“…In the present study, 1 H-NMR analyses were carried out to characterize and quantify major metabolites in authenticated cinnamon species, i.e., CV, CA, and CI, and commercial products. Signal assignments were further confirmed using 2D-NMR experiments, including 1 H-1 H COSY (correlation spectroscopy), 1 H- 13 C HSQC (heteronuclear single quantum coherence spectroscopy), and 1 H- 13 C HMBC (heteronuclear multiple bond correlation). Two main regions appeared in the 1 H-NMR spectra (Figure 4): an up-field region (δ H 0.5 to 5.5 ppm) belonging mostly to primary metabolites, namely, fatty acids (N1), glycerol (N2), and sugars (N3-N6) and a down-field region (δ H 5.5-9.5 ppm) assigned to secondary metabolites, i.e., cinnamic acids (N7-N8), cinnamaldehydes (N9-N11), protocatechuic acid (N12) and coumarin (N13).…”