Pentaketide metabolites of Verticillium dahliae -Identification of (+) -scytalone as a natural precursor to melanin
Bell, A.; Stipanovic, R.; Puhalla, J.
Tetrahedron 2 (12) 1353-1356
ISSN/ISBN: 0040-4020 DOI: 10.1016/0040-4020(76)85009-0
Culture filtrates of the brown brm-1 mutant of Verticillium 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., UV, IR, NMR, MS) and chemical conversions. Related metabolites, flaviolin and cis-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.