RESUMO
The isolation and structure elucidation of two new flavonoids, chrysanthumones A and B from the extracts of Allium chrysanthum were reported. Seven known phenolic constituents were also isolated. Their structures were determined on the basis of NMR and MS techniques.
Assuntos
Allium/química , Flavonoides/isolamento & purificação , Flavonoides/química , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Casca de Planta/químicaRESUMO
Garlic (Allium sativum L.), which is a widely distributed plant, is globally used as both spice and food. This study identified five novel phenolic compounds, namely, 8-(3-methyl-(E)-1-butenyl)diosmetin, 8-(3-methyl-(E)-1-butenyl)chrysin, 6-(3-methyl-(E)-1-butenyl)chrysin, and Alliumones A and B, along with nine known compounds 6-14 from the ethanol extract of garlic. The structures of these five novel phenolic compounds were established via extensive 1D- and 2D-nuclear magnetic resonance spectroscopy experiments. The effects of the phenolic compounds isolated from garlic on the enzymatical or nonenzymatical formation of sulfur-containing compounds produced during garlic processing were examined. Compound 12 significantly reduced the thermal decomposition of alliin, whereas compound 4 exhibited the highest percentage of alliinase inhibition activity (36.6%).
Assuntos
Manipulação de Alimentos , Alho/química , Fenóis/farmacologia , Compostos de Enxofre/antagonistas & inibidores , Compostos Orgânicos Voláteis/antagonistas & inibidores , Liases de Carbono-Enxofre/antagonistas & inibidores , Cisteína/análogos & derivados , Cisteína/química , Temperatura Alta , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Fenóis/análise , Fenóis/química , Extratos Vegetais/química , Compostos de Enxofre/análise , Compostos Orgânicos Voláteis/químicaRESUMO
(R)-3-(allylthio)-2-((R)-3-(allylthio)-2-aminopropanamido)propanoic acid was isolated from the bulb of garlic, together with four known amino acids. Its structure was elucidated on the basis of 2D NMR and MS techniques. To the best of our knowledge, (R)-3-(allylthio)-2-((R)-3-(allylthio)-2-aminopropanamido)propanoic acid, which showed antibacterial activity against the Staphylococcus aureus antibiotic resistant strain, was the first example of dipeptide from garlic.