Chemical constituents from leaves and trunk bark ofRinorea oblongifolia(Violaceae)

Two new coruleoellagic acid derivatives, 3,4 ',5,5 ',-tetramethylcoruleoellagic acid(1); 3 ',4,4 ',5,5 '-pentamethylcoruleoellagic acid(2)and a new friedelane-type triterpene derivative rinol(5), were isolated from leaves and trunk bark ofRinorea oblongifolia(Violaceae) along with seven known compounds including 3,3 ',4,4 ',5 '-pentamethylcoruleoellagic acid(3), hexamethylcoruleoellagic acid(4),28-hydroxyfriedelin(6),friedelin(7),friedelan-3-ol(8),scopoletin(9)and beta-sitosterol-3-O-beta-D-glucopyranoside(10).Their structures were elucidated by means of spectroscopic methods including IR, 1D and 2D NMR in conjunction with mass spectrometry. Crude extracts of leaves and trunk bark as well as compounds1-4were evaluated for their antibacterial activities against 7 pathogenic bacterial strains (Streptococcus pneumoniaeATCC49619,Staphylococcus aureusATCC 43300,Klepsiella pneumoniaeATCC 700603,Haemophilus influenzaATCC 49247,Escherichia coliATCC 25922,Pseudomonas aeruginosaHM601,Staphylococcus aureusBAA 977). Compound(3)displayed noteworthy activity againstHaemophilus influenzawith MIC value of 9.38 mu g/mL.