Scytalols A, B, C, and D and other modulators of melanin biosynthesis from Scytalidium sp. 36-93

Abstract

From submerged cultures of Scytalidium sp. 36-93, ten metabolites were isolated due to their effects on dihydroxynaphthalene (DHN) or DOPA melanin biosynthesis. Four of the compounds, scytalols A, B, C, and D, are new secondary metabolites, the structures of which were determined by spectroscopy, while the other compounds are known. Scytalols A and D are selective inhibitors of DHN melanin biosynthesis and exhibit no antifungal or cytotoxic activities. Nectriapyrone, 6-methoxymellein and 4-chloro-6-methoxymellein stimulated the formation of DOPA melanin in B16-F1 melanoma cells in the absence of melanin-stimulating hormone.