<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A member of a group of substances found in many plants and plant-based foods. Flavonoids have shown antioxidant effects.</n0:def-definition><n0:def-source>NCI-GLOSS</n0:def-source></n0:ComplexDefinition><n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A class of polyphenols which are biogenetically derived from a phenylpropane (C6-C3 unit) and three C2 units to form a benzopyran with an additional phenyl group at C-2 (C6-C3-C6 unit). They consist of 15 carbons and vary by oxidation/hydroxylation, glycosidation, and other functional groups. Historically, the benzene ring is denoted 'A'-ring, the pyran ring 'C' ring, and the phenyl ring 'B'-ring. The numbering of the phenyl ring starts with 1' (""one prime"") at the carbon that is connected to the pyran ring, and follows along the phenyl ring with C-2', -3', -4', -5', and -6'.</n0:def-definition><n0:def-source>CRCH</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>One of a number of chemical compounds found in certain fruits, vegetables and seeds with antioxidant properties and potential antineoplastic properties. As polyphenolic, soluble plant pigments, flavonoids are usually subdivided into 5 subgroups flavonols, flavones, flavonones, flavan-3-ols, anthocyanidins. Although not considered essential nutrients, some flavonoids may be beneficial to health by strengthening and protecting blood vessels and connective tissue and acting as anti-inflammatory, antihistaminic, and antiviral agents. As antioxidants, some flavonoids may protect lipids from oxidative damage or retard the formation of cataracts. (NCI04)</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>