ABSTRACT
Objective: To investigate the sesquiterpenoid constituents from Aquilaria sinensis. Methods: The chemical constituents were isolated and purified by various separation techniques such as silica gel, ODS, Sephadex LH-20, and preparative high- performance liquid chromatography, and their structures were determined according to their physicochemical properties, MS, 1D, and 2D NMR. The antibacterial activity of the obtained compounds against methicillin-resistant Staphylococcus aureus was tested by 96-well plate microdilution method. Results: Seven sesquiterpenoids were obtained from 95% ethanol aqueous extract of Aquilaria sinensis and their structures were identified as (+)-4a,5-dimethyl-3-(prop-1-en-2yl)-octahydronaphthalene-2β,8a-diol (1), baimuxinic acid (2), baimuxinol (3), vetaspira-2(11),6-dien-14-al (4), baimuxinal (5), (-)-10-epi-γ-eudesmol (6), and 9β-hydroxyl-α-agarofuran (7). The minimum inhibitory concentration (MIC) of compound 1 against methicillin-resistant Staphylococcus aureus was 210 μmol/L. Conclusion: Compound 1 is a new compound named as 2β,8aα-dihydroxy-11-en-eremophilane, which has a good inhibitory effect against methicillin-resistant Staphylococcus aureus.