Analysis of Antioxidants from Three Parts of <i>Polygonum Chinense</i> based on Online Extraction High Performance Liquid Chromatography Antioxidant Analysis System

In the current study, a rapid online extraction combined with high-performance liquid chromatography (HPLC) antioxidant analysis approach was developed to explore the antioxidant ingredients in three different parts of Polygonum Chinense. A total of 22 chromatographic peaks were found, among which 8 components were found for the first time. And among these 22 peaks, 19 of them were demonstrated as antioxidants. Furthermore, all three parts from Polygonum Chinense exhibited antioxidant activity (13.19, 3.89, and 19.85 mg CE/g extract, for the leaf, stem, and flower, respectively) and the antioxidant activity values of the leaf and flower were more than 3 times that of the stem. The leaf, flower, and stem of Polygonum Chinense had 17, 13, and 15 antioxidant components, respectively. Among them, neochlorogenic acid (2) and quercetin-3-O-malonylglucoside (18) were considered as the main antioxidants in the leaf of Polygonum Chinense. In terms of flower, geraniin (10) and quercetin-3-O-malonylglucoside (18) were proved as the major antioxidants. This is the first report on the antioxidant components from different parts of Polygonum Chinense. It provides foundational scientific data for the continued exploration of chemical and pharmacological study of Polygonum Chinense, which is beneficial for the future product development and quality evaluation improvement of Polygonum Chinense.