has role is protonated form of independent continuant quercetin A pentahydroxyflavone having the five hydroxy groups placed at the 3-, 3'-, 4'-, 5- and 7-positions. It is one of the most abundant flavonoids in edible vegetables, fruit and wine. CHEBI:16243 geroprotector antiviral agent antifibrotic agent pentahydroxyflavone antibacterial agent hypoglycemic agent cardiovascular drug antineoplastic agent chelator radical scavenger 7-hydroxyflavonol quercetin-7-olate ophthalmology drug anti-inflammatory agent Aurora kinase inhibitor hydroxyflavan anti-obesity agent anti-anaemic agent plant metabolite phytoestrogen EC 1.10.99.2 [ribosyldihydronicotinamide dehydrogenase (quinone)] inhibitor