Abstract
Kaempferol (3,4′,5,7-tetrahydroxyflavone) was oxidized by O2 to 4-hydroxyphenylglyoxylic acid and phloroglucinolcarboxylic acid as identified by UV spectroscopy and high-performance liquid chromatography. The molar yields of the two compounds on the basis of kaempferol oxidation were 19% and 21%, respectively, at pH 8. In addition to these two products, a compound which was hydrolyzed to 4-hydroxybenzoic acid and an unidentified compound was produced.