ABSTRACT
Malondialdehyde (MDA) is one of several decomposition products of lipid peroxides formed in fats and oils, in food, and in the tissues. It is the most extensively investigated of these products because of its reactivity with a range of biological macromolecules and its association with the pathophysiology of a number of disease states. MDA is formed enzymatically as a product of the cyclooxygenase reaction in prostaglandin and thromboxane synthesis. There is undoubtedly some free MDA in foods, as indicated by its collection as a volatile product of cooking, but the amount present is difficult to determine because of its artifactual formation. MDA derivatives excreted in the urine are of interest as possible indicators of the forms of MDA in the diet and of the nature of its reactions in vivo. An MDA-cross-linked glycine-adenine adduct was obtained by reacting the enaminal of 9-ethyladenine with glycine methyl ester, indicating that MDA-mediated amino acid-nucleic acid cross-links may occur in vivo.
