Abstract
A high performance liquid chromatography-diode array detection-atmospheric pressure chemical ionization-ion trap mass spectrometry (HPLC-DAD-APCI-MS/MS) was applied to determine the contents of ergosterol and ergosterol peroxide (EPO) in seventeen fruiting bodies and five mycelia of medicinal fungi, which are used as important traditional or folk medicines for prevention and treatment of cancer. A comprehensive validation of the method, including sensitivity, linearity, reproducibility and recovery was conducted using the optimized chromatographic conditions; an HPLC-DAD method was used for determination of ergosterol and an HPLC-APCI-Ion Trap MS method was adopted for determination of EPO. The calibration lines of ergosterol and EPO were obtained with R2>0.999 (both standard compounds), and the limits of detection (S/N=3) were estimated to be 16.4 and 1.8 ng, respectively. The relative standard deviations of the respective methods were less than 4.81 and 6.30% (n=5) for intraday and interday assays, and the recoveries were 94.6-98.4% and 93.0-99.6% for ergosterol and EPO, respectively. Of the medicinal fungi examined, the content of ergosterol was found to be the highest in the fruiting body of Grifola frondosa (0.283%, w/w), while that of EPO was the highest in the fruiting body of Ganoderma colossum (0.053%, w/w). The described analytical methods are rapid, accurate and applicable to the quantitative determination of ergosterol and EPO in other fungi and their commercial products.
