The chemical constituents of triterpenoids and steroids and their antibacterial activity of Syzygium samarangense

Various separation techniques including normal and adverse silica gel and Sephadex LH-20 gel column chramatography were used to investigate the chemical constituents from the leaves of Syzygium samarangense. In result, twenty compounds, 11-oxo-α-amyrin (1), ursolic acid (2), 2α-hydroxy ursolic acid (3), asiatic acid (4), 23-hydroxy ursolic acid (5), 2α,3β-dihydroxy-taraxer-20-en-28-oic acid (6), ulmoidol (7), maslinic acid (8), 2α,3β-23-trihydroxyolean-12-en-28-oic acid (9), friedelin (10), 24-methylene cycoartanol (11), cycloartenol (12), (24R)-cycloartane-3β,24,25-triol (13), euphol (14), euphorbol (15), schleicheol 1(16), schleicheol 2 (17), 7-oxo-β-sitosterol (18), 6-hydroxy-stigmast-4-en-3-one (19) and 3β-hydroxy-stigmast-7-en-6-one (20) were isolated and determined and their structures were identified by NMR spectroscopic data and comparison with values reported. Except for compounds 2 and 10, all other ones were isolated from S. samarangense for the first time. The NMR data of compounds 1 and 20 were firstly reported. Compounds 1, 3−10 were screened for antibacterial activity and all of them did not show obvious activity（MIC > 100 μg/mL）.