Polarity-extended composition profiling via LC-MS-based metabolomics approaches: A key to functional investigation of Citrus aurantium L

Citrus is a genus containing diverse edible species, among them Citrus aurantium L. is widely utilized while short of composition research. Herein, utilizing multiple liquid chromatography-mass spectrometry (LC-MS)-based metabolomics approaches, we comprehensively characterized its components. We first systematized both LC and MS characteristics of polymethoxyflavones (PMFs), by which 13 PMFs were identified in C. aurantium, and their biosynthesis pathway was further established. Using derivatization-LC-MS targeted metabolomics approaches, 28 carbohydrates and 18 carboxylic acids were firstly found in C. aurantium. Combined with untargeted metabolomics method, total 147 compositions were characterized, among which 92 were firstly reported in C. aurantium. We further obtained their geographical features and sought out principal discriminative compounds. Moreover, typical biofunctions of C. aurantium from diverse regions were speculated using pharmacological platform and partly verified by experiments. The present study provided systematic component information for C. aurantium, which laid the foundation for its further exploitation as functional food.