Pigments of fungi. XLVI - New dimeric dihydroanthracenones of the flavomannin type from an Australian toadstool of the genus Dermocybe

cis, cis-4,4'-Dihydroxyflavomannin 6,6'-di-O-methyl ether A (4), 10,10'-dihydroxy-4,4'-dioxoflavomannin 6,6'-di-O-methyl ether A (B) and 4',10-dihydroxy-4-oxoanhydroflavomannin-9',10'-quinone 6,6'-di-O-methyl ether A (7), new coupled dihydroanthracenones, and bierythroglaucin (8), a novel dimeric anthraquinone, have been isolated along with emodin (9) and citreorosein (omega-hydroxyemodin) (10) from the purple-brown fruit bodies of the Australian Dermocybe sp. WAT 21566. The structures and relative stereochemistry of the new natural products (4) and (6)-(8) are deduced by spectroscopic and chemical methods.