Scytalone dehydratase; part of the gene cluster that mediates the biosynthesis of dihydroxynaphthalene melanin, a bluish-green pigment and a structural component of the conidial wall (PubMed:9571787). Within the pathway, catalyzes the dehydration of scytalone as well as of vermelone (PubMed:9571787, PubMed:9466791, PubMed:9466792, PubMed:9539706, PubMed:10320327, PubMed:10386945, PubMed:10386946, PubMed:10694394, PubMed:10913266, PubMed:10636235, PubMed:11790103, PubMed:12413868, PubMed:15056895). Is also able to dehydrate the alternate substrate 2,3-dihydro-2,5-dihydroxy-4H-benzopyran-4-one (DDBO) to 5-hydroxy-4H-1-benzopyran-4-one (HBO) (PubMed:9466791, PubMed:9466792, PubMed:10320327, PubMed:10386945, PubMed:11790103). scytalone = 1,3,8-trihydroxynaphthalene + H2O (N-phenoxypropyl)-carboxamides such as carpropamid and derivatives of norephedrine act as inhibitors of scytalone dehydratase activity. Pigment biosynthesis; melanin biosynthesis. Homotrimer (PubMed:7866745). Each subunit contains an active site, located in the central part of the hydrophobic core of the monomer, which functions independently (PubMed:7866745). Expression is induced in the stationary phase, when melanin synthesis occurs (PubMed:9571787). Expression is specifically induced during appressorium formation (PubMed:15378734). Belongs to the scytalone dehydratase family.