Dioxygenase; part of the gene cluster that mediates the biosynthesis of anditomin, a fungal meroterpenoid (PubMed:25216349). The first step of the pathway is the synthesis of 3,5-dimethylorsellinic acid (DMOA) by the polyketide synthase andM (PubMed:25216349). DMOA is then converted to the phthalide compound 5,7-dihydroxy-4,6-dimethylphthalide (DHDMP) by the cytochrome P450 monooxygenase andK, which is further prenylated by the prenyltransferase andD to yield farnesyl-DHDMP (PubMed:25216349). Further epoxidation by the FAD-dependent monooxygenase andE leads to epoxyfarnesyl-DHDMP (PubMed:25216349). The next step involves the terpene cyclase andB that converts epoxyfarnesyl-DHDMP into preandiloid A through opening of the epoxide ring followed by the cyclization of the farnesyl moiety (PubMed:25216349). Preandiloid A is in turn oxidized at the C-3 hydroxyl group to yield preandiloid B by the dehydrogenase andC (PubMed:25216349). The dioxygenase andA is solely responsible for the dehydrogenation of preandiloid B leading to the enone preandiloid C, as well as for the intriguing structural rearrangement to generate the bicyclo[2.2.2]octane core, transforming preandiloid C into andiconin (PubMed:25216349). FAD-binding monooxygenase andJ then produces andilesin D which is reduced by dehydrogenase andI to yield andilesin A (PubMed:25216349). Action of acetyltransferase andG followed by a spontaneous acetate elimination leads then to andilesin B, which is in turn substrate of the short chain dehydrogenase andH to yield andilesin C (PubMed:25216349). Finally, the dioxygenase andF catalyzes the transformation of andilesin C to anditomin (PubMed:25216349). Secondary metabolite biosynthesis; terpenoid biosynthesis. Homodimer. Impairs the synthesis of anditomin but accumulates preandiloid B (PubMed:25216349). Belongs to the PhyH family.