Flavonols from Pterogyne nitens and their evaluation as myeloperoxidase inhibitors

• Published in: Phytochemistry (Oxford) 2008-05, Vol.69 (8), p.1739-1744
• Main Authors: Regasini, Luis Octávio, Vellosa, José Carlos Rebuglio, Silva, Dulce Helena Siqueira, Furlan, Maysa, de Oliveira, Olga Maria Mascarenhas, Khalil, Najeh Maissar, Brunetti, Iguatemy Lourenço, Young, Maria Claudia Marx, Barreiro, Eliezer Jesus, Bolzani, Vanderlan Silva
• Format: Article
• Language: English
• Subjects: Acylated flavonol; Analytical, structural and metabolic biochemistry; Antioxidant; antioxidant activity; Biological and medical sciences; Chemical constitution; chemical structure; Drug Evaluation, Preclinical; enzyme inhibition; Enzyme Inhibitors - chemistry; Enzyme Inhibitors - isolation & purification; Enzyme Inhibitors - pharmacology; Enzymes and enzyme inhibitors; Fabaceae; Fabaceae - chemistry; flavonols; Flavonols - chemistry; Flavonols - isolation & purification; Flavonols - pharmacology; Fruit - chemistry; Fundamental and applied biological sciences. Psychology; Hydrolases; kaempferol; Magnetic Resonance Spectroscopy; Molecular Structure; Myeloperoxidase; oxidative stress; Peroxidase - antagonists & inhibitors; peroxidases; Plant physiology and development; Pterogyne; Pterogyne nitens; pterogynoside; spectral analysis
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2008.01.006

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. 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 0.50–50 nM, quercetin ( 5), isoquercitrin ( 6) and rutin ( 7) exhibited strong inhibitory effects with IC 50 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.