文献类型：期刊文献

英文题名：Investigation on the mechanisms for biotransformation of saponins to diosgenin

作者：Zhu, Yuling[1,2,3];Zhu, Hancan[4];Qiu, Muqing[1];Zhu, Tingting[5];Ni, Jinren[2,3]

机构：[1]Shaoxing Univ, Coll Life Sci, Shaoxing 312000, Peoples R China;[2]Minist Educ, Key Lab Water & Sediment Sci, Beijing 100087, Peoples R China;[3]Peking Univ, Dept Environm Engn, Beijing 100087, Peoples R China;[4]Shaoxing Univ, Math Informat Coll, Shaoxing 312000, Peoples R China;[5]Shenzhen Acad Environm Sci, State Environm Protect Key Lab Drinking Water Sou, Shenzhen 518001, Peoples R China

年份：2014

卷号：30

期号：1

起止页码：143

外文期刊名：WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY

收录：SCI-EXPANDED(收录号：WOS:000329248200015)、、EI(收录号：20140217188885)、Scopus(收录号：2-s2.0-84891661015)、WOS

基金：This work is financially supported by the National Natural Science Foundation of China (No. 21206093), the Zhejiang Provincial Natural Science Foundation of China (No. LQ12E08005 and No. LY12D01002), and Foundation of Shaoxing University (No. 20115002).

语种：英文

外文关键词：Saponin hydrolase; Saponins; Diosgenin; Model; Enzymatic hydrolysis

外文摘要：In order to improve the efficiency of biotransformation of saponins in Dioscorea zingiberensis to diosgenin, a new enzymatic model was developed to investigate the mechanism of the metabolic systems. Four main saponin hydrolases (E1, E2, E3 and E4) were purified from Trichoderma reesei. Using progracillin as substrate, the enzymatic hydrolysis experiments with E1, E2, E3 and E4 were carried out respectively. Saponin concentrations during each biotransformation reaction were constructed with a kinetic model consisting of a few Michaelis-Menten equations. During biotransformation, C-26 glycoside and C-3 terminal glycoside were cleaved sequentially from saponins by E1, E2, E3 and E4. Then C-3 terminal rhamnoside and C-3 glycoside were released from the aglycone stepwisely by E2 and E3, to yield diosgenin. E2 and E3 were the key enzymes in the system, and cleavage of the C-3 glycoside from saponins was the rate-limiting step in the biotransformation process. The proposed enzymatic model might be used to analyze the mechanism for biotransformation of saponins to diosgenin.