Flavonoids are antioxidant compounds found in plants. Animals do not produce flavonoids and so they get them from diet. Flavonoids not only protect plants, they also protect animals - and therefore humans. Diets high in fruits and vegetables provide protection against cardiovascular disease, cancer and other diseases. Flavonoids are diverse both in their characteristics and chemical structures. Over four thousand of them have been identified and it is said that there could be as many as twenty thousand in plants. The general structure of flavonoids is generally based on C6-C3-C6 or diphenylpropane skeleton.