heterocyclic compounds, e.g. containing phosphorus as a ring hetero atom having two nitrogen atoms as the only ring hetero atoms
  • C07F9/6503—Five-membered rings
  • C07F9/6506—Five-membered rings having the nitrogen atoms in positions 1 and 3

Definitions

• the present invention relates to one of the eight isomers of 2- amino-4,5-(1 ,2-cyclohexyl)-7-phosphonoheptanoic acid, a compound which is an excitatory amino acid (EAA) neurotransmitter receptor antagonist useful as an anticonvulsant, analgesic, cognition enhancer, and neuroprotectant.
• EAA excitatory amino acid
• the invented isomer is unexpectedly more potent in in vitro receptor binding assays and in in vivo efficacy studies.
• ACPA 2-amino-4,5-(1 ,2-cyclohexyl)-7- phosphonoheptanoic acid
• the presently invented compound that is active as an excitatory amino acid receptor antagonist is the 2R, 4R, 5S isomer of ACPA that is substantially free from the other ACPA isomers. Substantially free is defined to mean at least about 95% pure.
• the starting material for preparation of the novel compound of the invention is 1 R, 2S- Methyl (hydrogen)-1,2-c/s-cyclohex-4-ene diacetate Z *
• This compound is prepared from the known meso diester via enantioselective enzymatic hydrolysis utilizing the enzyme porcine pancreas lipase.
• the use of this enzyme to obtain the chiral product £ is known in the literature.
• diborane is used to selectively reduce the carboxylic acid group to the corresponding hydroxyethyl side chain
• Bromide VII is reacted with the sodium salt of diethylphosphite in tetrahydrofuran to obtain phosphonate VIII.
• Enzymatic hydrolysis of VIII with the enzyme D-hydantoinase obtained from cells of Agrobacterium radiobacter results in conversion to carbamoyl acid IX.
• the free amino acid X obtained from chemical hydrolysis of IX is then deprotected with iodotrimethylsilane to obtain the compound of the invention, 2R, 4R, 5S ACPA.
• This method begins with the hydrolysis of diester 3. using pig liver esterase (PLE), a reaction known to yield the 1S, 2R half-ester in 97% enantiomeric excess.
• PLE pig liver esterase
• Selective reduction of the carboxylate ester with lithium triethylborohydride afforded the enantiomerically pure (-)-1 R, 2S lactone 6.
• the optical rotation of this lactone was identical to that reported in the literature. I.J. Jakovac, __i __l., J. Am. Chem. Soc. (1982) 104, 4659.
• compositions of the invented isomer are formed with strong moderately strong organic or inorganic acids or bases by known methods.
• Exemplary of the salts included in this invention are maleate, fumarate, lactate, oxalate, methanesulfonate, ethavesulfonate, bezenesulfonate, tartrate, citrate, hydrochloride, hydrobromide, sulfate, phosphate, quinate, and nitrate salts.
• compositions comprising the invented isomer of ACPA and suitable carriers in pharmaceutical dosage forms such as capsules, tablets, injectable preparations, ointments, creams, topical reservoirs such as transdermal patches, and suppositories.
• Solid or liquid carriers can be used.
• Solid carriers include starch, lactose, calcium, sulfate, dehydrate, terra alba, sucrose, talc, gelatin, agar, pectin, acacia, magnesium stearate, and stearic acid.
• Liquid carriers include syrup, peanut oil, olive oil, saline and water.
• Suppositories are prepared from standard bases such as polyethylene glycol and cocoa butter.
• the method of this invention of antagonizing excitatory amino acid receptors comprises administering internally to a subject expected to be benefited thereby an effective amount of the invented ACPA isomer.
• Doses of this isomer included in the invented methods and pharmaceutical compositions are an efficacious, nontoxic quantity selected from the range of 0.01 to 100 mg/kg of active compound, preferably 0.1 to 50 mg/kg. Persons skilled in the art using routine clinical testing are able to determine optimum doses.
• the desired dose is administered to a subject from 1 to 6 or more times daily, orally, rectally, parenterally, or topically.
• Example 3 The Table 1 data show that the cis isomer A is at least 25-fold more potent than the next most potent isomer in producing these in __i__Q effects.
• Example 4 The procedure for determining the binding potencies reported in Table 2 is described in Example 4.
• the Table 2 data show that the cis isomer A is approximately 8-fold more potent than cis isomer C, the next most potent isomer.
• the following examples are illustrative of preparation and testing of the invented isomer of ACPA. In these Examples, the compounds designated by roman and arabic numerals are shown in Schemes I and II, above, respectively.
• ester III (2.50g; ⁇ .Ommol) in 40ml of toluene was cooled to -78°C and treated with diisobutylaluminum hydride (6.1 ml of a 1.5M solution; 9.2mmol). The mixture was stirred for 2 hours at -78°C and then poured into 30ml of an ice-cold saturated aqueous solution of sodium-potassium tartrate. The layers were separated and the aqueous layer was washed with 2 x 20ml of ethyl acetate. The combined organic layers were washed with brine, dried (MgSO4) and freed of solvent. The residue was purified on a silica gel column eluting with 1-5% ethyl acetate in hexane to obtain 1.63g (72%) of the product as a light oil.
• IR ' (CDCl3): 3440, 3155, 2934, 2263, 1772, 1725, 1468, 1383, 121 1 , 1095 cm “ 1 .
