Improving the monooxygenase activity and the regio- and stereoselectivity of terpenoid hydroxylation using ester directing groups

The monooxygenase enzyme CYP101B1, from Novosphingobium aromaticivorans DSM12444, binds norisoprenoids more tightly than monoterpenoids and oxidized these substrates with high regioselectivity. Ionols bound less tightly to CYP101B1 than ionones, but the levels of product formation remained high and the selectivity of oxidation was similar to that observed for the parent norisoprenoid. The structurally related sesquiterpene lactone (+)-sclareolide (9) was stereoselectively hydroxylated by CYP101B1 to (S)-(+)-3-hydroxysclareolide (9a). The turnover of monoterpenoid derivatives showed low levels of product formation and selectivity despite promising binding data. CYP101B1 catalyzed the selective oxidation of (1R)-(−)-nopol (14) and cis-jasmone (15), generating >90% (1R)-(−)-5-hydroxynopol (14a) and 4-hydroxy-cis-jasmone (15a), respectively. To develop strategies for the efficient and selective oxidation of monoterpenoid-based substrates using CYP101B1, we investigated the binding and catalytic properties of ...