Austrocolorins A1 and B1: atropisomeric 10,10'-linked dihydroanthracenones from an Australian Dermocybe sp.

The atropisomeric austrocolorins A(1) (7) and B(1) (8), new members of the rare tricolorin class of 10,10'-coupled dihydroanthracenones, are isolated from an indigenous Australian toadstool belonging to the subgenus Dermocybe of Cortinarius, and their structure and absolute central and axial configuration is deduced from the spectroscopic data, and confirmed by chemical degradation and chiral HPLC analysis.