Triterpenoid saponins from the roots of Clematis chinensis Osbeck.

J Asian Nat Prod Res. 2009; 11(5): 389-96Liu LF, Ma XL, Wang YX, Li FW, Li YM, Wan ZQ, Tang QLA new triterpenoid saponin named clematichinenoside AR(2), along with the six known compounds, was isolated and characterized from Clematis chinensis Osbeck (Ranunculaceae), a commonly used traditional Chinese medicine with anti-inflammatory and anti-rheumatoid activities. The structure of the new saponin was elucidated as 3-O-beta-[(O-alpha-L-rhamnopyranosyl-(1 --> 6)-O-beta-D-glucopyranosyl-(1 --> 4)-O-beta-D-glucopyranosyl-(1 --> 4)-O-beta-D-ribopyranosyl-(1 --> 3)-O-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl)oxy]olean-12-en-21alpha-hydroxy-28-oic acid-O-alpha-L-rhamnopyranosyl-(1 --> 4)-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (1) by spectral analysis and chemical methods. The effects of two major saponins (clematichinenosides AR and AR(2)) on the secretion of TNF-alpha in murine peritoneal macrophages induced by lipopolysaccharides were further investigated. The result indicated that a majority of triterpenoid saponins of this herb may be useful in the exploration of lead compounds for the treatment of some autoimmune diseases.