Abstract

Microbial transformation is an important tool to perform selective conversion of compounds to derivatives which are difficult to produce synthetically. In order to obtain icariside II and icaritin, the active components in Herba Epimedii in vivo, biotransformation studies using microbes as biocatalysts were carried out. Icariside II (2) and icaritin (3) were produced through biotransformation of icariin (1) using the fungi Hormoconis resinae and Mortierella ramanniana var. angulispora in 98% and 92% yields, respectively. In the subsequent transformation studies, 2 was deglycosylated to form 3 by Gliocladium deliquescens, whereas 3 was further converted to a novel compound icaritin-3-O-β-d-glucopyranoside (4) and previously known icaritin-3,7-O-β-d-diglucopyranoside (5) by Mucor hiemalis. Biological evaluation of these compounds using MTT assay exhibited potent cytotoxic activities against human cancer cell lines A549, A375P, and MCF-7, with icariin being the most active, indicating that glycosylation plays a role in the cytotoxic activity.

摘要

微生物转化是将化合物选择性转化为难以合成生产的衍生物的重要工具。为了在体内获得淫羊藿中的活性成分淫羊藿苷II和淫羊藿苷，进行了以微生物为生物催化剂的生物转化研究。淫羊藿苷 II ( 2 ) 和淫羊藿苷 ( 3 ) 是通过使用真菌Hormoconis resinae和Mortierella ramanniana var.对淫羊藿苷 ( 1 ) 进行生物转化而生产的。angulispora的产量分别为 98% 和 92%。在随后的转化研究中，2被去糖基化形成3Gliocladium deliquescens，而3进一步转化为新的化合物icaritin -3- O -β- d-吡喃葡萄糖苷 ( 4 ) 和之前已知的毛霉icaritin-3,7- O -β- d - diglucopyranoside ( 5 ) 。使用 MTT 测定法对这些化合物的生物学评估显示出对人类癌细胞系 A549、A375P 和 MCF-7 的有效细胞毒活性，其中淫羊藿苷是最活跃的，表明糖基化在细胞毒活性中起作用。