Microbial hydroxylation of steroids. 11. Hydroxylation of A -nor-, B -homo-Δ 1 -, and Δ 1 -testosterone acetates by Rhizopus arrhizus

The testosterone derivatives A-nortestosterone acetate and B-homo-Δ 1 -testosterone acetate have been incubated with Rhizopusarrhizus, a fungus which hydroxylates testosterone at the C-6β and C-11 α positions. These modes of hydroxylation were also observed for the A-nor steroid. The B-homo steroid, however, was oxidized at C-2β and concurrently hydroxylated at C-6β and C-7aβ (but not at C-11) by R. arrhizus. Δ 1 steroids of conventional skeleton were hydroxylated at C-11α by R. arrhizus; in addition, Δ 1 -androstenedione was epoxidized at the 1,2β position. No C-6 hydroxylation of conventional Δ 1,4 -3-ketosteroids was observed.