Phenylethanoid and flavone glycosides from Ruellia tuberosa L.

A new phenylethanoid glycoside, isocassifolioside (8), and two new flavone glycosides, hispidulin 7-O-α-l-rhamnopyranosyl-(1′″ → 2″)-O-β-d-glucuronopyranoside (11) and pectolinaringenin 7-O-α-l-rhamnopyranosyl-(1′″ → 2″)-O-β-d-glucuronopyranoside (12) were isolated from the aerial portions of Ruellia tuberosa L., together with verbascoside (1), isoverbascoside (2), nuomioside (3), isonuomioside (4), forsythoside B (5), paucifloside (6), cassifolioside (7), hispidulin 7-O-β-d-glucuronopyranoside (9) and comanthoside B (10). The structure elucidations were based on analyses of chemical and spectroscopic data including 1D- and 2D-NMR. The isolated compounds 1–12 exhibited radical scavenging activity using ORAC assay.