Cytochrome P450 monooxygenase; part of the gene cluster that mediates the biosynthesis of heptelidic acid (HA), a sesquiterpene lactone that acts as an inhibitor of glyceraldehyde-3-phosphatedehydrogenase (GAPDH) and a growth inhibitor of the salt-tolerant lactic acid bacteria in soy sauce brewing. Secondary metabolite biosynthesis. Abolishes the production of heptelidic acid. Belongs to the cytochrome P450 family.