Abstract: Microbial transformation of Gynostemma pentaphyllum from Fujian by two fungi of Aspergillus niger and A. nidulans was studied. After gypenosides being fermented in liquid for 2 d using the foregoing fungi at 37 ℃, HPLC analysis of the transformed products of gypenoside via microorganism indicated that the composition of the fermentation broth changed obviously. To compare the activity of transformed substrate and products of gypenosides, the anticancer activity was evaluated by MTT assay. The results showed that the transformed products of gypenoside via microorganism exhibited the obvious cytotoxic activity on human hepatoma cells SMCC7721 and Bel7402, but the transformed substrate of gypenosides was inactive. Products transformed by A. nidulans and A. niger had inhibitory effect on the growth of SMCC7721 cells for 72 h with the 50% inhibitory concentration (IC₅₀) of 92.00 and 40.60 mg·mL^-1 respectively, with 49.06 and 125.38 mg·mL^-1 on the growth of Bel7402 cells. The results indicated that microbial transformation of the gypenosides from G. pentaphyllum via two fungi had produced the anticancer activity constitutes. The research provided new research ideas for the later works of bioscreening and separation of active ingredients from G. pentaphyllum.

Key words: Fujian Gynostemma pentaphyllum, gypenoside, microbial transformation, anticancer activity

摘要： 研究黑曲霉和构巢曲霉两种真菌对福建绞股蓝皂苷的微生物转化。在37 ℃条件下液体发酵2 d后，HPLC分析表明，微生物转化后成分发生明显变化；利用MTT法测定抗癌活性，比较绞股蓝皂苷微生物转化前后活性变化，结果表明，转化前绞股蓝皂苷转化底物无抗癌活性，两种真菌转化产物有显著的抗癌活性。构巢曲霉和黑曲霉的转化产物对肝癌细胞SMCC7721增殖的72 h半抑制率IC₅₀值分别为92.00、40.60 mg·mL^-1；对肝癌细胞Bel7402增殖的72 h半抑制率IC50值分别为49.06、125.38 mg·mL^-1。说明两种真菌对绞股蓝皂苷微生物转化产生具有抗癌活性的成分，为从绞股蓝中筛选和分离活性成分提供新的研究思路。

关键词: 福建绞股蓝, 绞股蓝皂苷, 微生物转化, 抗癌活性