UPLC-Q-TOF-MS With Chemometrics Approach Analysis of Nonvolatile Compounds for Medicinal Citrus reticulata With Cultivar and Areas Variations

Introduction: Citri Reticulatae Pericarpium (CRP), also known as Chenpi in Chinese, is the dry mature peel of Citrus reticulata Blanco or its cultivated varieties. CRP as the health-care food and dietary supplement has been widely used in various diseases. The quality of CRP can be affected by various factors, which are closely related to the metabolite composition of CRP.

Objectives: The objective of this study is to conduct a comprehensive comparative analysis on the chemical profiling of 51 C. reticulata samples of eight medicinal varieties, grown in different areas, and provide a methodological reference for the study of pharmacodynamic material bases and quality control of C. reticulata.

Methodology: Initially, a comprehensive characterization was performed using quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS), and a heatmap visualization was employed for clarifying the distribution of the annotated active ingredients. Furthermore, obtained chemical profiles data were employed in multivariate statistical methods, comprising principal component analysis (PCA), and orthogonal partial least-squares-discrimination analysis (OPLS-DA).

Results: A total of 42 chemical components were annotated in positive ion mode. The relative contents were evident differences in the active ingredients of medicinal varieties of C. reticulata; mostly, polymethoxy flavones (PMFs) in C. reticulata "Dahongpao" were more abundant; among them, nobiletin and tangeretin are the main active ingredients in CRP. In addition, the relative contents of chemical constituents of C. reticulata "Dahongpao" and C. reticulata "Unshiu" from different areas were less variable. Compared with production origins, the varieties of C. reticulata had a greater impact on quality.

Conclusion: This work obtains a better understanding of the chemical profiles of medicinal varieties of C. reticulata, facilitated the reasonable applicability and quality control of medicinal varieties of C. reticulata.