Synthesis and Antioxidant Activity of Quercetin Ethers.

Quercetin (Q) methyl ethers were synthesized from CHI under various conditions. The principal products from the reactions of Q with alkylhalides (CHI, CHBr) in DMF were 3,7,4′-tri-O-alkyl ethers. The structures of the products were confirmed by PMR and C NMR spectra. The antioxidant activity of Q tetra- and tri-O-methyl ethers was demonstrated by chemiluminescence in model systems generating active oxygen species and promoting lipid peroxidation. [ABSTRACT FROM AUTHOR]