LINOLEIC-ACID OXIDATION IN THE PRESENCE OF AMINO-COMPOUNDS PRODUCES PYRROLES BY CARBONYL AMINE REACTIONS

The reactions of 13-hydroperoxy-9(Z),11(E)-octadecadienoic acid (13-LO OH) and its degradation product 4,5(E)-epoxy-2(E)-decenal with butylam ine and lysine were studied to determine whether pyrrole derivatives i solated in model reactions were produced in complex systems involving hydroperoxides. incubated reaction mixtures were studied by gas chroma tography coupled with mass spectrometry or high-performance liquid chr omatography coupled with mass spectrometry (HPLC-MS), and some compoun ds were isolated by column chromatography or semipreparative HPLC, and identified by H-1- and C-13-nuclear magnetic resonance spectroscopy a nd MS. The reaction of epoxyalkenals with amino groups produced two ty pes of pyrrole derivatives: 1-substituted 2-(1'hydroxyalkyl)pyr(r)oles and 1-substituted pyrroles. 1-Substituted 2-(1'-hydroxyalkyl)pyrroles were responsible for the development of color acid fluorescence by a polymerization reaction, which implied the formation of dipyrrylmethan es and dipyrrylmethenes. 1-Substituted pyrroles were final products in these reactions and their determination might be used as an index of oxidative stress. The above reactions were also observed between 13-LO OH and amino compounds, and suggested that the pyrrole polymerization mechanism plays a role in the fluorescence observed by reaction of hyd roperoxides and amino groups.