BEHAVIOR OF CATECHIN AND ELLAGIC ACID SUBJECTED TO THERMALLY-ASSISTED HYDROLYSIS METHYLATION GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

Catechin and ellagic acid, two basic constituents of important natural polyphenols such as condensed tannins and ellagitannins, were subjected to thermally-assisted hydrolysis-methylation in the presence of tetramethylammonium hydroxide (25% aq.). The reaction was carried out at 600 degrees C for 5s using a platinum filament pyrolyzer which, in turn, was connected to a gas chromatograph/ion trap detector mass spectrometer. The permethylated compounds determined in the pool of the reaction products suggest that the reaction occurring is different from a simple methylation of free hydroxyls after thermal degradation and entails thermal fission of different bonds than those involved in conventional pyrolysis or chemical hydrolysis as the main decomposition pathway. The mass spectra of the permethylated hydrolysis products of catechin and ellagic acid are of practical use in the analysis of plant materials containing condensed tannins and ellagitannins.