Bianthraquinones from Cassia siamea

The isolation of two bianthraquinones, 1,1',3,8,8'-pentahydroxy-3',6-dimeth yl[2,2'-bianthracene]-9,9',10,10'-tetrone and 7-chloro-1,1',6,8,8'-pentahyd roxy-3,3'-dimethyl[2,2'-bianthracene]-9,9',10,10'-tetrone, from the root ba rk of Cassia siamea is reported. The structures were established by analysi s of spectroscopic data and 7-chloro-1,1',6,8,8'-pentahydroxy-3,3'-dimethyl [2,2'-bianthracene]-9,9',10,10'-tetrone was determined on the direct compar ison with synthetic compound. (C) 2001 Elsevier Science Ltd. All rights res erved.