Kinetics and Mechanism for the Scavenging Reaction of the 2,2-Diphenyl-1-picrylhydrazyl Radical by Synthetic Artepillin C Analogues

DOI PDF Web Site 4 Citations 41 References
  • Kawashima Tomonori
    Radio-Redox-Response Research Team, Advanced Particle Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS)
  • Manda Sushma
    Radio-Redox-Response Research Team, Advanced Particle Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS)
  • Uto Yoshihiro
    Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima
  • Ohkubo Kei
    Department of Material and Life Science, Graduate School of Engineering, Osaka University ALCA, Japan Science and Technology Agency (JST)
  • Hori Hitoshi
    Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima
  • Matsumoto Ken-ichiro
    Radio-Redox-Response Research Team, Advanced Particle Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS)
  • Fukuhara Kiyoshi
    Division of Organic Chemistry, National Institute of Health Sciences (NIHS)
  • Ikota Nobuo
    School of Pharmacy, Shujitsu University
  • Fukuzumi Shunichi
    Department of Material and Life Science, Graduate School of Engineering, Osaka University ALCA, Japan Science and Technology Agency (JST) Department of Bioinspired Science, Ewha Womans University
  • Ozawa Toshihiko
    Department of Health Pharmacy, Yokohama College of Pharmacy
  • Anzai Kazunori
    School of Pharmaceutical Sciences, Nihon Pharmaceutical University
  • Nakanishi Ikuo
    Radio-Redox-Response Research Team, Advanced Particle Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS)

Bibliographic Information

Other Title
  • Kinetic and mechanism for the scavenging reaction of the 2,2-diphenyl-1-picrylhydrazyl radical by synthetic artepillin C analogues

Search this article

Description

The kinetics for the reaction of the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) with artepillin C, a prenylated phenylpropanoid found specifically in Brazilian propolis, and its analogues was examined in deaerated acetonitrile (MeCN) to shed light on the mechanism for the radical-scavenging reaction of phenolic antioxidants as well as on the structure–activity relationship. Among the examined analogues, a compound having a catechol moiety is found to have the largest second-order rate constant (k) for the DPPH•-scavenging reaction. The deuterium kinetic isotope effect of 1.6 was observed for the DPPH•-scavenging reaction of artepillin C in the presence of 0.13 M CD3OD or CH3OH in deaerated MeCN at 298 K. The log k values were found to be linearly correlated with calculated energy difference values (DHT, HT: hydrogen transfer) between the artepillin C analogues and the corresponding phenoxyl radicals, while such a linear correlation cannot be observed between the log k values and calculated ionization potentials (IP), DHT − IP, or experimental one-electron-oxidation potentials of the artepillin C analogues. These results together with a calculated structure of the transition state for the reaction between the artepillin C analogue and DPPH• suggest that the DPPH•-scavenging reaction of the artepillin C analogues in deaerated MeCN proceeds via a one-step hydrogen-atom transfer from the phenolic OH group to DPPH• rather than an electron transfer followed by proton transfer.

Journal

Citations (4)*help

See more

References(41)*help

See more

Related Projects

See more

Details 詳細情報について

Report a problem

Back to top