Phenylethanoid glycosides from Globularia trichosantha

Five phenylethanoid glycosides, crenatoside (= oraposide) (1), verbascoside (= acteoside) (2), trichosanthoside A (3), rossicaside A (4), and trichosanthoside B (5), were isolated from the aerial parts of Globularia trichosantha. Compounds 3 and 5 are new natural compounds, and their structures were established as 3, 4-dihydroxy-beta-phenylethoxy-O-beta-D-xylopyranosyl-(1-->4)alpha-L-rhamnopyranosyl-(1-->3)-4-O-caffeoyl-beta-D-glucopyranoside and 3,4-dihydroxy-beta-phenylethoxy-O-[beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->3)]-[beta-D-xylopyfanosyl-(1-->6)]-4-O-caffeoyl-beta-D-glucopyranoside, respectively. The structures of all compounds were established by spectral evidence. Compounds 1-5 also demonstrated scavenging properties toward the 2,2-diphenyl-1-picrylhydrazyl radical in TLC autographic assays.