RT Journal Article SR Electronic T1 N-Methylnornicotinium ion, a new in vivo metabolite of R-(+)-nicotine. JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 348 OP 353 VO 13 IS 3 A1 M Sato A1 P A Crooks YR 1985 UL http://dmd.aspetjournals.org/content/13/3/348.abstract AB N-Methylnornicotinium ion has been identified as a metabolite in the urine of male Hartley guinea pigs that had been chronically dosed ip with R-(+)-nicotine. Under similar conditions, S-(-)-nicotine is not biotransformed into this metabolite. The metabolite was isolated and purified by preparative high performance cation-exchange liquid chromatography. The structural identity of the metabolite was determined by UV spectrophotometric analysis and sodium borohydride reduction followed by GLC-mass spectrometric analysis, and Fourier transform 1H NMR spectrometric analysis. The formation of this metabolic product from nicotine represents a unique example of N-demethylation and N-methylation reactions both occurring within the same molecule.