Accumulation patterns of major bioactive components in two chemotypes of Agastache rugosa during flower development evaluated by GC-QQQ-MS/MS and UPLC-QTOF-MS/MS analyses

Agastache rugosa (AR) is a wildly cultivated medicinal and aromatic crop, which usually recommended to be harvested when the plant is exuberant with not flowering or in full flower stage. But there is no scientific basis for the support of the cognition. Therefore, the accumulation patterns of major active components during flower development (inflorescences with buds, full bloom and after full bloom stages) in two chemotypes (menthone type and estragole type) of AR were investigated by newly developed GC–QQQ–MS/MS and UPLC–QTOF–MS/MS methods. Five volatile (pulegone, menthone, estragole, methyleugenol and β-caryophyllene) and nine non-volatile components (rosmarinic acid, tilianin, acacetin 7-O-(6"-O-malonyl)-β-D-glucopyranoside, apigenin, agastachoside, isoagastachoside, acacetin 7-O-(2"-O-acetyl-6"-O-malonyl)-β-D-glucopyranoside, cirsimaritin and acacetin) in two chemotypes of AR samples at three stages were simultaneously quantified. It was found that the relatively higher contents of main volatile components were present in menthone type of AR collected at the full flower stage and in estragole type of AR at the after full bloom stage, whereas the relatively higher contents of main non-volatile components were present in menthone type of AR collected at the inflorescences with buds stage and in estragole type of AR at the after full bloom stage. Considering major active volatile and non-volatile components with higher levels, full bloom stage and after full bloom stage should be optimal harvesting time for menthone type and estragole type of AR, respectively.