The objective of this work was to verify the antioxidant effect of the flavonoid compounds quercetin, naringenin, morin, and rutin isolated from soybean, cultivar UFV-5. After acetylation with acetic anydride and pyridine, and methylation with diazomethane, indexes of acidity, iodine, and peroxide and Kreiss reaction were determined. The best results were obtained with methylated naringenin, acetylated naringenin, methylated quercetin, and acetylated quercetin.
