Violae herba (Zihuadiding) is a common Chinese herbal medicine. The current Chinese Pharmacopeia (ChP) defines Viola yedoensis Makino as the sole plant origin and esculetin as its sole quality-marker (Q-marker). Esculetin, however, occurs in some counterfeits as well. This implies that current ChP criterion actually cannot recognize the counterfeits of V. yedoensis . The study thus created a specialized MS library using ultra-high-performance liquid chromatography with quadrupole-orbitrap tandem mass spectrometry (UHPLC- Q -Orbitrap-MS/MS) analysis. Through library-comparison, 36 compounds were putatively identified from V. yedoensis ; especially, four isomers were successfully distinguished, that is, vitexin vs isovitexin and schaftoside vs isoschaftoside. The subsequent UHPLC- Q -Orbitrap-MS/MS semi-quantification suggested that the chemical contents of 36 compounds varied from 0.001 to 1.958% and the old Q-marker esculetin had high content (0.484 ± 0.028%). According to the relevant principles, flavonoid luteolin was proposed as the new and additional Q-marker. The proposal offers a preliminary evidence to recognize seven adulterations (or counterfeits) of V. yedoensis .
Jian Xu,Xiangdong Wang,Huijuan Yu,Xin Chai,Min Zhang,Hong-Hua Wu,Yuefei Wang
Chebulae Fructus (CF) is known as one of the richest sources of hydrolyzable tannins (HTs). In this study, ultra-performance liquid chromatography coupled with a photodiode array detector method was established for simultaneous determination of the 12 common phenolcarboxylic and tannic constituents (PTCs). Using this method, quantitative analysis was accomplished in CF and other four adulterants, including Terminaliae Belliricae Fructus, Phyllanthi Fructus, Chebulae Fructus Immaturus, and Canarii Fructus. Based on a quantitative analysis of the focused compounds, discrimination of CF and other four adulterants was successfully accomplished by hierarchical cluster analysis and principal component analysis. Additionally, the total contents of the 12 compounds that we focused on in this study were unveiled as 148.86 mg/g, 96.14 mg/g, and 18.64 mg/g in exocarp, mesocarp, and endocarp and seed of CF, respectively, and PTCs were witnessed to be the most abundant in the exocarp of CF. Noticeably, the HTs (chebulagic acid, chebulanin acid, chebulinic acid, and punicalagin) were observed to be ultimately degraded to chebulic acid, gallic acid, and ellagic acid during sunlight-drying of the fresh fruits. As a result, our study indicated that CF and its adulterants could be distinguished by the observed 12 PTCs, which were mainly distributed in the exocarp of the fruits. The HTs were prone to degrade into the three simple phenolcarboxylic acids during drying or processing, allowing us to obtain a more comprehensive understanding of the PTCs, with great significance in the improved quality of CF and related products.