Quercetin, a common bioflavonol composed of two benzene rings linked with a heterocyclicpyrone ring (aromatic trimeric heterocyclic), is a water-soluble pigment synthesized or naturally occurring in the rind and bark of numerous plants. It, chemically 2-(3,4-dihydroxyphenyl)-3,5,7- trihydroxy- 4H-1-benzopyran-4-one, is a yellow to greenish crystalline powder melting at 302 C. Bioflavonoids are called phytochemicals, Vitamin P, and Vitamin C2. There are about 2000 known bioflavonoids including  catechin, citrin, eriodictin, hesperetin, hesperidin, nobiletin, quercetin, rutin, sinensetin, and tangeretin. Vitamin P is not a dietary essential but is known to have the effect on capillary disorders.  It increases the strength of the walls of the blood capillaries and regulates their permeability. It may have an contribution to the total antioxidant activity and detoxifiers. It may enhance the action of Vitamin C. It is  considered that it lowers down cholesterol levels if it taken with Vitamin C. It is also know to have pharmacological action as an anti-inflammatory ,antihistaminic and antiviral agent.