Comparison of various commercially available cinnamon barks using NMR metabolomics and the quantification of coumarin by quantitative NMR methods

Cinnamon bark is an important spice worldwide. In this study, the chemical diversity of various commercially available cinnamon barks that difered in their production areas and utility applications (culinary spice or medicines) were investigated by the use of 1 H NMR metabolomics. Our results indicated that principle component analysis (PCA) and hierarchical cluster analysis (HCA) of the 1 H NMR spectra of the cinnamon bark methanolic extracts including the deduction of their species by nucleotide sequence analysis enabled diferentiation of the cinnamon barks according to their species, production areas and utility applications. The constituents of Vietnam cinnamon were found to difer signifcantly from the other samples investigated based on PCA score plots and HCA constellation dendrograms. Coumarin was found to be a key compound for the discrimination of Vietnamese cinnamon by multivariate analysis of the 1 H NMR spectral data and direct comparison of the 1 H NMR spectra. In addition, coumarin was quantifed using quantitative NMR methods. As a result, coumarin was contained in Vietnamese cinnamon at a higher level compared to other cinnamons. This study indicated that 1 H NMR metabolomics could deduce spices, utility, and producing area of commercially available cinnamon barks. Furthermore, combining quantitative 1 H NMR methods with 1 H NMR metabolomics enable quantifcation of coumarin in cinnamon bark on a single measurement