Geographical Discrimination of Curcuma longa L. in Vietnam Based on LC-HRMS Metabolomics

Curcuma longa L. has been used as a food, cosmetic, traditional medicine, and natural dye for a long time in tropical and subtropical regions such as India, China, and Vietnam. Curcuminoids are considered the main bioactive compounds in this plant. This study focuses on metabolites profiling of the rhizome methanolic extract of C longa samples collected in 6 different provinces in Vietnam using liquid chromatography coupled with high-resolution mass spectrometry. The partial least-squares discriminant analysis model was then established to discriminate its metabolomes and identify the chemomarkers that help to distinguish C longa from 6 geographical locations. Consequently, collected samples were segregated into 3 main groups: northern (Lang Son, with typical content of 2 terpenoids), center (Nghe An), and southern highland (Lam Dong, with distinctive profile of 3 curcuminoids). The absolute curcuminoids' amount was also measured based on the calibration curve of reference standards. The differential metabolites including curcumin, demethoxycurcumin, and bisdemethoxycurcumin were found with the highest range in samples from Lang Son, indicating the excellent quality of turmeric cultivated in this area.