• Hydantoin VIII was converted to the carbamoyl derivative by reaction with the enzyme D-hydantoinase.
• Carbamoyl IX was obtained in yields of ca. 60% as a white crystalline solid after recrystallization from water. X-ray diffraction analysis of this compound verified that it was of the 2R, AR, 5S configuration.
• Electron impact mass spectrum m/e 379 (MH + ), 364, 336, 335, 291 , 263.
• Carbamoyl acid IX is chemically cleaved to the free amino acid X _. r using nitrous acid as described in the literature cited above. Cleavage of the phosphonate esters of X to give XI is achieved using either bromo- or ⁇ odotrimethylsilane.
• Compound X (1mmoI) in methylene chloride/acetonitrile (10ml) is treated with the halotrimethylsila ⁇ e (10mmol). This mixture is stirred for 16 hours at room temperature Q and then evaporated to dryness. The residue is partitioned between water and chloroform. The aqueous layer is made neutral (pH 7) and concentrated in vacuo; the product can be purified by ion exchange on a Dowex 50W-Xb column.
• Compound XI is obtained as the hydrate.
• the ether portions were washed with brine, dried ( gSO4) and freed of solvent.
• the product was purified on a silica gel column eluting with 5% ethyl acetate in hexane to obtain the product as a clear oil, 550mg (70%).
• Tetraethyl methylenebisphosphonate (4.32g; 14.99mmol) was added dropwise as a tetrahydrofuran solution (10ml) to a stirred suspension of sodium hydride (660mg of a 60% oil dispersion; 16.5mmol) in THF (15ml). After gas evolution had ceased the mixture was stirred at room temperature for 2 hours and then cooled to -78°C.
• This impure material was hydrogenated in the presence of 5% palladium on carbon (200mg) in 30ml of ethanol under 50psi pressure of hydrogen for 4 hours. The mixture was filtered through Celite and freed of solvent. Purification of the crude residue on a silica gel-60 column, eluting with 5% methanol in ethyl acetate, delivered a total of 260mg (8.7% overall) of a pure mixture of Ha and 11b.
• esters 11a and 11 b (260mg total) was dissolved in pH 7.4 phosphate buffer and stirred at room temperature.
• Subtilisin A Novo Biolabs, 30mg was added and the mixture was stirred overnight.
• the pH was brought back to 7.4 by the dropwise addition of 0.2M NaOH.
• the mixture was diluted with water, transferred to a separatory funnel, and extracted with 3x75ml of ethyl acetate. The ethyl acetate portions were dried (MgSO4) and freed of solvent to deliver 10Omg of 11 a.
• the aqeous phase was made acidic (pH 1) with 1N HCI and extracted with 3x75mf of ethyl acetate. After drying and removal of the solvent 50mg of acid 12 was obtained.
• Anticonvulsant studies The potency of the isomers of APCA to inhibit NMDA-induced seizures was evaluated using male CF-1 mice. All drugs were dissolved in isotonic saline and the pH adjusted to neutrality using NaOH. The test compounds were injected intracerebroventricularly (i.c.v.) in a final volume of 5 ml. N-Methyl-D-aspartate (250mg/kg of body weight) was dissolved in saline (1% v/w of body weight) and injected intraperitoneally (i.p.) 15 minutes following the administration of the test agent. Mice were observed for 30 minutes following the administration of the chemical convulsant and scored as present or absent. NMDA-induced seizures were defined as presence of tonic/clonic activity accompanied by hindlimb extension and death.
• Rotorod Animals used for seizure studies were evaluated for motor impairment using the rotorod test. Before use all animals were tested for their ability to maintain equilibrium for 60 seconds on a 1-inch knurled bar rotating at a speed of 6 to 7 rpm. Each animal was given three separate trials. Animals performing the task in any of the three trials were used for further study.
• Animals were tested for impairment 10 minutes after i.c.v. administration of the test agent and 5 minutes before administration of the seizure-inducing agent. Each animal was tested on a maximum of three trials; completion of any one of the trials was screened as passing.
• membranes were thawed to room temperature and homogenized in 20 vol (w/v) of assay buffer.
• the homogenate was centrifuged (48,000 x g; 10min; 4°C), the supernatant decanted and the pellet resuspended as before. The procedure was repeated until the tissue had been washed 4 times to remove endogenous inhibitors.

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• 1991
  • 1991-11-20 ZA ZA919196A patent/ZA919196B/xx unknown
  • 1991-12-04 JP JP4502346A patent/JP2721933B2/ja not_active Expired - Lifetime
  • 1991-12-04 EP EP92901599A patent/EP0639197B1/en not_active Expired - Lifetime
  • 1991-12-04 AT AT92901599T patent/ATE142220T1/de not_active IP Right Cessation
  • 1991-12-04 DE DE69121920T patent/DE69121920T2/de not_active Expired - Fee Related
  • 1991-12-04 WO PCT/US1991/008834 patent/WO1992010099A1/en not_active Ceased
  • 1991-12-04 DK DK92901599.8T patent/DK0639197T3/da active
  • 1991-12-04 CA CA002097910A patent/CA2097910A1/en not_active Abandoned
  • 1991-12-04 ES ES92901599T patent/ES2094338T3/es not_active Expired - Lifetime
  • 1991-12-06 IE IE425691A patent/IE75735B1/en not_active IP Right Cessation
• 1996
  • 1996-12-04 GR GR960403296T patent/GR3021881T3/el unknown

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