Taraxasterane-type triterpene and neolignans from Geum japonicum Thunb. var. chinense F. Bolle.

The phytochemical investigation of the ethanolic extract of the whole plants of Geum japonicum Thunb. var. chinense F. Bolle yielded four new compounds: 20 β,28-epoxy-28-hydroxytaraxasteran-3 β-ol (1), (7R,8R)-4-hydroxy-9'-O-(α-L-rhamnopyranosyl)-3,3',5'-trimethoxy-8-O-4'-neolignan (2), (7R,8S)-4-hydroxy-9'-O-(α-L-rhamnopyranosyl)-3,3',5'-trimethoxy-8-O-4'-neolignan (3), and (7S,8S)-5-methoxycupressoside A (4), as well as 40 other known compounds. Structures were elucidated by physical, chemical, and spectroscopic methods, including 1D and 2D NMR, HRESIMS, and CD experiments. The taraxasterane-type triterpene (1) and lignans (2- 6) are reported for the first time from the GEUM genus. Moreover, all compounds were evaluated for anti-inflammatory activities against NO production in RAW264.7 macrophages, and only moderate activities were detected.