Abstract: A new triterpenoid saponin was isolated from Lonicera fulvotomentosa. The structure of the new tri-terpenoid saponin, named Fulvotomentoside B, was elucidated as 3-O-β-D-xylopyranosyl(1→3)-α-L-rhamnopyranosyl(1→2)-α-L-arabinopyranosyl hederagenin-28-O-β-D-xylopyranosyl(1→6)-β-D-glucopyranosyl ester on the basis of spectroscopic analysis as well as chemical methods. In addition, the structure of Fulvotomentoside A, the previously reported major saponin, was revised, and it should be 3-O-β-D-xylopyranosyl(1→3)-α-L-rhamnopyranosyl(1→2)-α-L-arabinopyranosyl hederagenin-28-O-β-D-glucopyranosy(1→6)-β-D-glucopyranosyl ester(Decaisoside E) on the basis of careful analyses of new spectroscopical data.

Key words: Lonicera fulvotomentosa, Triterpenoid saponin, Fulvotomentoside B