From the fruits of Bulbine abyssinica three new dimeric anthracene derivatives, (P)-8,9,10 ,80 -tetrahydroxy-3,30 -dimethyl[10,70 bianthracene]-1,4,90 ,100 -tetraone (trivial name abyquinone A), (10R)-1,4,8,10 ,80 -pentahydroxy-3,30 -dimethyl-[10,70 -bianthracene]- 9,90 ,100 (10H)-trione (trivial name abyquinone B), and (10R)-30 ,40 -dihydro-1,4,8,30 ,80 ,90 -hexahydroxy-3,30 -dimethyl-[10,70 -bianthracene]- 9,10 (10H,20 H)-dione (trivial name abyquinone C) were isolated. Despite their structural differences, these three compounds are connected to each other by the apparently biomimetic conversion of abyquinone C (a preanthraquinonylanthrone with two stereogenic centers) into B (an anthraquinonylanthrone with one stereogenic center) and finally into A (an axially chiral bianthraquinone) under mild conditions, involving a highly efficient center-to-axis chirality transfer. In addition, the known anthraquinones islandicin and chrysophanol were identified. The structures were determined on the basis of spectroscopical evidences, chemical transformations, and quantum chemical CD calculations.