[Polarographic study of quinones formed during oxidation of caffeic and chlorogenic acids].
Polarographic behaviour of a number of substituted ortho-benzenquinones was studied in weakly acidic, neutral and weakly caustic solutions (up to pH --9.0). Half-wave potential depends on the solution pH, indicating protonization of the carbonyl groups of the quinones. Protonization is probably stipulated by the hydroxonium ions. Protonization may take place not only under the action of water, but also under the effect of other acidic components, as indicated by the dependence of E1/2 on the undissociated acetic acid centrifugation. The condensation and polymerization reactions are characteristic for the ortho-quinones. A shift of the quinone potential indicates dimerization of the electrode products.
D002109:Caffeic Acids; D002726:Chlorogenic Acid; D010084:Oxidation-Reduction; D011048:Polarography; D011809:Quinones
D002109:Caffeic Acids; D011809:Quinones; D002726:Chlorogenic Acid
Poliarograficheskoe izuchenie khinonov, obrazuiushchikhsia pri okislenii kofeĭnoi ĭ khlorogenovoĭ kislot