[关键词]
[摘要]
目的 研究两面针Zanthoxylum nitidum根提取物中具有抗菌活性的化学成分。方法 以药理活性测试为导向,综合利用硅胶柱、氧化铝柱、制备TLC和制备HPLC等色谱技术分离两面针提取物活性成分,采用NMR和MS谱学数据及其理化性质鉴定化合物结构。结果 从两面针根提取物中分离得到11个化合物,分别鉴定为茵芋碱(1)、氧化白屈菜红碱(2)、8-甲氧基二氢白屈菜红碱(3)、β-谷甾醇(4)、L-芝麻脂素(5)、8-甲氧基-9-羟基白屈菜红碱(6)、4-羟基-N-甲基脯氨酸(7)、鹅掌楸碱(8)、勒樘碱(9)、两面针碱(10)、苯甲酸异丁酯(11)。抗菌测试表明化合物1、3、6、8和10均能显著抑制金黄色葡萄球菌,其中化合物8抑菌效果最强,MIC为31.3 μg/mL,较优于对照药磺胺甲 唑;进一步测试表明化合物8能显著抑制临床分离的对6大类抗生素均耐药的耐甲氧西林金黄色葡萄球菌(MRSA),MIC为93.8 μg/mL。结论 基于活性导向法从两面针根提取物中分离鉴定出能显著抑制金黄色葡萄球菌生物碱活性成分,化合物7、9和11为首次从该植物分离获得,首次发现化合物8对临床多药耐药性MRSA具有较强杀菌活性,为开发新型超级细菌抗菌素提供参考。
[Key word]
[Abstract]
Objective To isolate and identify the antibacterial constituents from the roots of Zanthoxylum nitidum. Methods Bioassay-guided fractionation led to the isolation of compounds from the roots of Z. nitidum by using various chromatographic techniques such as silica gel, alumina, preparative TLC, and HPLC, and their chemical structures were then elucidated on the basis of spectroscopic data, including NMR, MS analysis, and their physicochemical properties. Results Eleven compounds were isolated from the bioactive extracts in the roots of Z. nitidum and then were identified as skimmianine (1), oxychelerythrine (2), 8-methoxy- dihydrochelerythrine (3), β-sitosterol (4), L-sesamin (5), 8-methoxy-9-demethoxyldihydrochelerythrine (6), 4-hydroxy-N- methylproline (7), liriodenine (8), avicine (9), nitidine (10), and isobutyl benzoate (11), respectively. Compounds 1, 3, 6, 8, and 10 showed the potential inhibition on Staphylococcus aureus. Compound 8 showed the most potential inhibitory activity with MIC value of 31.3 μg/mL; Further studies demonstrated that compound 8 inhibited the clinical multidrug-resistant methicillin-resistant Staphylococcus aureus (MRSA) activity with MIC value of 93.8 μg/mL, significantly. Conclusion A series of bioactive alkaloids with the anti-staphylococcal activities were identified from the roots of Z. nitidum. Compounds 7, 9, and 11 are obtained from this plant for the first time, and the potential anti-staphylococcal activity of compound 8 against MRSA has been demonstrated, which has provided the chemical template as a new anti-bacterial agent against clinical multidrug-resistant MRSA infection.
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[基金项目]
广东省教育部产学研结合项目(2009B090300202);广东省“211工程”三期重点学科建设项目“南药的现代研究与综合开发利用”(粤发改社[2009]319号)