Two New Triterpene Saponins from the Anti‐Inflammatory Saponin Fraction of Ilex pubescens Root

The saponin fraction from the ethanolic extracts of the root of Ilex pubescens Hook . et Arn . (Ilexaceae) was found to exhibit potent anti‐inflammatory effects on carrageenan‐induced paw edema in rats. Two novel triterpene saponins, pubescenosides C and D ( 1 and 2 , resp.), together with five known saponins were isolated from this saponin fraction. The structures of 1 and 2 were elucidated as (20 β )‐3‐ O ‐[ β ‐ D ‐glucopyranosyl‐(1→2)‐ β ‐ D ‐xylopyranosyl]ursa‐12,18‐dien‐28‐oic acid 28‐ O ‐ β ‐ D ‐glucopyranosyl ester, and (20 β )‐3‐ O ‐[ α ‐ L ‐rhamnopyranosyl‐(1→2)‐ β ‐ D ‐glucopyranosyl‐(1→2)‐ β ‐ D ‐xylopyranosyl]ursa‐ 12,18‐dien‐28‐oic acid 28‐ O ‐ β ‐ D ‐glucopyranosyl ester, respectively, on the basis of chemical and spectroscopic data. Five known saponins isolated from the saponin fraction were identified as ilexsaponin B 1 , B 2 , B 3 , A 1 , and chikusetsusaponin IV a ( 3 – 7 , resp.).