• <small id="eqkgy"><blockquote id="eqkgy"></blockquote></small>
    <input id="eqkgy"><samp id="eqkgy"></samp></input>
  • <kbd id="eqkgy"><strong id="eqkgy"></strong></kbd><option id="eqkgy"></option>
  • <samp id="eqkgy"><label id="eqkgy"></label></samp>
  • <u id="eqkgy"></u>
  • 歡迎訪問云南西力生物技術股份有限公司!證券代碼:871574
    首頁 成 果 源于西力產品的客戶論文
    Antioxidant Mechanisms of Echinatin and Licochalcone A. Molecules, 2019, 24: 3.
    發布時間:2019-04-24 閱讀數:1026 來源:Molecules
    分享到:

    Abstract:

    Echinatin and its 1,1-dimethyl-2-propenyl derivative licochalcone A are two chalcones found in the Chinese herbal medicineGancao. First, their antioxidant mechanisms were investigated using four sets of colorimetric measurementsin this study. Three sets were performed in aqueous solution,namely Cu(2+)-reduction, Fe(3+)-redution, and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO●)-scavenging measurements,while 1,1-diphenyl-2-picrylhydrazyl radical (DPPH●)-scavenging colorimetric measurements were conducted in methanol solution. The four sets of measurements showed that the radical-scavenging (or metal-reduction) percentages for both echinatin and licochalcone A increased dose-dependently. However, echinatin always gave higher IC50values than licochalcone A. Further, each product of the reactions of the chalcones with DPPH●was determined using electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS). The UPLC-ESI-Q-TOF-MS/MS determination for echinatin yielded several echinatin–DPPH adduct peaks (m/z 662, 226, and 196) and dimeric echinatin peaks (m/z 538, 417, and 297). Similarly, that for licochalcone A yielded licochalcone A-DPPH adduct peaks (m/z 730, 226, and 196) and dimeric licochalcone A peaks (m/z 674 and 553). Finally, the above experimental data were analyzed using mass spectrometry data analysis techniques, resonance theory, and ionization constant calculations. It was concluded that, (i) in aqueous solution, both echinatin and licochalcone A may undergo an electron transfer (ET) and a proton transfer (PT) to cause the antioxidant action. In addition, (ii) in alcoholic solution, hydrogen atom transfer (HAT) antioxidant mechanisms may also occur for both. HAT may preferably occur at the 4-OH, rather than the 4′-OH. Accordingly, the oxygen at the 4-position participates in radical adduct formation (RAF). Lastly, (iii) the 1,1-dimethyl-2-propenyl substituent improves the antioxidant action in both aqueous and alcoholic solutions.


    ewm.jpg 微信公眾號
    11.jpg 移動官網
    特別聲明:禁止在未經同意情況下轉載本網站信息,BioBioPha品牌產品均由西力生物獨家生產與銷售,僅用于科學研究或企業研發!
    版權所有 2019-2020 云南西力生物技術股份有限公司 BioBioPha 滇ICP備09000810號-1滇公安備案號 53019002000069號
    技術支持:奧遠科技

    聯系客服

  • <small id="eqkgy"><blockquote id="eqkgy"></blockquote></small>
    <input id="eqkgy"><samp id="eqkgy"></samp></input>
  • <kbd id="eqkgy"><strong id="eqkgy"></strong></kbd><option id="eqkgy"></option>
  • <samp id="eqkgy"><label id="eqkgy"></label></samp>
  • <u id="eqkgy"></u>
  • av无码一区二区三区_桃花视频免费观看在线完整版_欧美人与拘牲交大全o人禾_av片在线观看无码免费