Discovery of a Fungal Multicopper Oxidase That Catalyzes the Regioselective Coupling of a Tricyclic Naphthopyranone To Produce Atropisomers

Atropisomeric dinapinones A1 and A2 (DPA1 and DPA2) were isolated from a culture of Talaromyces pinophilus FKI‐3864. Monapinone coupling enzyme (MCE), which dimerizes naphthopyranone monapinone A (MPA), was purified from a cell‐free extract of T. pinophilus FKI‐3864. MCE regioselectively dimerizes MPA at the 8,8′‐positions to synthesize the atropisomers DPA1 and DPA2 in a ratio of approximately 1:2.5 without a cofactor. The optimal pH value and...