Chemical constituents and antibacterial activities of the stems of Homalium Stenophyllum Merr. et Chun

AIM To study chemical constituents and antibacterial activities of the stems of Homalium stenophyllum Merr. et Chun. METHODS The isolation and purification of stems extract were performed on silica,C18reversed-phase silica,Sephadex LH-20 gel column and recrystallization,the chemical structures of isolated compounds were elucidated by ESI-MS,1H-NMR and13C-NMR. Then the antibacterial activities of them were tested by serial dilution with 96-well microtiter plates. RESULTS Three triterpenoids( 1-3) and eight phenolic acids( 4-11) were isolated from this plant and identified as 3α-O-trans-coumaroylbetulinicacid( 1),pyracrenic acid( 2),betulinic acid( 3),O-anisic acid( 4),vanillin( 5),3,5-dimethoxy-4-hydroxybenzaldehyde( 6),salicyl alcohol( 7),4-ethoxy-3-hydroxymethylphenol( 8),trans-pcoumaraldehyde( 9),coniferaldehyde( 10) and benzoic acid( 11). CONCLUSION All compounds are isolated from the stems of H. stenophyllum for the first time. Among them,Compound 8 shows a broad antibacterial activity. Compounds 1-3,8,9 and 11 exhibit strong antibacterial activities against E. coli with the MIC values of 1. 25 μg / m L. Compounds 6 and 8 have also significant antibacterial activities against B. subtilis with the MIC values of 1. 25 μg / m L.