Inhibitor and substrate activities of sesquiterpene olefins toward (+)-δ-cadinene-8-hydroxylase, a cytochrome P450 monooxygenase (CYP706B1)

The five tested sesquiterpenes were all inhibitory, with I50 concentrations in the order (−)-δ-cadinene < (−)-α-cubebene < (−)-α-muurolene < α-humulene < (−/+)-α-copaene. All except (−/+)-α-copaene were mono-hydroxylated by CYP706B1.