Extraction and Identification of Antioxidant Ingredients from Cyclocarya paliurus (Batal.) Iljinsk Using UHPLC-Q-Orbitrap-MS/MS-Based Molecular Networking

Cyclocarya paliurus (Batal.) Iljinskaja (LCP) leaves have been widely employed in food and traditional medicine for treating hyperlipidaemia and its complications, possibly owing to their antioxidant properties. The aim of the present study is to identify the chemical ingredients of antioxidant extracts from LCP by using UHPLC-Q-Orbitrap-MS/MS-based molecular networking, a very recent and useful tool for annotation of chemical constituents in mixtures. The extraction conditions of antioxidant extracts from LCP were optimised by single-factor analysis and response surface methodology (RSM). The optimised conditions were a methanol concentration of 32%, a liquid-to-solid ratio of 0.4 ml/mg, an extraction temperature of 25 degrees C, and an extraction time of 32 min. Under these conditions, the antioxidant yield was 516.20 +/- 28.52 mu mol TE/ml. The main active ingredients in the antioxidants were identified by UHPLC-Q-Exactive Orbitrap-MS-based molecular networking. In total, 42 compounds were identified, including 20 flavonoids, 16 quinic acid derivatives, 4 caffeoyl derivatives, and 2 coumaroyl derivatives. The findings of the present work suggest that LCP could be a suitable source of natural antioxidant compounds, which might be applicable in the development of potential pharmaceutical drugs targeting diseases related to oxidative stress.

Automated summary

This study identified the chemical ingredients of antioxidant extracts from Cyclocarya paliurus leaves using UHPLC-Q-Orbitrap-MS/MS-based molecular networking. The optimized conditions for extraction resulted in a high antioxidant yield. A total of 42 compounds, including flavonoids, quinic acid derivatives, caffeoyl derivatives, and coumaroyl derivatives, were identified. These findings suggest that Cyclocarya paliurus could be a suitable source of natural antioxidant compounds for potential pharmaceutical drug development targeting oxidative stress-related diseases.