Jiale Wang

A new ganoderic acid from Ganoderma lucidum mycelia

A new ganoderic acid (GA), 7-O-ethyl ganoderic acid O (GA-O) (1), together with two known compounds, GA-T (2) and GA-Me (3), was isolated and purified from fermented mycelia of Ganoderma lucidum. The structure of the new triterpenoid was elucidated on the basis of the interpretation of extensive spectroscopic data (HR-MS, IR, UV, 1D and 2D NMR) as 3α,15α,22-triacetoxy-7α-ethoxy-5α-lanost-8,24E-dien-26-oic acid. The new compound was found to contain a rare ethoxyl group at C-7. In addition, its cytotoxicity against 95D and HeLa human cancer cell lines was also evaluated.

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. Biotechnol. Bioeng. 2012; 109:754–762.

Recovery of ganoderic acids from Ganoderma lucidum mycelia by macroporous adsorption resins

In this work, the performance and adsorption characteristics of macroporous resins for the recovery and enrichment of ganoderic acid (GA)-Mk and GA-T from Ganoderma lucidum mycelia were systematically evaluated. ADS-8 resin displayed the best adsorption and desorption capacities among the tested resins based on batch experiments. The interaction between solute and ADS-8 resin at different temperatures was described in terms of Langmuir and Freundlich isotherms, and the equilibrium experimental data were well fitted to the two isotherms. Thermodynamic analysis indicated the exothermic and spontaneous nature of the adsorption process. The adsorption capacity of ADS-8 resin was found to depend strongly on the pH value of the initial solution. Dynamic adsorption and desorption tests were performed on an ADS-8 resin-packed column to obtain optimal parameters for recovering GA-Mk and GAT from G. lucidum extract. Under optimized conditions, a laboratory scale-up preparation of GA-Mk and GA-T was carried out. The contents of GA-Mk and GA-T were increased from 45 to 22 mg/g in the crude extract to 352 and 141 mg/g in the final product with recovery yields of 90.1 and 72.2%, respectively. These results demonstrated that ADS-8 resin chromatography could act as a useful approach for obtaining ganoderic acids from G. lucidum mycelia.