ELECTROCATALYTIC HYDROGENATION REACTION OF NARINGINCHALCONE

M.A. NAZARENO ; A.M.GIANNUZZO; H. MISHIMA; B. LÓPEZ DE MISHIMA

Varsovia

Congreso; 51st Annual Meeting International Society Electrochemistry; 2000

International Society Electrochemistry

The electrocatalytic hydrogenation reaction of naringin derivated chalcone is studied. Thereaction is carried out with different catalysts for comparing with the classic catalytic hydrogenation. Naringin, a flavonoid extracted from the peel of some citric fruits and the responsible of their bitterness, is the precursor of the dihydrochalcone compound. This kind of substances derived from flavonoids presents a very intense sweet taste1 therefore their synthesis become interesting because of their industrial potential as a sweetener.For studying the reaction that produces the dihydrochalcone the experiences were carried out inalkaline media where the equilibrium between the flavanone and the chalcone is shifted to thechalcone form. The position of this equilibrium was evaluated by UV-Vis absorption spectroscopy.For initial studies of chalcone oxidation-reduction behavior a platinum pure electrode was used.The results show that there is no evidence of chalcone reaction in the potential region of bothhydrogen and oxygen evolutions. On the other hand, the adsorption of organic molecule on platinum also was studied. The chalcone was adsorbed in the hydrogen electroadsorption potential zone. The electrocatalytic hydrogenation reactions were performed at constant potential with PtO2 and palladium-gold electrodes .and the reaction products were analysed by UV-Vis spectroscopy, HPLC and TLC. Also the classic hydrogenation reaction was done using PtO2 as catalyst for comparing purposes of the yields. In both cases the dihydrochalcone was obtained.References[1] R.M. Horowitz, B. Gentili, U.S. Patent 3.087.821, 1963. 3.890.296, 1975. 3.890.298, 1975