一种真菌对人参皂苷Rg_3的转化

Fungal biotransformation of ginsenoside Rg_3

【目的】筛选长白山人参土壤中的活性微生物,转化人参总皂苷及单体人参皂苷产生稀有抗肿瘤成份。【方法】从长白山人参根际土壤中分离各类菌株,对人参总皂苷及单体人参皂苷进行微生物转化,并通过硅胶柱层析等方法对转化产物进行分离纯化,采用波谱解析及理化常数对其进行结构鉴定;结合菌落形态、产孢结构、孢子形态特征以及菌株ITS rDNA核酸序列分析,对活性菌株进行鉴定。【结果】从长白山人参根际土壤中分离各类真菌菌株68株,有12株菌株对人参总皂苷有转化活性,其中菌株SYP2353对二醇组人参皂苷Rg3具有较强的转化活性。【结论】阳性菌株SYP2353被鉴定为疣孢漆斑菌(Myrothecium verrucaria),能将人参皂苷Rg3转化为稀有人参皂苷Rh2及二醇组人参皂苷苷元PPD,为稀有人参皂苷Rh2的制备提供了新的方法。

[Objective] Ginsenosides are important bioactive compounds in Ginseng. Sugar chains of ginsenosides are closely related to the bioactivity. Rare ginsenosides can be achieved by modifying sugar chains through biotransformation Samples of Ginseng root soils, collected from Changbai Mountain, were used to screen active microorganism which can transform total ginsenosides and single ginsenoside, so as to obtain anti-tumor components. [Methods] The strains were isolated and screened on solid transfer medium and yield transfer process for active strains. Then the active strains were tested for their biotransformation properties by using different purified ginsenosides, including ginsenoside Rg3. The biotransformation products were separated and purified through column chromatography on silica gel （300mesh）, and identified by spectral analysis and physical constants. Simultaneously, the active strain was identified based on morphological characteristics of colonies, conidium and conidiophore, as well as ITS-5.8S rDNA sequences. [Results] Total 68 fungal strains were isolated and 12 active strains showed positive activity on total ginsenosides. One strain, SYP2353, was found to have the strong activity on Rg〉 [Conclusion] The active strain SYP2353 was identified as Myrothecium verrucaria, and the biotransformation products of Rg3 were identified to be rare ginsenoside Rh2 and aglycon PPD.