Non-reducing polyketide synthase; part of the gene cluster that mediates the biosynthesis of the diterpenoid pyrones higginsianins A and B (PubMed:32286350). The first step of the pathway is the synthesis of the alpha-pyrone moiety by the polyketide synthase dpchA via condensation of one acetyl-CoA starter unit with 3 malonyl-CoA units and 2 methylations (Probable). The alpha-pyrone is then combined with geranylgeranyl pyrophosphate (GGPP) formed by the GGPP synthase dpchD through the action of the prenyltransferase dpchC to yield a linear alpha-pyrone diterpenoid (Probable). Subsequent steps in the diterpenoid pyrone biosynthetic pathway involve the decalin core formation, which is initiated by the epoxidation of the C10-C11 olefin by the FAD-dependent oxidoreductase dpchE, and is followed by a cyclization cascade catalyzed by the terpene cyclase dpchB (Probable). The short chain dehydrogenase/reductase dpchG then oxidizes the 8S hydroxy group to a ketone and the short chain dehydrogenase/reductase dpchH reduces the ketone to the 8R hydroxy group to yield higginsianin B (PubMed:32286350). Finally, the FAD-dependent oxidoreductase dpchF converts higginsianin B into higginsianin A (PubMed:32286350). Secondary metabolite biosynthesis; terpenoid biosynthesis. Multidomain protein; including a starter unit:ACP transacylase (SAT) that selects the starter unit; a ketosynthase (KS) that catalyzes repeated decarboxylative condensation to elongate the polyketide backbone; a malonyl-CoA:ACP transacylase (MAT) that selects and transfers the extender unit malonyl-CoA; a product template (PT) domain that controls the immediate cyclization regioselectivity of the reactive polyketide backbone; a methyltransferase (CMeT) domain responsible for methylations; and an acyl-carrier protein (ACP) that serves as the tether of the growing and completed polyketide via its phosphopantetheinyl arm. Diterpenoid pyrones display various biological activities and higginsianin A shows anti-HIV activity.