Comparative study of lanostane-type triterpene acids in different parts of Poria cocos (Schw.) Wolf by UHPLC–Fourier transform MS and UHPLC-triple quadruple MS

Poria cocos (Schw.) Wolf is widely used as a traditional Chinese medicine, and approximately 10% of traditional Chinese medicinal preparations contain this material, according to the Chinese Pharmacopoeia (2010 edition). Although the epidermis (fulingpi in Chinese, or FLP) and the inner parts (baifuling in Chinese, or BFL) of P. cocos had different therapeutic applications in history, studies pertaining to a comparative analysis of their chemical constituents have been scarce. UHPLC-DAD-FT/MS(n) has been used in the current study to identify the triterpene acids present in fungus based on a detailed analysis of the fragmentation behavior of 13 standard compounds. This analysis allowed for the identification of 27 triterpene acids, including five groups of isomers and four potential new compounds. Furthermore, a UHPLC-MS/MS method has been developed for quantifying the amounts of nine bioactive triterpene acids in samples of the FLP and BFL, including three 3,4-seco-lanostane-type triterpene acids. These results revealed significant differences in the amounts of these compounds in the FLP and BFL samples. Principal component analysis and partial least squares discriminant analysis of the results for the FLP and BFL samples clearly demonstrated that dehydrotumulosic acid, trametenolic acid, dehydrotrametenolic acid and poricoic acid A were the main compounds contributing to the clusters in FLP and BFL. The observed differences in the chemical compositions of FLP and BFL could provide some explanation of the differences in their clinic applications. This study represents the first reported comprehensive analysis of lanostane-type triterpene acids in FLP and BFL parts of P. cocos.