Rapid differentiation of Ganoderma species by direct ionization mass spectrometry

In this study, direct ionization mass spectrometry (DI-MS) has been developed for rapid differentiation of Ganoderma (known as Lingzhi in Chinese), a very popular and valuable herbal medicine. Characteristic mass spectra can be generated by DI-MS directly from the raw herbal medicines with the application of a high voltage and solvents. Rapid differentiation of the Ganoderma species that are officially stated in the Chinese pharmacopoeia from easily confused Ganoderma species could be achieved based on this method, as the acquired DI-MS spectra showed that ganoderic acids, the major active components of Ganoderma, could be found only in the official Ganoderma species but not in the confused Ganoderma species. In addition, classification of wild and cultivated Ganoderma and potential differentiation of Ganoderma from different geographical locations could be accomplished based on principal component analysis (PCA) or hierarchical clustering analysis (HCA). The method is rapid, simple and reproducible, and can be further extended to analysis of other herbal medicines.