Electrochemical and enzyme-catalyzed oxidation chemistry of indole-3-acetic acid.

摘要

The electrochemical and peroxidase-catalyzed oxidations of indole-3-acetic acid (IAA) in aqueous solution at pH 2.2 and pH 7.4 have been studied. IAA is a well known plant growth hormone. The biological activity of IAA is considered to be the result of enzyme oxidatiom of IAA in plants, which forms active products. IAA has also been detected in human urine, plasma, cerebrospinal fluid and brain. Increased concentration of IAA in human urine has been reported in several neurological disorders.;The principal purpose of this project was to perform detailed studies of the redox chemistry of IAA in order to provide fundamental information which might have a bearing on the biological oxidation of IAA. Oxidation reaction mixtures were separated by high performance liquid chromatography. More than fifteen oxidation products were structurally characterized using UV-visible, mass spectrometry, nuclear magnetic resonance spectroscopy and electrochemical methods. Reaction mechanisms for formation of these products have been proposed. The first voltammetric oxidation peak of IAA corresponds to an initial 2e, 1H