Quantitative and fingerprint analysis of proanthocyanidins and phenylpropanoids in Cinnamomum verum bark, Cinnamomum cassia bark, and Cassia twig by UPLC combined with chemometrics

Cinnamomum verum and Cinnamomum cassia are widely used as spice and herbal medicine around the world. However, it is challenging to differentiate and make a quality evaluation for both Cinnamomum types due to their similarities in morphological features and general chemical composition using traditional analytical methods. In this study, a simple and efficient method was developed for the comprehensive evaluation of the two Cinnamomum, together with Cassia twig, by combining UPLC fingerprint analysis combined with quantitative analysis using two internal standards for the determination of multiple components (TSDMC). The content of 9 components (procyanidin B2, cinnamtannin B1, coumarin, 2-hydroxycinnamaldehyde, cinnamyl alcohol, cinnamic acid, cinnamaldehyde, 2'-methoxycinnamaldehyde, and eugenol) in samples was determined using reliable relative conversion factor factors that were obtained using procyanidin B2 and cinnamic acid as two internal reference standards. The quantitative results combined with chemometrics analysis were employed to identify these samples. This simple and reproducible method revealed great differences among the three Cinnamomum in their chemical composition and provides a promising method for accurate differentiation and quality evaluation for the three Cinnamomum.