Studies on the pyrrolinone metabolites derived from the tobacco alkaloid 1-methyl-2-(3-pyridinyl)pyrrole (beta-nicotyrine)

Previous studies have established that the tobacco alkaloid 1-methyl-2-(3-p yridyl)pyrrole (beta-nicotyrine) is biotransformed by rabbit lung and liver microsomal preparations to an equilibrium mixture of the corresponding 3- and 4-pyrrolin-2-ones. Autoxidation of these pyrrolin-2-ones generates the chemically stable 5-hydroxy-5-(3-pyridinyl)-3-pyrrolin-2-one. This paper su mmarizes efforts to document more completely the pathway leading to this hy droxy-pyrrolinone. Chemical and spectroscopic evidence implicates the 2-hyd roxy-1-methyl-5-(3-pyridinyl)pyrrole (2-hydroxy-beta-nicotyrine) as the key intermediate in this reaction pathway. Of potential toxicological interest is the detection of radical species derived from the autoxidation of this compound.