Two new anthraquinone dimers from the fruit bodies of Bulgaria inquinans.

Two new dimeric anthraquinone derivatives, bulgareone A(1) and bulgareone B(2), were isolated from the fruit bodies of Bulgaria inquinans. Their structures were elucidated on the basis of extensive spectroscopic analysis. The in vitro cytotoxic activity of compounds 1 and 2 was assayed. They displayed inhibitive activities against human cancer cell lines HL60 and K562.