Enhanced recovery of antitumor ganoderic acid T from Ganoderma lucidum mycelia by novel chemical conversion strategy.
The removal of analog impurities with a very small sample size presents a major challenge in the purification of high-valued biochemicals such as those derived from fermentation or herbs. Ganoderic acid T (GA-T), an antitumor drug candidate, is very difficult to purify from the mycelia of medicinal mushroom Ganoderma lucidum due to co-purifying analog impurities. A novel pretreatment process with three consecutive chemical conversion steps, namely hydrolysis-acetylation-hydrolysis, was developed to convert two key analog impurities (7-O-ethyl GA-O and GA-Mk) to GA-T. It increased the GA-T amount in the 100 g dried mycelia from the initial 0.444 g to 1.621 g after the pretreatment, representing an apparent yield of 365% for the pretreatment. If the yield basis were the initial GA-T amount plus the GA-T amount from 100% conversion of 7-O-ethyl GA-O and GA-Mk in the crude extract, the yield, termed adjusted yield for the pretreatment in this work, would still reach 90.8%. Furthermore, the subsequent RP-HPLC purification was considerably enhanced due to the conversion of the analog impurities. This game-changer strategy achieved a daily GA-T throughput of 2.9 g with 95% purity (mass based). Even at the laboratory scale, it is now possible to produce a sufficient amount of GA-T for small-scale pharmacological and clinical evaluations. The approach of converting analog impurities that are otherwise difficult to remove to the product in a bioseparation process may be useful to achieve enhanced recovery of other medicinally useful natural products.
State Key Laboratory of Microbial Metabolism and Laboratory of Molecular Biochemical Engineering, Department of Bioengineering, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China.
Jia-Le
JL
Wang
Tingyue
T
Gu
Jian-Jiang
JJ
Zhong
D000107:Acetylation; D000970:Antineoplastic Agents / Q000302:isolation & purification* / Q000378:metabolism; D001709:Biotechnology / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D006868:Hydrolysis; D007810:Lanosterol / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000378:metabolism; D025282:Mycelium / Q000737:chemistry* / Q000378:metabolism; D020940:Reishi / Q000737:chemistry* / Q000378:metabolism
D000970:Antineoplastic Agents; C550530:ganoderic acid T; D007810:Lanosterol