Anthraquinone pigments from Cassia javanica seeds

From the seeds of Cassia javanica chrysophanol, physcion, 1,5-dihydroxy 4,7-dimethoxy 2-methyl anthraquinone 3-O-alpha-L(-) rhamnopyranoside and 1,3,6,7,8-pentahydroxy-4-methoxy 2-methyl anthraquinone have been isolated. Chrysophanol and physcion are commonly occurring anthraquinones but 1,5-dihydroxy 4,7-dimethoxy 2-methyl anthraquinone 3-O-alpha-L(-) rhamnopyranoside and 1,3,6,7,8-pentahydroxy 4-methoxy 2-methyl anthraquinone have not been reported earlier; and in the present communication the structural studies of these are reported. The structures of the two compounds have been arrived at by their colour reactions, spectral data and degradation studies.