NADPH dehydrogenase; part of the gene cluster that mediates the biosynthesis of aflavarin, a bicoumarin that exhibits anti-insectan activity against the fungivorous beetle C.hemipterus (PubMed:26209694, Ref.2). A + H(+) + NADPH = AH2 + NADP(+) Secondary metabolite biosynthesis. Expression is induced by the developmental and secondary metabolism regulator veA (PubMed:26209694). Fails to produce aflavarin (PubMed:26209694). Belongs to the NADH:flavin oxidoreductase/NADH oxidase family. NamA subfamily.