Spectroscopic studies of methylglyoxal in water and dimethylsulfoxide.

Methylglyoxal is a highly reactive dicarbonyl compound, which reacts in vivo with biological macromolecules and thereby affects their structure and function. These changes are associated with complications during aging, diabetes and Alzheimer's disease as well as with growth inhibition in different tumors. Many enzymes are involved in the metabolism of methylglyoxal, but its true physiological role in metabolism and chemical properties are still obscure. In this study it was shown that methylglyoxal, during the freeze-drying of aqueous solutions, polymerizes into small polymeric structures which are stable in organic media such as dimethylsulfoxide. When re-exposed to water, the polymers are immediately transformed into the monomeric mono- and dihydrate forms of methylglyoxal. By NMR and UV spectroscopy, it was shown that solvent, temperature, and the amount of available water strongly influence the equilibrium of the different forms of methylglyoxal and thereby change its reactivity. 1H and 13C NMR spectroscopy were used to determine the structures of the different monomeric and oligomeric structures of methylglyoxal.