Evaluation of phytochemicals in Agastache rugosa (Fisch. & C.A.Mey.) Kuntze at different growth stages by UPLC-QTof-MS

To improve the utility of A. rugosa as a seasonal edible vegetable, it is necessary to determine the components and contents of reference substances during its different growth stages. Standard markers were characterized as six compounds including a new compound 5 (acacetin 2″-O-acetyl-6″-O-malonyl-β-d-glucopyranoside) by NMR and UPLC-QTof-MS analyses. A method for qualitative/quantitative analysis of the extract was evaluated including compounds (3-5), which are easily converted to tilianin (2) during extraction & isolation process by using UPLC-QTof-MS. The contents of each compound were remarkably changed at different growth stages, especially tilianin group (2-4, and 5), which were the predominant substances (>95%) in all stages. Additionally, more comprehensive chemical information, including the relative retention time, peak area and contents, were obtained simultaneously from the raw material using marker compounds. Therefore, application of this analysis method may relieve the increasing demand for pure standards.