Polyphenols and Antioxidant Activity of Artemisia argyi （Qichun） in Different Storage Years

Qiai from 2017 to 2020 were used as the test material, the contents of total phenolics and total flavonoids were determined by Folin-phenol method and aluminum nitrate colorimetry, respectively.Meanwhile, the composition of polyphenols was analyzed by high performance liquid chromatography（HPLC） and the antioxidant activities were evaluated by DPPH and ABTS free radical scavenging capacity, in order to provide reference for the development, utilization and quality formation of Qiai.The results showed that, the total phenolics and flavonoids contents of Qiai from 2018 was the highest, which were 50.60 GAE mg·g^-1 and 118.68 GAE mg·g^-1 respectively.Five polyphenols, 5-caffeoylquinic acid, 3-caffeoylquinic acid, 4-caffeoylquinic acid, 3,4-di-O-caffeoylquinic acid and 4,5-di-Ocaffeoylquinic acid were identified by HPLC,and 3,4-di-O-caffeoylquinic acid was the highest.The antioxidant activity of Qiai extract from 2018 was the best, and the EC₅₀ values of DPPH and ABTS free radicals were 18.43 and 0.37 μg·mL^-1,respectively.Among the five phenolic components, 3-caffeoylquinic acid had the strongest ability to scavenge DPPH and ABTS free radicals, and 3,4-di-O-caffeoylquinic acid contributed the most to the antioxidant activity of Qiai extract, about 62%-69% of the total antioxidant capacity.The polyphenols and antioxidant activities of Qiai in different storage years were different, and the quality of Qiai from 2018 was better.