Microbial transformation of dydrogesterone by Gibberella fujikuroi

Microbial transformation of dydrogesterone (9b,10a-pregna-4,6-diene-3,20-dione) (1) on fermentation with Gibberella fujikuroi yielded 20R-hydroxy-9b,10a-pregna-4,6-diene-3-one (2), 17b-hydroxy-9b,10a-androsta-4,6-diene-3-one (3) and 9b,10a-androsta-4,6-diene-3,17-dione (4). Their structures were deduced on the basis of modern spectroscopic techniques. This is the first report of their production by using Gibberella fujikuroi.