Patent GB-1382255-A (GB)
Title: Method for the production of aminopenicillins
IPC: C07D499/66
Filed: 1971-12-29
Abstract: 1382255 Preparing aminopenicillins TAKEDA YAKUHIN KOGYO KK 29 Dec 1971 [25 Dec 1970] 60406/72 Heading C2C [Also in Division C3] Aminopenicillins having the Formula (I) wherein R is an optionally substituted 6- membered cyclic hydrocarbon residue are prepared by reacting an amino acid derivative of Formula (II) wherein R is as above and A is alkoxy, carboxyalkylthio, amino or carboxylalkylamino, with 6-aminopenicillanic acid (6-APA) in aqueous medium in the presence of a microorganism or enzymic preparation therefrom, which is capable of producing an aminopenicillin of Formula (I) from a compound of Formula (II) and 6-APA but is substantially incapable of producing penicillin G from phenylacetic acid and 6-APA and belongs to the genus Mycoplana, Protoaminobacter, Acetobacter, Pseudomonas, Aeromonas or Xanthomonas. The group R may be phenyl, cyclohexyl, cyclohexenyl or cyclohexadienyl and may be substituted by hydroxy, halogen, alkyl, alkoxy, carboxy, mercapto, cyano, nitro, sulpho, amino or sulphamino groups. The preferred compounds (II) are the methyl esters (i.e. A is methoxy) of the amino acid. The 6-APA may be used in the form of a salt (e.g. Na, K or hydrochloride salt), or may be in admixture with, e.g. phenylacetic or phenoxyacetic acid as an unpurified product of a penicillin acylase treatment of penicillin G or V. Suitable micro-organisms are Mycoplana dimorpha IFO 13213 ; Protoaminobacter alboflavus IFO 13221; Acetobacter sp. IFO 13209, 13210 and 13211; Acetobacter cerinus IFO 3263, dioxyacetonicus IFO 3271, pasteurianum IFO 3223, Suboxydans IFO 3172, turbidans IFO 3225 and xylinum IFO 3228; Aeromonas sp. IFO 13212; Xanthomonas sp. IFO 13215; Xanthomonas citri IFP 3781, oryzae IFO 3995 and pruni IFO 3780; and Pseudomonas sp. IFO 13214, Pseudomonas aeruginosa IFO 3755 and polycolor IFO 3918. The micro-organism is isolated from a natural or known culture by selecting those organisms which are resistant to α-aminobenzylpenicillin and which can propagate by assimilating as a sole carbon source phenylglycine methyl ester, phenylglycine thioglycol ester or N-(phenylglycyl) glycine (i.e. compounds of Formula II). From strains thus selected are chosen those organisms which can produce compounds (I) from 6-APA and a compound of Formula II but are incapable of producing penicillin G from 6-APA and phenylacetic acid, for use in the inventive process. The process is effected in aqueous medium which may contain up to 40% by volume of methanol, ethanol or acetone, at pH 4 to 8 and 10‹-50‹ C. The enzymic activity may be provided by a whole culture of the micro-organism, a washed cell suspension or culture filtrate thereof, a cell extract obtained by lysing the cells, or a suitably purified enzyme preparation. The aminopenicillin may be recovered from the reaction mixture by a conventional procedure such as chromatography. DL- 1-Cyclohexenylglycine is prepared by treating 1-cyclohexene-1-aldehyde with sodium cyanide and ammonium chloride, and hydrolyzing the resulting aminonitrile. The said compound is converted to its DL-methyl ester with thionyl chloride and methanol. The DL-methyl ester is stereospecifically hydrolyzed with α-chymotrypsin to remove the L-form and leave D-ICyclohexenylglycine methyl ester.