Polyhydroxyoleanane-type triterpenoids from Combretum molle and their anti-inflammatory activity

The new triterpene saponin, β-d-glucopyranosyl 2α,3β,6β-trihydroxy-23-galloylolean-12-en-28-oate (1) together with the known combregenin (2), arjungenin (3), arjunglucoside I (4), and combreglucoside (5) were isolated from the stem bark of Combretum molle. Their structures were identified by interpretation of their spectral data, mainly ESIMS, 1D NMR (1H, 13C NMR, DEPT) and 2D NMR (COSY, HSQC and HMBC), and by comparison with the literature. Compounds 1-3 exhibited more significant anti-inflammatory activity against carrageenan-induced paw edema in rat compared to compounds 4 and 5.