title: HPLC isolation of antioxidant constituents from Xanthoparmelia spp.
abstract: A chromatographic method is described for the purification and characterization of secondary lichen substances with biological activity. A simple reversed-phase high-performance liquid chromatography method with gradient elution has been developed that allows the determination and isolation of salazinic, usnic and stictic acids from lichen samples in a single run and the quantification of every acid in the tested extracts. The antioxidant activity of both the isolated compounds and the respective lichen belonging to Xanthoparmelia genus was determined by the Oxygen Radical Absorbance Capacity (ORAC) assay; their effect as free radical scavengers, effect on cell survival by the 3(4,5-dimethyltiazol-2-yl)-2,5-diphenyltetrazolium reduction assay and 2',7'-dichlorofluorescin diacetate method were tested on U373 MG human astrocytome cell line. Both lichens extracts and all isolated compounds protected U373 MG cells from hydrogen peroxide-induced damage, suggesting that they could act as antioxidant agents in those neurodegenerative disorders associated with oxidative damage, such as Alzheimer's disease and Parkinson's disease.
authors.affiliation: Vegetal Biology II Department, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain.
authors.forename: G Amo
authors.initials: GA
authors.lastname: de Paz
authors.forename: J
authors.initials: J
authors.lastname: Raggio
authors.forename: M P
authors.initials: MP
authors.lastname: Gómez-Serranillos
authors.forename: O M
authors.initials: OM
authors.lastname: Palomino
authors.forename: E
authors.initials: E
authors.lastname: González-Burgos
authors.forename: M E
authors.initials: ME
authors.lastname: Carretero
authors.forename: A
authors.initials: A
authors.lastname: Crespo
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification* / Q000494:pharmacology; D001572:Benzofurans / Q000032:analysis; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D056148:Chromatography, Reverse-Phase / Q000295:instrumentation* / Q000379:methods*; D004354:Drug Screening Assays, Antitumor / Q000379:methods; D016166:Free Radical Scavengers / Q000494:pharmacology; D006576:Heterocyclic Compounds, 4 or More Rings / Q000032:analysis; D006801:Humans; D007783:Lactones / Q000032:analysis; D008011:Lichens / Q000737:chemistry*; D010082:Oxepins / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D012459:Salicylates / Q000032:analysis
chemical_list: D000975:Antioxidants; D001572:Benzofurans; D016166:Free Radical Scavengers; D006576:Heterocyclic Compounds, 4 or More Rings; D007783:Lactones; D010082:Oxepins; D010936:Plant Extracts; D012459:Salicylates; C116675:salazinic acid; C522101:stictic acid; C073339:usnic acid