title: Biological and chemical stability of garlic-derived allicin.
abstract: This study verifies the instability of garlic ( Allium sativum L.)-derived allyl 2-propenylthiosulfinate (allicin) in various aqueous and ethanolic solutions as well as in vegetable oil through chemical and biological analyses performed simultaneously. Crushed fresh garlic cloves generated antibacterial activity and chemically detectable allicin, a major antibacterial principle, and both declined on a daily basis in aqueous and ethanolic solutions at room temperature, showing biological and chemical half-lives of about 6 and 11 days, respectively. Allicin was more stable in 20% alcohol than in water, but surprisingly unstable in vegetable oil, with an activity half-life 0.8 h, as estimated from its antibacterial activity toward Escherichia coli, and a chemical half-life of 3.1 h, based on chromatographic quantification. In alcoholic and aqueous extracts, the biological half-life of allicin tended to be longer than the chemical one, suggesting the occurrence of bioactive compounds other than allicin in the extracts.
authors.affiliation: Nihon University Graduate School of Applied Life Sciences, Fujisawa, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fujisawa
authors.forename: Kaoru
authors.initials: K
authors.lastname: Suma
authors.forename: Kana
authors.initials: K
authors.lastname: Origuchi
authors.forename: Hitomi
authors.initials: H
authors.lastname: Kumagai
authors.forename: Taiichiro
authors.initials: T
authors.lastname: Seki
authors.forename: Toyohiko
authors.initials: T
authors.lastname: Ariga
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000494:pharmacology; D004220:Disulfides; D004355:Drug Stability; D000431:Ethanol; D005737:Garlic / Q000737:chemistry*; D006207:Half-Life; D012996:Solutions; D013441:Sulfinic Acids / Q000032:analysis* / Q000494:pharmacology*; D014867:Water
chemical_list: D000900:Anti-Bacterial Agents; D004220:Disulfides; D012996:Solutions; D013441:Sulfinic Acids; D014867:Water; C006452:allicin; D000431:Ethanol