Biotransformation of ent-13-epi- and ent-manoyl oxides by Rhizopus nigricans cultures

Abstract

Microbial transformation of ent-6α,18-diacetoxy-16-hydroxy-13-epi-manoyl oxide (3) has been carried out with Rhizopus nigricans cultures, which converted the substrate (3) into its 20-hydroxy-, ent-3β-hydroxy-, and (14S)-spiro derivatives. R. nigricans transformed ent-6α,18-diacetoxy-16-hydroxymanoyl oxide (5) into its ent-11β-hydroxy and (14R)-spiro derivatives. The metabolite structures have been determined spectroscopically and sometimes by chemical correlation as well.