What is Quercetin? Quercetin is a plant polyphenol from group of flavonoids, specifically is a flavonol. Its name has been used since 1857, and is derived from quercetum (oak forest). It has a bitter flavor and it's used for supplement, beveraged or foods. Properties Quercetin it is well known for its antioxidant activity due to its ability to scavenge free radicals. It consider to be the most potent scavenger of ROS. These properties make quercetin a good lipid peroxidation inhibitor, this type of peroxidation can create deleterious effects throughout the body, such as cardiovascular and neurodegenerative diseases. In addition, quercetin does not only stop the propagation of lipid peroxidation, but also increases glutathione levels. By scavenging free radicals quercetin can also reduce inflammation, and protect cells suffering oxidative stress. What is so special about it? According to Structure-Activity Relationship (SAR) three structural features are essent