目的 研究桃金娘Rhodomyrtus tomentosa叶的化学成分及其抗菌活性。方法 应用各种色谱技术对桃金娘叶的粗提物进行分离纯化，并利用质谱及核磁等波谱技术鉴定化合物结构；采用微量稀释法对所得化合物进行抗菌活性测试。结果 从桃金娘叶95%乙醇提取物中分离得到21个化合物，分别鉴定为生育酚（1）、新生育酚（2）、生育酚-对苯醌（3）、生育酚A（4）、（-）-α-tocospirone（5）、rhodomyrtosone F（6）、rhodomyrtosone C（7）、watsonianone A（8）、rhodomyrtone（9）、2,6-二羟基-苯甲酸苯甲酯（10）、肉桂酸甲酯（11）、柚皮素（12）、槲皮素（13）、杨梅素（14）、3,7,3'-三甲氧基-5,4',5'-三羟基黄酮（15）、5,7,3',5'-四羟基黄酮（16）、艾纳香素（17）、7,4'-二甲氧基二氢槲皮素（18）、4'-二甲氧基二氢槲皮素（19）、2,4,7,8,9,10-六羟基-3-甲氧基蒽-6-O-β-L-吡喃鼠李糖苷（20）、4,8,9,10-四羟基-2,3,7-三甲氧基蒽-6-O-β-D-吡喃葡萄糖苷（21）。结论 化合物6为新天然产物，化合物2～5，10～13及15～19为首次从该属植物中分离得到，抗菌实验结果显示化合物3及6～9具有一定的抗菌活性。

Objective To study the chemical constituents from the leaves of Rhodomyrtus tomentosa and its antibacterial activities. Methods The compounds were isolated and purified by various column chromatographies. Their structures were elucidated by means of spectral analyses (MS and NMR). The antibacterial activity of the compounds was tested by micro dilution method Results A total of 21 compounds were isolated from the 95% ethanol extract in the leaves of R. tomentosa and identified as (2R, 4'R, 8'R)-α-tocopherol (1), (2R, 4'R, 8'R)-β-tocopherol (2), α-tocopherol-quinone (3), α-tocopherol A (4), (-)-a-tocospirone (5), rhodomyrtosone F (6), rhodomyrtosone C (7), watsonianone A (8), rhodomyrtone (9), verimol K (10), methyl cinnamate (11), naringenin (12), quercetin (13), myricetin (14), 3, 7, 3'-trimethoxy-5, 4', 5'-trihydroxy flavone (15), 5, 7, 3', 5'- tetrahydroxyflavanone (16), blumeatin (17), dihydroquercetin-7, 4'-dimethylether (18), dihydroquercetin-4'-dimethoxy (19), 2, 4, 7, 8, 9, 10-hexahydroxy-3-methoxyanthracene-6-O-β-L-rhamnopyranoside (20), and 4, 8, 9, 10-tetrahydroxy-2, 3, 7-trimethoxyanthracene-6-O-β-D-glucopyranoside (21). Conclusion Compound 6 is a new natural product and compounds 2-5, 10-13, and 15-19 are isolated from the plants of Rhodomyrtus (DC.) Reich for the first time. Compounds 3 and 6-9 exhibit the antibacterial activities.

海南省自然科学基金资助项目（20152038）；海南省高等学校科学研究项目（Hnky2015-21）