Chemical constituents from the leaves and liana of Salacia nitida (Benth.) N.E.Br. (Celastraceae) and their antimicrobial activities

One benzophenone, 4′-hydroxy-2,4,6-trimethoxybenzophenone (1) was isolated from the liana and leaves of Salacia nitida (Benth.) N.E.Br., together with n-hexacosane (2), 29-hydroxyfriedelane (3), 3β-friedelinol (4), n-hexacosan-1-ol (5), n-octacosan-1-ol (6), mangiferin (7), β-sitosterol-3-O-β-D-glucopyranoside (8), friedelin (9), 30-hydroxyfriedelin (10), salaspermic acid (11), 22β-epi-maytenfolic acid (12), orthosphenic acid (13), maltose (14), D-mannitol (15), cangoronine (16), 7-hydroxyfriedelane-1,3-dione (17), tingenone (18), pristimerin (19), α-amyrin acetate (20), β-sitosterol (21) and stigmasterol (22), 21-hydroxyfriedelan-3-one (23), abruslactone A (24), and 2α-hydroxypopulnonic acid (25). The structures of the isolated compounds were established by means of spectroscopic analysis. In addition, the structure of (1) was confirmed by its X-ray diffraction. Compounds (1), (7), (10)-(11), (13), (16)-(19) and (25) were evaluated for their antimicrobial activities. Compound (18) showed a significant activity against Staphylococcus aureus (MIC = 23.8 µM) while compounds (11) and (19) exhibited moderate inhibiting effect against Staphylococcus aureus (MIC = 53.8 µM) and Candida glabrata (MIC = 105.9 µM), respectively.