Objective: This study was aimed to apply metabolite fingerprinting for the authentication of Curcuma xanthorrhiza adulterated with Zingiber cassumunar using 1H-NMR spectroscopy and multivariate analysis (chemometrics) methods, namely principal component analysis (PCA) and partial least square–discriminant analysis (PLS-DA).
Methods: The pure dried powder samples of C. xanthorrhiza from different regions, Z. cassumunar, and its binary mixtures of C. xanthorrhiza with various concentrations of Z. cassumunar as adulterants were prepared for 1H-NMR measurements. The binary mixtures were prepared by mixing C. xanthorrhiza with various concentrations (10%, 25%, 40%, 50%, and 75%) of Z. cassumunar. 1H-NMR spectra were subjected to multivariate analysis for classification using PCA and PLS-DA.
Results: A diverse group of metabolites could be detected by 1H-NMR spectroscopy. PCA using the chemical shift in 1H-NMR spectra of the plant extracts as variables clearly discriminated pure C. xanthorrhiza extracts from different origins and C. xanthorrhiza extract adulterated with Z. cassumunar. PLS-DA employed to enhance the separation obtained from the PCA model resulted in well separation and good classification of pure C. xanthorrhiza from the adulterated ones.
Conclusion: The developed method could be a useful and powerfull tools to assess adulteration practice and to evaluate the authentication of C. xanthorrhiza extracts.
Metabolic responses of willow (Salix purpurea L.) leaves to mycorrhization as revealed by mass spectrometry and 1H NMR spectroscopy metabolite profiling