目的 研究内生真菌Fusarium-C39生物转化提高滇重楼药材皂苷类化学成分的含量，并增强重楼对癌细胞增殖的抑制作用，初步探讨主要甾体皂苷的生物转化机制。方法 将内生真菌Fusarium-C39分别与滇重楼药材固体发酵和与重楼总皂苷提取物液体发酵，比较发酵前后重楼总皂苷和重楼皂苷I、II、VII的含量变化及对肝癌HepG2细胞、肺癌A549细胞和结肠癌HT-29细胞增殖抑制作用的差异；采用UPLC/Q-TOF-MS技术研究发酵前后重楼皂苷类化学成分的变化，并结合甾体皂苷生物合成途径推测内生真菌Fusarium-C39生物转化提高重楼皂苷含量的机制。结果 与滇重楼药材相比较，发酵物中的重楼总皂苷、重楼皂苷I、II和VII的含量显著提高，对3种癌细胞增殖的抑制作用显著增强；人参皂苷Th、pseudoproto-Pb和parisyunnanoside B为Fusarium-C39菌株生物转化提高重楼皂苷I、II和VII含量的主要前体物质，它们在Fusarium-C39菌株的作用下发生了C₂₆糖基水解和环化反应，分别生成了重楼皂苷I、II和VII。结论 内生真菌Fusarium-C39可生物转化提高重楼皂苷含量，并增强重楼的抗肿瘤作用，转化机制可能与Fusarium-C39真菌促使重楼皂苷前体物质发生糖基水解和环化反应相关。

Objective To study the fermenting effect of endophytic fungus Fusarium-C39 with Dian chong lou (Paridis Rhizoma) on enhancing the saponins content and antitumour activity, and preliminarily investigate the biotransformation mechanism of main steroid saponins. Methods The endophytic fungus Fusarium-C39 was fermented with Paridis Rhizoma and total saponins extract, respectively. The contents of total saponins and polyphyllin I, II and VII from Paridis Rhizoma and its fermentation, and the inhibitory effects on the proliferation of HepG2, A549 and HT-29 of them were compared. UPLC/Q-TOF-MS was used to study the changes of saponins before and after fermentation, and the mechanism of biotransformation was deduced by referring with the biosynthesis pathway of steroidal saponins.Results Compared with Paridis Rhizoma, the contents of total saponins, polyphyllin I, II and VII in the fermentation were significantly increased, and the inhibitory effect on the proliferation of tumour cells was significantly enhanced. Th, pseudoproto-Pb and parisyunnanoside B were determined as main precursor substances. They were biotransformed into polyphyllin I, IIand VII by the deglycosylation of C₂₆ and cyclization under the catalysis of Fusarium-C39. Conclusion Endophytic fungus Fusarium-C39 could increase the saponins content and enhance the anti-tumor effect of Paridis Rhizoma by fermentation. The transformation mechanism was probably related to the deglycosylation and cyclization of the precursor substances catalyzed by Fusarium-C39.

R286.2

国家自然科学基金面上项目(81872967)