Artemisia selengensis Leaves, a Vegetable Waste: LC‐MS‐Based Chemical Profiling, Ultrasound‐Assisted DES Extraction, and Xanthine Oxidase Inhibitory Activity

ABSTRACT Artemisia selengensis is a medicinal and edible plant, whose tender stems are widely consumed as a folk vegetable in China. However, due to their bitterness, Artemisia selengensis leaves (ASL) are often discarded as a waste material, resulting in resource wastage. This study aimed to characterize ASL's chemical composition, develop a “green” extraction method, and explore its potential bioactivity. Using LC‐MS, 72 compounds were identified. To extract 7 representative caffeoylquinic acids (CQAs), the mixture of choline chloride and ethylene glycol (1:6) was selected as the optimal deep eutectic solvent (DES), and the extraction parameters were optimized as follows: extraction time of 21 min, temperature of 44°C and ultrasonic power of 420 W. Based on molecular docking analysis, both 3,5‐diCQA and 1,5‐diCQA exhibited strong binding affinity to xanthine oxidase (XO), consistent with their potent XO inhibitory effects (IC 50 = 3.69 and 3.35 nmol/mL, respectively). In addition, a greater XO inhibition was observed for the DES extract (IC 50 = 6.05 μg/mL) compared with the methanol extract (IC 50 = 22.5 μg/mL). This study not only helps to reduce ASL disposal's environmental load and boost its agricultural value, but also sets a green model for similar vegetable waste to aid circular agriculture.