Microbial hydroxylation of 13-ethyl-17 beta-hydroxy-18,19-dinor-17 alpha-pregn-4-en-20-yn-3-one.

ABSTRACT

The microbial transformation of the racemic mixture of 13-ethyl-17 beta-hydroxy-18,19-dinor-17 alpha-pregn-4-en-20-yn-3-one (1) was investigated. Rhizopus nigricans (AS 3.2050), R. arrhizus (AS 3.4523), Aspergillus niger (AS 3.2744), A. ochraceus (AS 3.1408), and Curvularia lunata (NRRL 4381) transformed 1 into its 10 beta-hydroxy derivative (2) as a major metabolite. Biotransformation of 1 by Aspergillus ochraceus AS 3.1408 afforded 7 beta-hydroxy derivative (3) as the only product.