Influencing factors of plant habitat, phenophase, and organ on the essential oil composition of Agastache rugosa

Abstract

Agastache rugosa (Fisch. et Mey.) O. Ktze, also known as “Suhuoxiang” (SHX), has been cultivated for more than three hundred years as a valuable aromatic edible and medicinal plant in Jiangsu Province, China. The volatile compounds of SHX from various habitats were investigated by HS-SPME-GC-MS, detecting sixty-five chemical constituents with menthone, pulegone, and estragole being the major volatile compounds. Their relative contents showed various accumulation tendencies in different growth months by GC-MS, with the relative content of menthone gradually increasing, pulegone content decreasing, as well as estragole content climbing initially before declining. This tendency was supported by quantitative experiments using samples from various habitats, which also revealed that the full-bloom stages exhibited the highest total concentrations of menthone and pulegone. The volatile composition of SHX in various plant organs differed, with palmitic acid being the main volatile component of stems, while menthone and pulegone being the core volatile components of leaves and spikes, implying that leaves and spikes should be separated from the stem to obtain higher drug contents. The current findings provide new information for SHX cultivation and applications.