ABSTRACT
Flavones comprise a large group of common plant metabolites. It appears that they are secondary metabolites involved in the plant growth hormone and growth regulators in defense against infection. Flavone sulfates and in particular alkaloid flavones are uncommon in plants. Some flavonoids are mutagenic in bacterial test systems, but are not mutagenic in vivo. They possess the capacity to inhibit chemical carcinogenesis in experimental animals. The chapter describes Isolation, purification, and preliminary identification of flavones using paper chromatography, column chromatography, and thin layer chromatography. Flavones occur practically in all parts of plants, most frequently in glycosidic combination. In bud exudates and on leaf and fruit surfaces they occur in the free state (aglycone) and/or in O-methylated form. Mammalian toxicity of flavones is very low as demonstrated by pharmacological studies. They are subjected to hydrolysis by intestinal microorganisms and will only be absorbed to a limited extent as intact flavones and flavonols.
