Case study of Allii Macrostemonis Bulbus: From chemical and metabolic profile to quality control by UPLC/Q-TOF-MS

Allii Macrostemonis Bulbus (AMB, named Xiebai in China) is a traditional Chinese medicine with medicinal values for the treatment of thoracic obstruction and cardialgia, and also a food additive. However, due to lack of available researches, the effective material of AMB still remains unknown and there is even no quantitative standard for AMB recorded in the current edition of Chinese Pharmacopeia. In this study, we successfully investigate the chemical and metabolic profiles of AMB by ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS) using a “representative structure based homologous xenobiotics identification” strategy, which was proposed to address the challenges in complex chemical components and in vivo xenobiotics in our previous study. As a result, a total of 98 chemical components and 94 in vivo xenobiotics identified or tentatively characterized in AMB and its rat biosamples, respectively. To better understand metabolic characteristics, five representative single steroidal saponins were selected to investigate metabolite profiles. In addition, metabolic feature of saponins in AMB involved deglycosylation, glucuronidation, oxidation and dehydrogenation was proposed. Based on chemical and metabolic profile, fifty-four components were defined as quantitative markers for quality evaluation of AMB. The intra-day and inter-day precision test were less than 3.39% and 2.86%, respectively. The repeatability, stability and recovery tests were all satisfactory. Furthermore, the validated method was successfully applied to evaluate the quality of multiple samples on the market. Among them, fifteen components were performed with exact quantification, while other thirty-nine components were conducted with semi-quantification based on peak area. Taken together, our above study contributed to combining chemical and metabolic profile of AMB with multiple components quantitative analysis-based quality control method. Moreover, it would provide an evaluable example for the improvement of quality control of TCM on basis of the discovery of effective components.