Macamides and macaenes are two kinds of secondary metabolites in Lepidium meyenii (Maca). Geographical origin has an important effect on accumulation of active components in Maca. Hence, it is feasible to differentiate Maca from different origins according to the type and content of macamides and macaenes. Using petroleum ether as solvent, macamides and macaenes were extracted from Maca cultivated in Yunnan province, China (Qujing, Lijiang and Shangri-La) and Cerro de Pasco in central Peru, respectively. Then, these extracts were purified by silica gel column eluted with petroleum ether and analyzed qualitatively and quantitatively by UPLC/MS. Based on the fact that macamides and macaenes are characteristic components in Maca, the contents of them were used as principal components to successfully differentiate these Maca combined with PCA. The result suggests that based on remarkable difference of the content of macamides and macaenes in Maca from these four origins, PCA can be used to differentiate these Maca successfully. This strategy can be applied to evaluate quality and identify origins of other natural products.
Yan et al. (Fri,) studied this question.