Penta ketide metabolites of verticillium dahliae identification of dextro scytalone as a natural precursor to melanin
Bell, A.A.; Stipanovic, R.D.; Puhalla, J.E.
Tetrahedron 32(12): 1353-1356
ISSN/ISBN: 0040-4020 Accession: 006079125
Culture filtrates of the brown brm-1 mutant of V. dahliae Kleb. restored normal black pigment (melanin) synthesis when added to plate cultures of 10 albino mutants. The active metabolite was isolated and identified as (+)-scytalone [3,4-dihydro-3,6,8-trihydroxy-1(2H)naphthalenone] by physical characteristics (m.p. [melting point], UV, IR, NMR, MS [mass spectrometry]) and chemical conversions. Related metabolites, flaviolin and cis-4-hydroxyscytalone, were also isolated and identified. Flaviolin and its derivatives contribute to the reddish brown color of the brm-1 mutant. Scytalone may be a general intermediate of melanin biosynthesis in fungi.