title: Screening and identification of radical scavengers from Neo-Taraxacum siphonanthum by online rapid screening method and nuclear magnetic resonance experiments.
abstract: An online rapid screening method, the high-performance liquid chromatography (HPLC)-diode array detector (DAD)-radical scavenging detection (RSD)-electrospray ionization (ESI)-mass spectroscopy (MS)/MS system, was developed for the screening and identification of radical scavengers from Neo-Taraxacum siphonanthum, a new species found in China in 1989. For further characterization, the target compounds were isolated by silica column chromatography, preparative high-performance liquid chromatography (HPLC), HSCCC, and Sephadex LH-20 column chromatography and elucidated on the basis of ultraviolet (UV), ESI-MS/MS, and nuclear magnetic resonance (NMR) spectroscopy, as well as the chemical analysis. Eighteen antioxidative polyphenols (5 caffeic acid derivatives and 13 flavonoid derivatives) were characterized from Neo-T. siphonanthum. The distribution of all compounds was discussed in a chemosystematic context, which suggested that the genera Neo-Taraxacum and Taraxacum might relate chemosystematically.
authors.affiliation: School of Chemistry and Chemical Engineering, Central South University, Changsha, P. R. China. shuyshi@gmail.com
authors.forename: Shu Yun
authors.initials: SY
authors.lastname: Shi
authors.forename: Yu Ping
authors.initials: YP
authors.lastname: Zhang
authors.forename: Hong Hao
authors.initials: HH
authors.lastname: Zhou
authors.forename: Ke Long
authors.initials: KL
authors.lastname: Huang
authors.forename: Xin Yu
authors.initials: XY
authors.lastname: Jiang
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification; D016166:Free Radical Scavengers / Q000032:analysis* / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D009862:Online Systems; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification; D059808:Polyphenols; D013045:Species Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D031205:Taraxacum / Q000737:chemistry*; D013997:Time Factors
chemical_list: D005419:Flavonoids; D016166:Free Radical Scavengers; D010636:Phenols; D059808:Polyphenols