Enhanced recovery of four antitumor ganoderic acids from Ganoderma lucidum mycelia by a novel process of simultaneous extraction and hydrolysis

Ganoderic acids (GAs) Mk, T, S and R exhibit promising anti-tumor effect, but they are difficult to purify from Ganoderma lucidum mycelia due to the presence of numerous analogs. In this work, a novel and efficient extraction/hydrolysis method was developed for the recovery of these four GAs from the mycelia of G. lucidum. By using a 50% aqueous ethanol solution containing 50 mmol/l HCl as extractant, extraction of GAs from mycelia and conversion of analogs impurities into the products of interest could be achieved in one step. This one-pot extraction/hydrolysis process increased the yield of GA-Mk, -T, -S and -R to 242%, 389%, 189% and 420%, respectively, compared to a raw sample without hydrolysis. Simultaneous purification of these four GAs was readily achieved in a single RP-HPLC run due to the conversion of analog impurities into corresponding desired GAs, and the purity and recovery of these four GAs were over 97% and 90%, respectively. The results demonstrated that the simultaneous extraction and hydrolysis process is simple and efficient and thus can act as a useful approach for enhanced recovery of those four GAs from G. lucidum mycelia.