title: Radical-scavenging activity of natural methoxyphenols vs. synthetic ones using the induction period method.
abstract: The radical-scavenging activities of the synthetic antioxidants 2-allyl-4-X-phenol (X = NO2, Cl, Br, OCH3, COCH3, CH3, t-(CH3)3, C6H5) and 2,4-dimethoxyphenol, and the natural antioxidants eugenol and isoeugenol, were investigated using differential scanning calorimetry (DSC) by measuring their anti-1,1-diphenyl-2-picrylhydrazyl (DPPH) radical activity and the induction period for polymerization of methyl methacrylate (MMA) initiated by thermal decomposition of 2,2'-azobisisobutyronitrile (AIBN) and benzoyl peroxide (BPO). 2-Allyl-4-methoxyphenol and 2,4-dimethoxy-phenol scavenged not only oxygen-centered radicals (PhCOO*) derived from BPO, but also carbon-centered radicals (R*) derived from the AIBN and DPPH radical much more efficiently, in comparison with eugenol and isoeugenol. 2-Allyl-4-methoxyphenol may be useful for its lower prooxidative activity.
authors.affiliation: Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan. y-kadoma.fm@tmd.ac.jp
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kadoma
authors.forename: Toshiko
authors.initials: T
authors.lastname: Atsumi
authors.forename: Norihisa
authors.initials: N
authors.lastname: Okada
authors.forename: Mariko
authors.initials: M
authors.lastname: Ishihara
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yokoe
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Fujisawa
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D001585:Benzoyl Peroxide / Q000737:chemistry / Q000378:metabolism; D001713:Biphenyl Compounds / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D005054:Eugenol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006834:Hydrazines / Q000737:chemistry; D020366:Methylmethacrylate / Q000494:pharmacology*; D009570:Nitriles / Q000737:chemistry / Q000378:metabolism; D010851:Picrates; D011748:Pyrogallol / Q000031:analogs & derivatives* / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D006834:Hydrazines; D009570:Nitriles; D010851:Picrates; D017382:Reactive Oxygen Species; D011748:Pyrogallol; D020366:Methylmethacrylate; D005054:Eugenol; C010120:pyrogallol 1,3-dimethyl ether; C036643:isoeugenol; C004931:1,1-diphenyl-2-picrylhydrazyl; C004526:azobis(isobutyronitrile); D001585:Benzoyl Peroxide