Structural Characterization and Identification of Major Constituents in Jitai Tablets by High-Performance Liquid Chromatography/Diode-Array Detection Coupled with Electrospray Ionization Tandem Mass Spectrometry

In the present study a universally applicable HPLC-DAD/ESI-MS/MS method was developed for carrying out the comprehensive characterization of Jitai tablets (JTT). Based on the ESI-MSn fragmentation patterns of the reference standards, a total of 101 components were identified or tentatively characterized by comparing their retention times, UV and MS spectra with those of reference standards or through the matching of empirical information with those of published components in the in-house library. The characteristic fragmentation pattern of alkaloids, phenolic acids, tanshinones, flavonoid glycosides, cyanogenic glycosides, ginsenosides, 2-(2-phenylethyl) chromones, phthalides and gingerol-related compounds were tentatively elucidated using structurally-relevant product ions. It was observed that neutral losses of C9H10O3 and C9H8O2 were the characteristic product ions of scopola alkaloids. Neutral fragment mandelonitrile was the characteristic ion of cyanogenic glycosides. To our knowledge, tropylium ion and C4H2O unit were the characteristic ions of 2-(2-phenylethyl) chromone, which resulted from the Retro-Diels-Alder (RDA) cleavage of the C ring. The results indicated that the developed analysis method could be employed as a rapid, effective technique for structural characterization of chemical constituents in TCM. This work is expected to provide comprehensive information for the quality evaluation and pharmacokinetic studies of JTT.