Abstract
Through the microbiological transformation of 3β, 14, 21-trihydroxy-14β-pregnan-20-one (III) and 4, 5-dehydrodigitoxigenone (IV) by Absidia orchidis, several kinds of products were isolated, and the structure and configuration of three hydroxylated products, one from III and two from IV, were clarified ; 1β, 3β, 14, 21-tetrahydroxy-14β-pregnan-20-one (V), 7β, 12β-dihydroxy-4, 5-dehydrodigitoxigenone (VIII), and 7β-hydroxy-4, 5-dehydrodigitoxigenone (IX). Based on these experimental results, the relationships between the structure of substrate and the positions to be hydroxylated in the microbiological transformation of cardiac aglycone derivatives by A.orchidis were discussed.
