... the glycoside form of quercetin, is a bioflavonol having aromatic trimeric heterocyclic structure. It is a naturally occurring pigment. It, chemically 3 ... ) -5,7-dihydroxy-4H-1-Benzopyran-4-one, is a yellow to greenish crystalline powder melting at 190 C. Rutin is ... hesperetin, hesperidin, nobiletin, quercetin, sinensetin, and tangeretin. It is not a dietary essential but is known to have the effect on ...