SYNTHESIS AND ANALYSIS OF OXIDATION AND CARBONYL CONDENSATION COMPOUNDS OF TRYPTOPHAN

Modified methods of synthesizing the oxidative degradation products N-formylkynurenine, oxyindolylalanine diastereomers and dioxyindolylalanine diastereomers (DiOia) and the carbonyl condensation products 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid and 1-pentyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid are described. These methods produce compounds with purities sufficiently high to allow them to be used as reference substances for analytical purposes and as samples for toxicological investigations. The obtained substances were characterized by H-1-NMR,C-13-NMR, IR and UV spectroscopy. The purities of the substances were verified by RP-HPLC and UV detection. An RP-HPLC method was developed which allowed the separation of the synthesized products, 5-hydroxytryptophan, 3-hydroxykynurenine and tryptophan. As an application, a sample of eosinophilia-myalgia syndrome (EMS)-related tryptophan was examined. Low contents of the oxidation products were found, together with the known peaks A-E.