Database-aided UHPLC-Q-orbitrap MS/MS Strategy Putatively Identifies 52 Compounds from Wushicha Granule to Propose Anti-counterfeiting Quality-markers for Pharmacopoeia

Abstract

Wushicha Granule, an over-the-counter-drug (OTC) prescription, consists of 19 traditional Chinese herbals medicines (CHMs), such as Chaihu, Hongcha, Chuanxiong, Houpo, and Gancao. The five however have not been effectively characterized by the quality-markers (Q-markers) system in current Pharmacopoeia. The study therefore established a novel database-aided ultra-high performance liquid chromatography-quadrupole-orbitrap mass spectrometry (UHPLC-Q-orbitrap MS/MS) strategy. The strategy has putatively identified 52 compounds from Wushicha Granule, mainly including flavonoids, saponins, alkaloid, lignins, and lactones. Especially, saponin “glycyrrhetinic acid” in the Granule was specifically identified as 18β-configuration (rather than 18α-configuration). Meanwhile, two pairs of isomers were fully discriminated, including vitexin vs isovitexin and daidzein vs 7,4'-dihydroxyflavone. 8β-Glycyrrhetinic acid, together with saponin saikosaponin A, alkaloid caffeine, lactone S-senkyunolide A, and lignin magnolol, were further studied using quantum chemical calculation, UV-vis spectra, and anti-counterfeiting validation experiment. In the validation experiment, they have successfully recognized 6 counterfeit Wushicha Granules, by means of a LC-MS equipped extraction software. Based on these results, 8β-glycyrrhetinic acid is recommended to replace the old Q-marker “glycyrrhetinic acid”; while saikosaponin A, caffeine, S-senkyunolide A, and magnolol are recommended as new Q-markers. These recommendations can not only recognize the counterfeits regarding Chaihu, Hongcha, Chuanxiong, Houpo, and Gancao, but also prevent the possible safety-incident. All these will greatly improve the efficiency and specificity of current Pharmacopoeia.