Comprehensive characterization and identification of antioxidants in Folium Artemisiae Argyi using high-resolution tandem mass spectrometry

Antioxidants from natural sources, such as vegetables and fruits, are attracting more and more interest. In this work, we evaluated the antioxidant potential of Folium Artemisia Argyi, a traditional Chinese herb medicine and food supplement. The total phenolic content, total flavonoid content, and antioxidant ability of the crude extracts and fractions obtained from consecutively partition of n-hexane, ethyl acetate, and n-butanol were measured and compared. Ethyl acetate fraction shows the highest total phenolic and flavonoid contents and highest antioxidant capability with regard to DPPH, ABTS, superoxide anion free radical scavenging ability, and ferric-reducing antioxidant power. In addition, the potential antioxidant components were screened by DPPH-UHPLC-MS experiments and subsequently characterized by using high-resolution tandem mass spectrometry. This work finally identified 45 antioxidants, including organic acids, phenolic compounds, flavonoids, and methoxylated flavonoids. The results suggested that Folium Artemisiae Argyi is a potential inexpensive resource of natural antioxidants.