**1.15. Flavonoids**

Flavonoids belong to a group of important polyphenols which are widely distributed among plants. They have more than one benzene ring in its structure and are used as antioxidants or free radical scavengers [27]. Flavans are parent compounds from which they are derived. Out of over 4,000 flavonoids that exist, some are found as pigments in higher plants. About 70% of plants contain common flavonoids such as quercetin, kaempferol, and quercitrin. Among other groups of flavonoids in existence are flavones, flavans, anthocyanidins, dihydroflavons, flavonols, chalcones, and catechin [27]. Flavonoids function to reduce the risk of coronary heart diseases [41] and possess anticoagulant, anti-inflammatory, and aphrodisiac properties [42].
