Transformation of structurally diverse steroidal analogues by the fungus Corynespora cassiicola CBS 161.60 results in generation of 8β-monohydroxylated metabolites with evidence in favour of 8β-hydroxylation through inverted binding in the 9α-hydroxyla

► 8β-Hydroxylation occurs through capsized binding in a 9α-hydroxylase. ► 17α-Oxygen functionality required for 8β-hydroxylation of progestogens. ► First single crystal X-ray structural determination of 8β,17α-dihydroxyprogesterone. ► 17α-Hydroxyprogesterone hydroxylation indicates C-3 ketone has two binding sites.