Figure 2.

Paraherquamide biosynthetic pathway. The pathway includes nonribosomal peptide synthetase (NRPS) PhqB, prenyltransferase PhqI, intramolecular Diels-Alderase PhqE, and flavin-dependent monooxygenase PhqK. A putative prenyltransferase and oxidative enzyme are proposed to be involved in the formation of the pyran and dioxepin rings. PhqB and PhqE require nicotinamide adenine dinucleotide phosphate (NADPH) cofactor for catalysis, while PhqK requires flavin adenine dinucleotide (FAD) and the reduced nicotinamide adenine dinucleotide (NADH) cofactor. PhqI prenylates the indole C2 position with a prenyl group provided by dimethylallyl pyrophosphate (DMAPP).