title: Antioxidant properties of gingerol related compounds from ginger.
abstract: Ginger (Zingiber officinale Roscoe) shows an antioxidant activity, and we have been engaging to determine the structures of more than 50 antioxidants isolated from the rhizomes of ginger. The isolated antioxidants are divided into two groups; gingerol related compounds and diarylheptanoids. In this study, structure-activity relationship of gingerol related compounds was evaluated. Gingerol related compounds substituted with an alkyl group bearing 10-, 12- or 14-carbon chain length were isolated from the dichloromethane extract of rhizomes using repeated chromatographic techniques. The antioxidant activities of these compounds were evaluated by the following measurements; 1) 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2) inhibitory effect on oxidation of methyl linoleate under aeration and heating by the Oil Stability Index (OSI) method, and 3) inhibitory effect on oxidation of liposome induced by 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH). These results suggested that the substituents on the alkyl chain might contribute to both radical scavenging effect and inhibitory effect of autoxidation of oils, while inhibitory effects against the AAPH-induced peroxidation of liposome was somewhat influenced by the alkyl chain length; the antioxidant activity might be due to not only radical scavenging activity of antioxidants but also their affinity of the antioxidants to the substrates.
authors.affiliation: Division of Food and Health Sciences, Graduate School of Human Life Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Masuda
authors.forename: Hiroe
authors.initials: H
authors.lastname: Kikuzaki
authors.forename: Masashi
authors.initials: M
authors.lastname: Hisamoto
authors.forename: Nobuji
authors.initials: N
authors.lastname: Nakatani
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D002396:Catechols; D005233:Fatty Alcohols / Q000302:isolation & purification / Q000494:pharmacology*; D020939:Zingiber officinale / Q000737:chemistry; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D013329:Structure-Activity Relationship; D024502:alpha-Tocopherol / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D002396:Catechols; D005233:Fatty Alcohols; D010936:Plant Extracts; C007845:gingerol; D024502:alpha-Tocopherol; D001205:Ascorbic Acid