title: Efficient scavenging of β-carotene radical cations by antiinflammatory salicylates.
abstract: The radical cation generated during photobleaching of β-carotene is scavenged efficiently by the anion of methyl salicylate from wintergreen oil in a second-order reaction approaching the diffusion limit with k2 = 3.2 × 10(9) L mol(-1) s(-1) in 9 : 1 v/v chloroform-methanol at 23 °C, less efficiently by the anion of salicylic acid with 2.2 × 10(8) L mol(-1) s(-1), but still of possible importance for light-exposed tissue. Surprisingly, acetylsalicylate, the aspirin anion, reacts with an intermediate rate in a reaction assigned to the anion of the mixed acetic-salicylic acid anhydride formed through base induced rearrangements. The relative scavenging rate of the β-carotene radical cation by the three salicylates is supported by DFT-calculations.
authors: Department of Chemistry, Renmin University of China, Beijing 100872, China. chenghonghappyok@163.com rliang06@ruc.edu.cn ruiminhan@chem.ruc.edu.cn jpzhang@chem.ruc.edu.cn.
authors: Hong
authors: H
authors: Cheng
authors: Ran
authors: R
authors: Liang
authors: Rui-Min
authors: RM
authors: Han
authors: Jian-Ping
authors: JP
authors: Zhang
authors: Leif H
authors: LH
authors: Skibsted
mesh_terms: D000893:Anti-Inflammatory Agents / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry*; D007700:Kinetics; D009822:Oils, Volatile / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D012459:Salicylates / Q000737:chemistry*; D019207:beta Carotene / Q000737:chemistry*
chemical_list: D000893:Anti-Inflammatory Agents; D016166:Free Radical Scavengers; D005609:Free Radicals; D009822:Oils, Volatile; D010936:Plant Extracts; D012459:Salicylates; D019207:beta Carotene; C515973:wintergreen oil; C033069:methyl salicylate