目的尋找選擇性水解甾體皂苷C-3位糖鏈末端糖基的微生物,同時制備甾體皂苷的去糖基衍生物.方法利用新月彎孢霉(3.438 1)培養(yǎng),對C-3位有雙糖基結(jié)構(gòu)的甾體皂苷類化合物重樓皂苷Ⅴ(化合物Ⅰ)、重樓皂苷Ⅵ(化合物Ⅱ)進行生物轉(zhuǎn)化;用反相C18開放柱進行轉(zhuǎn)化產(chǎn)物的分離純化,波譜方法鑒定其結(jié)構(gòu).結(jié)果新月彎孢霉(3.4381)均能將化合物Ⅰ和化合物ⅡC-3位糖鏈末端的鼠李糖水解,轉(zhuǎn)化為單糖基皂苷,轉(zhuǎn)化產(chǎn)物分別鑒定為薯蕷皂苷元-3-O-β-D-吡喃葡萄糖苷,即延齡草苷(trillin,化合物Ⅲ)和偏諾皂苷元-3-O-β-D-吡喃葡萄糖苷(化合物Ⅳ).結(jié)論首次發(fā)現(xiàn)新月彎孢霉(3.438 1)對重樓皂苷Ⅴ和重樓皂苷ⅥC-3位糖鏈的末端鼠李糖具有較強的水解能力.

Objective To find the microorganisms which hydrolyze sugar residues of steroidal saponins at C-3 position and to obtain their glucosyl-derivatives.Methods The enzymes secreted by fermentation ofCurvularia lunata(3.4381)in the culture medium were employed to transform polyphyllin V(compound I)and polyphyllin VI(compoundⅡ).The products were separated by means of chromato-graphy on C18 column and their structures were elucidated on the basis of spectral analyses.Results Compounds I andⅡcould be transformed by C.1unata(3.4381)and the main products were identified as diosgenin-3-0-β-D-glucopyranoside,named trillin (compound 11I)and pennogenin-3-O-8-D-91ucopyranoside(compound IV),respectively.Conclusion The terminal rhamnosyls of polyphy-llin V and polyphyllin VI at C-3 position could be hydrolyzed selectively byC.1unata(3.4381)for the first time.