卡那霉素B的酶—化学修饰

ENZYMATIC-CHEMICAL MODIFICATION OF KANAMYCIN B

用酶—化学修饰的方法,对卡那霉素B的C_3~′位进行化学结构改造。利用耐药菌E.coliK.12 ML1629产生的钝化酶选择性地使卡那霉素B的C_3~′位羟基磷酸化,再用化学方法,将卡那霉素B-3~′—磷酸酯转化为3′—氯代—3′—去氧卡那霉素B,进而合成3′去氧卡那霉素B,即妥布拉霉素。

A promising method for selective modification of Kanamycin B at C-3'position by enzymatic and chemical process was reported. Kanamycin B was phosphorylated by the enzyme from Kanamycin B resistant mutant E. coli K12 ML1629 to its 3'-phosphate(1). Reaction of(1)with Me3SiCl and Ph3P in a sealed tube gave, after hydrolysis, 3'-chloro-3'-deoxy kanamycin B(2)which was hydrogenated with Raney nickel to yield 3'-deoxy kanamycin B(3). The fermentation for E. coli K12 ML1629, optimal pH of the enzyme reaction, selection of buffer, concentration of ATP and reaction duration were investigated. Also the chlorination of (1) and selection of catalyst in hydrogenolysis were explored. All compounds described herein were separated and purified by column and preparative thin layer chromatography on ion exchange resin, Amberlite IRC50, Amberlite CG 50,and C-107,respectiyely,and were confirmed by MS,NMR,IR spectraan delementary analysis. Antimicrobial activity showed that 3'-deoxykanamycin B, i. e. Tobramycin was more effective than kanamycin B against the kanamycin resistant mutant E. coli K12 ML1629.