title: Flavonols from Pterogyne nitens and their evaluation as myeloperoxidase inhibitors.
abstract: A myeloperoxidase inhibitory kaempferol derivative, namely pterogynoside (1), was isolated from fruits of Pterogyne nitens, along with six known flavonols, kaempferol, afzelin, kaempferitrin, quercetin, isoquercetrin and rutin. The structures of all compounds were elucidated primarily from 1D and 2D NMR spectroscopic analyses, as well as by high resolution mass spectrometry. All flavonols were screened to identify secondary metabolites as potential myeloperoxidase (MPO) inhibitors, and at concentrations of 0.50-50nM, quercetin (5), isoquercitrin (6) and rutin (7) exhibited strong inhibitory effects with IC50 values of 1.22+/-0.01, 3.75+/-0.02 and 3.60+/-0.02, respectively. The MPO activity detected for the new derivative 1 was markedly decreased (IC(50) 10.3+/-0.03) when compared with known flavonols 5-7, and interestingly increased when tested against ABTS scavenging activity.
authors.affiliation: Universidade Estadual Paulista, Instituto de Química, NuBBE - Núcleo de Bioensaios, Biossíntese e Ecofisiologia de Produtos Naturais, Araraquara, SP, CP 355, CEP 14801-970, Brazil.
authors.forename: Luis Octávio
authors.initials: LO
authors.lastname: Regasini
authors.forename: José Carlos Rebuglio
authors.initials: JC
authors.lastname: Vellosa
authors.forename: Dulce Helena Siqueira
authors.initials: DH
authors.lastname: Silva
authors.forename: Maysa
authors.initials: M
authors.lastname: Furlan
authors.forename: Olga Maria Mascarenhas
authors.initials: OM
authors.lastname: de Oliveira
authors.forename: Najeh Maissar
authors.initials: NM
authors.lastname: Khalil
authors.forename: Iguatemy Lourenço
authors.initials: IL
authors.lastname: Brunetti
authors.forename: Maria Claudia Marx
authors.initials: MC
authors.lastname: Young
authors.forename: Eliezer Jesus
authors.initials: EJ
authors.lastname: Barreiro
authors.forename: Vanderlan Silva
authors.initials: VS
authors.lastname: Bolzani
mesh_terms: D004353:Drug Evaluation, Preclinical; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D007887:Fabaceae / Q000737:chemistry*; D044948:Flavonols / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D005638:Fruit / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009195:Peroxidase / Q000037:antagonists & inhibitors*
chemical_list: D004791:Enzyme Inhibitors; D044948:Flavonols; C531205:pterogynoside; D009195:Peroxidase