Antiphoto-oxidative activity of sesamol in methylene blue- and chlorophyll-sensitized photo-oxidation of oil.
The effects and mechanism of sesamol on the methylene blue- or chlorophyll-sensitized photo-oxidations of soybean oil have been studied. Sesamol showed strong antiphoto-oxidative activity in both methylene blue-and chlorophyll-sensitized photo-oxidations of soybean oil in a dose-dependent manner. The 1.0 x 10(-3) M sesamol treatments showed 84.7 and 43.4% inhibitions of methylene blue- and chlorophyll-sensitized photo-oxidations of soybean oil in methylene chloride. The antiphoto-oxidative activity of sesamol was comparable to that of delta-tocopherol in both methylene blue- and chlorophyll-sensitized photo-oxidations, at the same molar basis. Sesamol effectively inhibited rubrene oxidation with a chemical source of singlet oxygen in microemulsion, showing its strong singlet oxygen quenching ability. The results suggested that the antiphoto-oxidative activity of sesamol in the photo-oxidation of oil was, at least in part, due to its singlet oxygen scavenging activity. The singlet oxygen quenching rate constant (k(ox-Q) + k(q)) of sesamol was determined to be 1.9 +/- 0.3 x 10(7) M(-1) s(-1). This represents the first report on the antiphoto-oxidative activity of sesamol in the sensitized photo-oxidation of oil, and its bimolecular singlet oxygen quenching ability.
Department of Food Science and Technology, Woosuk University, Samrea-Up, Wanju-Kun, Jeonbuk Province 565-701, Republic of Korea.
Joo Yeon
JY
Kim
Dong Seong
DS
Choi
Mun Yhung
MY
Jung
D000975:Antioxidants / Q000494:pharmacology*; D052117:Benzodioxoles; D002734:Chlorophyll / Q000494:pharmacology*; D004655:Emulsions; D008027:Light; D008751:Methylene Blue / Q000494:pharmacology*; D009279:Naphthacenes / Q000737:chemistry; D010084:Oxidation-Reduction; D010636:Phenols / Q000494:pharmacology*; D010777:Photochemistry; D026082:Singlet Oxygen / Q000737:chemistry; D013024:Soybean Oil / Q000737:chemistry*
D000975:Antioxidants; D052117:Benzodioxoles; D004655:Emulsions; D009279:Naphthacenes; D010636:Phenols; D002734:Chlorophyll; D026082:Singlet Oxygen; C045049:rubrene; D013024:Soybean Oil; C025583:sesamol; D008751:Methylene Blue