Pyrrole formation from 4-hydroxynonenal and primary amines.

The reaction of trans-4-hydrory-2-nonenal (4-HNE) with primary amines was investigated to elucidate chemistry that may clarify the nature of its physiological covalent binding with protein-based primary amino groups. Such binding of 4-HNE, generated endogenously from lipid peroridation, appears to be a pathophysiologic factor in the modification of low-density lipoprotein and perhaps other instances. We now show that 4-HNE reacts with primary amines in aqueous acetonitrile at pH 7.8 to afford after workup, in 14-23% yield, the corresponding pyrroles, which were characterized by independent synthesis from 4-orononanal