Snow chrysanthemum ( Coreopsis tinctoria Nutt.), a world-widely well-known flower tea material, has attracted more and more attention because of its beneficial health effects such as antioxidant activity and special flavor. In this study, a high performance liquid chromatography coupled with diode array detection and mass spectrometry (HPLC-DAD-MS) and 2,2′-azinobis(3-ethylbenzthiazoline-sulfonic acid)diammonium salt (ABTS) based assay was employed for comparison and identification of antioxidants in different samples of snow chrysanthemum. The results showed that snow chrysanthemum flowers possessed the highest while stems presented the lowest antioxidant capacities. Fourteen detected peaks with antioxidant activity were temporarily identified as 3,4′,5,6,7-pentahydroxyflavanone-O-hexoside, chlorogenic acid, 2R-3′,4′,8-trihydroxyflavanone-7-O-glucoside, flavanomarein, flavanocorepsin, flavanokanin, quercetagitin-7-O-glucoside, 3′,5,5′,7-tetrahydroxyflavanone-O-hexoside, marein, maritimein, 1,3-dicaffeoylquinic acid, coreopsin, okanin and acetyl-marein by comparing their UV spectra, retention times and MS data with standards or literature data. Antioxidants existed in snow chrysanthemum are quite different from those reported in Chrysanthemum morifolium , a well-known traditional beverage in China, which indicated that snow chrysanthemum may be a promising herbal tea material with obvious antioxidant activity.
Context Coreopsis tinctoria Nutt (Asteraceae), named snow chrysanthemum, is known to have a high level of polyphenols. However, the potential prebiotic effect on modulating intestinal microflora is still unclear.Objective The chemical composition, antioxidant properties of snow chrysanthemum polyphenols (SCPs) and their effects on human intestinal microbiota were investigated.Materials and methods SCPs were extracted using ultrasonic-assisted extraction, and further determined using UPLC-QE Orbitrap/MS. Five assays were used to investigate the antioxidant activities of SCPs. Subsequently, the effects of SCPs on intestinal microbiota in vitro were determined by high throughput sequencing and bioinformatics analysis.Results Marein, isookanin and cymaroside were the major phenolic compounds, which accounted for 42.17%, 19.53% and 12.25%, respectively. Marein exhibited higher scavenging capacities in DPPH (EC50 = 8.84 µg/mL) and super anion radical assay (EC50 = 282.1 µg/mL) compared to cymaroside and isookanin. The antioxidant capacity of cymaroside was weakest among the three phenolic compounds due to the highest EC50 values, especially for superoxide anion radical assay, EC50 > 800 µg/mL. The result of in vitro fermentation showed that the three phenolic compounds increased the relative abundances of Escherichia/Shigella, Enterococcus, Klebsiella, etc., and isookanin notably increased the relative abundance of Bifidobacterium and Lactobacillus.Discussion and conclusions SCPs exhibited antioxidant properties and potential prebiotic effects on modulating the gut microbiota composition. The findings indicated that SCPs consumption could exert prebiotic activity that is beneficial for human health.
危险品化学品经营许可证（带存储）