STUDIES ON THE BIOSYNTHESIS OF CARBAPENEM ANTIBIOTICS

I. BIOSYNTHETIC SIGNIFICANCE OF THE OA-6129 GROUP OF CARBAPENEM COMPOUNDS AS THE DIRECT PRECURSORS FOR PS-5, EPITHIENAMYCINS A AND C AND MM 17880

Abstract

Based on the working hypothesis that the OA-6129 group of carbapenem compounds might be the direct precursors for PS-5, epithienamycins A and C and MM 17880, Streptomyces fulvoviridis A93317M9, a producer of PS-5, PS-6, PS-7, PS-8, epithienamycins A, B, Cand D, MM 17880, MM 13902 and MM 4550, was subjected to NTG-mutation to provide ablocked mutant numbered 1501 which was found to produce OA-6129A, OA-6129B₁, OA-6129B₂ and OA-6129C instead of PS-5, epithienamycins A and C and MM 17880, respectively. In a cell-free system, the parent strain demonstrated an ability to collvert OA-6129A to NS-5, whereas the mutant did not. The L-and D-amino acid acylases were also shown to depantothenylate the OA-6129 group of carbapenems.