Fermentative process for preparing antibiotics of the gentamicin class

Abstract

2-Hydroxygentamicins B, B.sub.1 and A.sub.3 and 2-hydroxy antibiotics JI-20A and JI-20B are prepared as fermentation products by culturing a nutrient medium containing carbohydrates, a source of assimilable nitrogen, essential salts and D-streptamine with a mutant of Micromonospora purpurea, and isolating the said fermentation products from the nutrient medium; the fermentation products are acylated with an ester of an .omega.-(N-benzyloxycarbonyl)amino-.alpha.-hydroxy-lower-alkanoic acid, after first blocking the 6'- and/or 2'-amine group with an amine-protecting group, followed by catalytic hydrogenolysis of the benzyloxycarbonyl group and removal of the amine-protecting groups to prepare the 1-N-(.omega.-amino-.alpha.-hydroxy-lower-alkanoyl) derivatives.

Dependencies are inferred from the claim text.