Pigments of Fungi. XLVI. New Dimeric Dihydroanthracenones of the Flavomannin Type from an Australian Toadstool of the Genus Dermocybe

Abstract

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 (6) 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 (ω-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.