title: Protective effects of flavonoids and extract from Vellozia kolbekii Alves against oxidative stress induced by hydrogen peroxide in yeast.
abstract: Two flavonoids 3,5,7,3',4'-pentahydroxy-6-prenylflavonol (1) and 3,5,7,3',4'-pentahydroxy-8-methyl-6-prenylflavonol (2) were isolated from the ethyl acetate extract of sheaths of Vellozia kolbekii Alves (Velloziaceae). This is the first time that compound 2 has been described. The crude extract and flavonoids were found to be active as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavengers and were able to the increase tolerance of the eukaryotic microorganism Saccharomyces cerevisiae to oxidative stress generated by H(2)O(2). The protective effect was correlated with a reduction in the oxidation of proteins and lipids. In addition, flavonoids isolated from Velloziaceae showed an inhibitory effect on mutations in p53, which is mutated and nonfunctional in more than 50% of cases of human cancer.
authors.affiliation: Laboratory of the Analysis of Aromas, Department of Organic Chemistry, Institute of Chemistry, Federal University of Rio de Janeiro, Athos da Silveira Ramos, 149, University City, 21945-970 Rio de Janeiro, RJ, Brazil. carme_gomes@yahoo.com.br
authors.forename: Carmelita Gomes
authors.initials: CG
authors.lastname: da Silva
authors.forename: Camilla Dayane F
authors.initials: CD
authors.lastname: Carvalho
authors.forename: Lidilhone
authors.initials: L
authors.lastname: Hamerski
authors.forename: Frederico A V
authors.initials: FA
authors.lastname: Castro
authors.forename: Ruy José Válka
authors.initials: RJ
authors.lastname: Alves
authors.forename: Carlos Roland
authors.initials: CR
authors.lastname: Kaiser
authors.forename: Elis Cristina Araújo
authors.initials: EC
authors.lastname: Eleutherio
authors.forename: Cláudia Moraes
authors.initials: CM
authors.lastname: de Rezende
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity*; D015227:Lipid Peroxidation / Q000187:drug effects; D019684:Magnoliopsida / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D050050:Protein Carbonylation / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010936:Plant Extracts; D006861:Hydrogen Peroxide