New Antihepatotoxic Naphtho-pyrone Glycosides from the Seeds of Cassia tora ¹

Abstract

Two new naphtho-pyrone glycosides, 9-[(β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl)oxy]-10-hydroxy-7-methoxy-3-methyl-1H-naphtho[2,3-c]pyran-1 -one (5) and 6-[(α-apiofuranosyl-(1→6)-O-β-D-glucopyrano-syl)oxy]-rubrofusarin (6), together with cassiaside (3) and rubrofusarin-6-β-gentiobioside (4) were isolated from the seeds of Cassia tora L. Their structures were elucidated on the basis of chemical and spectral data. The naphtho-γ-pyrone glycosides (3, 4, and 6) were found to have significant hepato-protective effects against galactosamine damage, which were higher than that of silybin from Silybum marianum.