一株喜树内生真菌的分离及其产喜树碱的初步分析

Isolation of an Endophytic Fungus from Camptotheca acuminata and Its Preliminary Analysis of Camptothecin Production

从秦巴山区喜树中分离到42株内生真菌,其发酵产物经HPLC检测发现,菌株M-20氯仿-甲醇提取物的出峰时间为5.314 min,同喜树碱标准品的出峰时间(5.453 mim)靠近。HPLC-MS分析显示,菌株M-20产生一个M+H+核质比为349.4的离子峰,喜树碱标准品的M+H+核质比为349.2。上述结果表明,菌株M-20代谢产喜树碱,含量为233.3μg/L。结合形态特征和ITS序列分析,将菌株M-20初步鉴定为炭角菌属(Xylaria)真菌。

In the survey of the endophytic fungi associated with Camptotheca acuminata grown at the Qinba Mountainous regions, we obtained 42 fungal isolates. HPLC sition of the strain M-20 （retention time, 5. 314 min） was screening of extracts of these strains showed the peak povery close to that of the authentic camptothecin （5. 453 mim）. HPLC-MS analysis indicated the fungal camptothecin produced a fragment peak M ＋ H ＋ at m/z 349.4, and the reference camptotheein yielded M ＋ H ＋ at m/z 349.2, demonstrating the isolate M-20 produced eamptothecin with a yield of 233.3 μg/L. The strain M-20 was identified as Xylaria sp. according to its sequence assays and mor-phological characteristics as well.