title: Screening of free radical scavengers from Erigeron breviscapus using on-line HPLC-ABTS/DPPH based assay and mass spectrometer detection.
abstract: Erigeron breviscapus is a well-known traditional Chinese herbal medicine. In this study, on-line HPLC-ABTS/DPPH assay coupled with MS detection were applied to screen and identify the free radical scavengers in 70% methanol extracts of E. breviscapus. Using on-line HPLC-ABTS-MS and HPLC-DPPH-MS assay, 13 radical scavengers (including 4-O-caffeoylquinic acid (4-CQA) (1), 9-caffeoyl-2,7-anhydro-2-octulosonic acid (9-COA) (2), 3-caffeoyl-2,7-anhydro-3-deoxy-2-octulopyranosonic acid (3-CDOA) (3), erigeside I (4), quercetin-3-O-glucuronide (5), eriodictyol-7-O-glucuronide (6), scutellarin (7), 1,4-di-O-caffeoylquinic acid (1,4-di-CQA) (8), 3,5-di-CQA (9), 1-malonyl-3,5-di-CQA (10), erigoster B (11), 4,5-di-CQA (12) and 4,9-di-CDOA (13)) and 9 radical scavengers (including 1, 4, 7, 8, 9, 10, 11, 12 and 13) were discovered, respectively. Furthermore, the anti-oxidative activities of 4 compounds, including 7, 9, 11 and 12 were evaluated. Reverse anti-oxidative activity order of scutellarin and 3,5-di-CQA was observed in on-line HPLC-ABTS assay and on-line HPLC-DPPH assay. To validate their anti-oxidative activities, the off-line ABTS and DPPH assays were performed. Given sufficient reaction time, 3,5-di-CQA showed higher activity than scutellarin, which was consistent with the order obtained in on-line HPLC-ABTS assay. These results revealed that on-line HPLC-ABTS assay is a more sensitive method for screening and determining free radical scavengers, especially more suitable for those compounds with slower reaction kinetics.
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.forename: Lin-Dong
authors.initials: LD
authors.lastname: Zhang
authors.forename: Bao-Cai
authors.initials: BC
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.forename: Hua
authors.initials: H
authors.lastname: Yu
authors.forename: Jian-Bo
authors.initials: JB
authors.lastname: Wan
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: Li
mesh_terms: D052160:Benzothiazoles; D001713:Biphenyl Compounds; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004353:Drug Evaluation, Preclinical; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D049919:Erigeron / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000032:analysis / Q000302:isolation & purification*; D005609:Free Radicals; D013058:Mass Spectrometry / Q000379:methods*; D000432:Methanol; D009862:Online Systems; D010851:Picrates; D010936:Plant Extracts / Q000737:chemistry; D012680:Sensitivity and Specificity; D012997:Solvents; D013451:Sulfonic Acids
chemical_list: D052160:Benzothiazoles; D001713:Biphenyl Compounds; D004365:Drugs, Chinese Herbal; D016166:Free Radical Scavengers; D005609:Free Radicals; D010851:Picrates; D010936:Plant Extracts; D012997:Solvents; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C004931:1,1-diphenyl-2-picrylhydrazyl; D000432:Methanol