Triptexanthosides A-E: Xanthone Glycosides from Aerial Parts of Tripterospermum japonicum.

From the aerial parts of Tripterospermum japonicum, five new xanthone glycosides, named triptexanthosides A-E, were isolated along with a known xanthone C-glucoside, mangiferin. Their structures were elucidated as 1, 2, 6, 8-tetrahydroxyxanthone (norswetianin) 1-O-β-D-glucopyranoside and 1-O-β-gentiobioside, and 1, 2, 8-trihydroxy-5, 6-dimethoxyxanthone 2-O-β-D-glucopyranoside, 2-O-β-primeveroside and 1-O-gentiobioside, respectively, from spectroscopic evidence and acid hydrolysis.