title: Synthesis and antioxidant activity of nitrohydroxytyrosol and its acyl derivatives.
abstract: A series of nitroderivatives has been synthesized from hydroxytyrosol, the natural olive oil phenol, to increase the assortment of compounds with putative effects against Parkinson's disease. Nitrohydroxytyrosyl esters were obtained from nitrohydroxytyrosol using a chemoselective one-step, high-yield, transesterification procedure. The antioxidant activity of these new series of nitrocatechols was evaluated using FRAP, ABTS, and ORAC assays and compared to that of free hydroxytyrosol. The nitro functional group induced a significant increase in the antioxidant activity of nitrohydroxytyrosol compared to hydroxytyrosol. Regarding nitroester derivatives, variable antioxidant activity was observed depending on the acyl side-chain length; shorter chains maintained or even enhanced the antioxidant activity compared to nitrohydroxytyrosol, decreasing the activity with longer side chains in keeping with their lipophilic nature. Therefore, it may be concluded that nitroester derivatives of hydroxytyrosol, which may be obtained by a simple, high-yield reaction, have elevated antioxidant activity and thus present potential bioactivity.
authors.affiliation: Department of Organic and Pharmaceutical Chemistry, Faculty of Pharmacy, University of Seville , Seville, Spain.
authors.forename: Mariana
authors.initials: M
authors.lastname: Trujillo
authors.forename: Elena
authors.initials: E
authors.lastname: Gallardo
authors.forename: Andrés
authors.initials: A
authors.lastname: Madrona
authors.forename: Laura
authors.initials: L
authors.lastname: Bravo
authors.forename: Beatriz
authors.initials: B
authors.lastname: Sarriá
authors.forename: José A
authors.initials: JA
authors.lastname: González-Correa
authors.forename: Raquel
authors.initials: R
authors.lastname: Mateos
authors.forename: José Luis
authors.initials: JL
authors.lastname: Espartero
mesh_terms: D000975:Antioxidants / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D000975:Antioxidants; C005975:3,4-dihydroxyphenylethanol; D010626:Phenylethyl Alcohol
keywords: Parkinson’s disease; antioxidant activity; hydroxytyrosol; nitrocatechol; nitroester derivatives