蝉虫草（蝉花）来源的化合物鉴定与抗菌活性检测

蝉虫草（蝉花）是我国重要的传统中药材之一,用于治疗慢性肾炎等,但对其活性成分的研究仍不充分。本文采用硅胶柱、凝胶柱、ODS柱分离,以及HPLC等色谱技术,对蝉虫草子实体样品的乙酸乙酯提取物进行分离纯化,得到3个化合物。根据波谱学数据,化合物1-3分别鉴定为(E,E)-9-酮-10,12-十八碳二烯酸(E,E)-9-oxooctadeca-10,12-dienoic acid（1）、麦角甾醇ergosterol（2）和白僵菌酮bassiatin（3）,其中化合物1为首次从蝉虫草中分离获得。抑菌实验表明,3个化合物均对革兰氏阴性大肠杆菌Escherichia coli和革兰氏阳性枯草芽孢杆菌Bacillus subtilis有显著的抑菌活性,化合物1和3还对条件致病真菌白色念珠菌Candida albicans有明显的抑菌活性。本文的研究结果丰富了蝉虫草的活性化合物组成。

Identification and antimicrobial assays of the bioactive components isolated from the medicinal fungus Cordyceps cicadae

The “cicada flower”, i.e., the dead cicada nymphs parasitized by Cordyceps cicadae, is one of the valued traditional Chinese medicines that has been using to treat chronic nephritis. However, its bioactive components are still poorly investigated. In this study, the ethyl acetate extracts of the fruiting bodies of C. cicadae harvested from an artificial medium were sequentially separated by using silica gel column, Sephadex LH-20 resin column, ostadecylsilane column and high performance liquid chromatography. Three compounds were purified and structurally determined as (E,E)-9-oxooctadeca-10,12-dienoic acid (1), ergosterol (2), and bassiatin (3) by spectroscopy analysis. Among them, compound 1 was isolated from C. cicadae for the first time. Antimicrobial assays indicated that the compounds 1 and 3 showed obviously antibacterial activities against Bacillus subtilis and Escherichia coli, and antifungal activity against Candida albicans. Compound 2 only demonstrated considerable antibacterial activities. The data of this study advanced the understanding of the bioactive constituents of C. cicadae.