摘要 : Two new anthraquinones, 2,6-dimethyl-3-hydroxy-5-methoxyanthraquinone (1) and 2,5-dimethyl-6-hydroxy-3-methoxyanthraquinone (2), were isolated from the twigs of Cassia alata. Their structures were determined by means of HR-ESI-MS ... 展开 Two new anthraquinones, 2,6-dimethyl-3-hydroxy-5-methoxyanthraquinone (1) and 2,5-dimethyl-6-hydroxy-3-methoxyanthraquinone (2), were isolated from the twigs of Cassia alata. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1 and 2 were tested for their antibacterial activity. The results showed that both compounds exhibited high antibacterial activity against 11 microbial strains isolated from the saliva of smokers. 收起