杨梅素糖苷衍生物的合成及其抗菌活性研究

摘要：目的 设计合成杨梅素类糖苷衍生物，并进行抗菌活性研究。方法 以天然产物杨梅苷为起始原料，经过保护基策略、糖苷化反应、酯化反应制备得到一系列新型半乳糖苷衍生物，对杨梅素类衍生物进行了抑菌活性研究。结果 以杨梅苷为原料，设计合成了14个杨梅素类衍生物，其中包含有8个未见文献报道的新型糖苷化合物，其结构经核磁、ESI-MS进行了确证。体外抗菌活性结果显示，8个杨梅素衍生物具有较杨梅素和杨梅苷更强的抗菌活性，其中，化合物9a-1~9a-4对金黄色葡萄球菌和表皮葡萄球菌的抗菌活性MIC值为1~8 μg/mL。结论 本研究首次以杨梅苷作为原料，设计了新的合成路线，并对合成中的关键反应条件进行了优化，构建了一条高效快捷的杨梅素衍生物的制备方法。化合物的初步活性结果显示，黄酮醇3位羟基半乳糖修饰可以显著提高杨梅素的抗菌活性，为杨梅素的进一步抗菌化合物的寻找提供了新的线索。

Synthesis and antibacterial activity evaluation of myricetin diacylglycoside derivatives

Abstract Objective Design, synthesis, and antibacterial activity evaluation of myricetin glycoside derivatives. Methods Using natural product myricetin as a starting material, a series of novel galactoside derivatives were prepared through a new protocol containing protecting group strategies, glycosylation reactions, and esterification reactions. The antibacterial activity of myricetin derivatives was evaluated. Results Based on the core scaffold of myricetin, 14 myricetin derivatives were designed and synthesized, including 8 glycoside analogues which were first reported. The desired compounds were characterized by 1H NMR, 13C NMR, and ESI-MS. The results of in vitro antibacterial activity showed that 8 myricetin derivatives had stronger antibacterial activity than myricetin. Conclusion In this study, a new synthetic route was first designed using myricetin as a starting material, and thecorresponding reaction conditions were individually optimized, and an efficient synthetic protocol for myricetin glycoside derivatives was reported. In addition, the preliminary activity results of those compounds showed that the modification of flavonol 3-hydroxygalactose could significantly increase the antibacterial activity of myricetin, which provided new clues for the further