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Catechins and quercetin are major polyphenols in many plant foods that have been related to health promotion. In the human organism they are largely metabolized to different metabolites, which are further found in plasma and should contribute to the biological effects associated to the intake of the parent compounds. An important step in quercetin and catechins metabolism is the O-methylation of the catechol group, which can be expected to have an effect on their antioxidant and scavenging properties. In the present work, the 3′- and 4′-methylethers of catechin and epicatechin have been prepared and characterised and their antioxidant activity evaluated and compared to that of the corresponding quercetin derivatives. The antioxidant activity was assessed using the ferric reducing power (FRAP) assay and two methods based on the ability to scavenge the ABTS⁺ radical cation at different pH values. In these …