NMR- and MS-based multiplex approach for comparative metabolome profiling of Curcuma caesia versus curcuma longa rhizomes and in relation to in vitro biological effects

The study presents the first integrated comparative metabolomics approach of Curcuma caesia known as blue curcuma, that is relatively less explored, compared with the well-known yellow curcuma Curcuma longa using a multiplex analytical approach viz., UV, NMR, UPLC/MS/MS, GC/MS and SPME/GC/MS. The study targeted fingerprinting and chemical characterization of their primary and secondary metabolites as well as annotation of volatiles affecting their aroma and culinary uses. Datasets were further modelled using multivariate data analyses (PCA and OPLS) for samples' classification and discrimination. The study revealed several newly reported metabolites in blue curcuma and assigned discriminating biomarkers for each species i.e. sesquiterpenes in blue curcuma vs. curcuminoids in yellow curcuma. Bioactivity assays, including antioxidant and antidiabetic activities, showed moderate activity for C. caesia relative to C. longa, while both species were inactive as anti-obesity agents.