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.
Given the safety of synthetic antioxidants, people are increasingly inclined to develop and use natural antioxidants. However, rapid screening and identification of active ingredients from the complex systems of natural products is one of the major challenges for the modernization of traditional Chinese medicine. In this study, online extraction-high performance liquid chromatography-diode array detection-quadrupole time-of-flight mass spectrometry coupled with ABTS antioxidant assay (OLE-HPLC-DAD-QTOF-MS/MS-ABTS), in which sample preparation, separation, detection and antioxidant assay were integrated in a single step, was used to rapidly identify antioxidant components from the different parts of Citrus reticulata , including its peels, leaves, vascular bundies and seeds. After method validation (system adaptability, extraction yield and repeatability), the four samples of different botanical parts were analyzed. As a result, among 49 found chromatographic peaks, 33 peaks displayed varying degrees of antioxidant activity and 39 peaks were tentatively or unambiguously identified based on their retention time, UV spectrum and mass spectrometry information and the comparison with reference substance and data in literature, including 10 phenolic acids, 9 polymethoxy flavonoids, 7 flavonoid- O -glycosides and 13 other ingredients. It is concluded that the established method is simple, fast, and reliable, which not only saves the materials and solvents as well as time, but also reduces the risk of degradation of chemical components during the extraction process, suitable for rapid screening and identification of antioxidant components of complex mixture.
危险品化学品经营许可证（带存储）