title: Effects and mechanisms of eugenol, isoeugenol, coniferylaldehyde and dihydroeugenol on the riboflavin-sensitized photooxidation of α-terpinene in methanol.
abstract: The effects of eugenol, isoeugenol, coniferylaldehyde, and dihydroeugenol on the riboflavin-sensitized photooxidation of α-terpinene in methanol were studied. Riboflavin greatly accelerated α-terpinene oxidation in methanol during light illumination, resulting in two major oxidation products (p-cymene and ascaridole). The results clearly showed the involvement of Type I and II mechanisms. All the eugenols exerted strong protective activity on riboflavin sensitized photooxidation of α-terpinene. Dihydroeugenol showed the highest protective activity, followed by isoeugenol, coniferylaldehyde, and eugenol, in a decreasing order. Dihydroeugenol greatly inhibited the production of ascaridole, but showed relatively low inhibitory activity on the formation of p-cymene. The protective activity of dihydroeugenol was higher than those of BHA, BHT and sodium azide. Sodium azide, a specific singlet oxygen quencher, showed strong inhibitory activity on the formation of ascaridole, but very low inhibitory activity on the formation of p-cymene, verifying the feasibility of mechanism study with the present model system.
authors.affiliation: Department of Food and Biotechnology, Graduate School, Woosuk University, Samnye-eup, Wanju-gun, Jeonbuk 565-701, Republic of Korea.
authors.forename: Ju Yeon
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Food and Biotechnology, Graduate School, Woosuk University, Samnye-eup, Wanju-gun, Jeonbuk 565-701, Republic of Korea. Electronic address: munjung@woosuk.ac.kr.
authors.forename: Mun Yhung
authors.initials: MY
authors.lastname: Jung
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives* / Q000737:chemistry; D002083:Butylated Hydroxyanisole / Q000737:chemistry; D002084:Butylated Hydroxytoluene / Q000737:chemistry; D000081005:Cyclohexane Monoterpenes; D000081007:Cymenes; D005054:Eugenol / Q000031:analogs & derivatives* / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry; D039821:Monoterpenes / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry; D012256:Riboflavin / Q000737:chemistry*; D026082:Singlet Oxygen / Q000737:chemistry; D019810:Sodium Azide / Q000737:chemistry
chemical_list: D000081005:Cyclohexane Monoterpenes; D000081007:Cymenes; D039821:Monoterpenes; D010545:Peroxides; C075384:coniferaldehyde; C043372:ascaridole; D026082:Singlet Oxygen; C007210:4-cymene; D002084:Butylated Hydroxytoluene; D002083:Butylated Hydroxyanisole; D005054:Eugenol; C018669:gamma-terpinene; C036643:isoeugenol; D000171:Acrolein; D019810:Sodium Azide; D012256:Riboflavin; D000432:Methanol
keywords: Coniferylaldehyde; Dihydroeugenol; Eugenol; Isoeugenol; Photooxidation; Riboflavin; α-Terpinene