Biotransformation XLV. Transformations of 4-ene-3-oxo steroids in Fusarium culmorum culture.

The course of transformations of five 4-ene-3-oxo steroids with varying substituents at C-17 i.e.: 4-androsten-3-one, androstenedione, testosterone, progesterone and 17alpha-hydroxyprogesterone in Fusarium culmorum culture was investigated. All the substrates were hydroxylated either at 12beta and 15alpha, or at 15alpha or 6beta positions, depending on the structure of the substrate. The main product of 4-androsten-3-one transformation was 12beta,15alpha-diol. A similar 12beta,15alpha-diol was obtained from progesterone, but the main product of transformation of this substrate was 15alpha-hydroxyprogesterone. The products of hydroxylation at 6beta or 15alpha positions were isolated from 17alpha-hydroxyprogesterone. The androstenedione and testosterone transformation mixtures contained the same products (6beta-hydroxyandrostenedione, 6beta-hydroxytestosterone, 15alpha-hydroxyandrostenedione and 15alpha-hydroxytestosterone), but the quantities of 6beta- and 15alpha-alcohols varied, depending on the substrate used. During transformations of these two substrates, apart from hydroxylation, ketone-alcohol interconversion at C-17 occurred.