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 screening of extracts of these strains showed the peak position of the strain M-20(retention time,5.314 min) was very 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 camptothecin yielded M+H+ at m/z 349.2,demonstrating the isolate M-20 produced camptothecin with a yield of 233.3 μg/L.The strain M-20 was identified as Xylaria sp.according to its sequence assays and morphological characteristics as well.