Sphaerolone and dihydrosphaerolone, two bisnaphthyl-pigments from the fungus Sphaeropsidales sp F-24 ' 707

Two new bisnaphthslene compounds, sphaerolone (1) and dihydrosphaerolone (2 ), together with 2-hydroxyjuglone (9), were isolated fi um the culture brot h of a Sphaeropsidales sp. (strain F-24'707) after inhibition of the regula r proceeding 1,8-dihydroxynayhthalene (DHN) biosynthesis with tricyclazole. The structures of 1 and 2 were established by detailed spectroscopic analy sis and present novel bisnaphthalenes. The biosynthetic origin of 1 and 2 a s dimerization products of 1,3,8-trihydroxynaphthalene, an intermediate of the DHN biosynthesis, is discussed. (C) 2000 Elsevier Science Ltd. Ail righ ts reserved.