Nornicotine

Nornicotine is a minor tobacco alkaloid and a primary metabolite of nicotine, formed via cytochrome P450-mediated N-demethylation (PubChem CID 10468). It is not a therapeutic target itself but acts as a potent agonist at nicotinic acetylcholine receptors (nAChRs), particularly the alpha-7 and alpha-4-beta-2 subtypes (PMID: 11432013). While it possesses a lower affinity for most nAChRs compared to nicotine, its significantly longer biological half-life allows it to accumulate and potentially mediate long-term effects of tobacco use (PMID: 15601434). Nornicotine is of significant clinical interest due to its role in tobacco addiction and its potential to be nitrosated into N-nitrosonornicotine (NNN), a potent Group 1 carcinogen (PMID: 9715444). Consequently, it is often used as a biomarker for tobacco exposure and nicotine metabolism (PMID: 15601434). Its pharmacological profile is studied to understand the complex neurobiology of nicotine dependence and potential cognitive effects (PMID: 12606501). In the brain, it stimulates the release of dopamine in the mesolimbic pathway, contributing to the reinforcing properties of tobacco (PMID: 11432013). Despite its activity, it is not currently used as a therapeutic agent due to its toxicity and association with cancer risk.

Other names

3-(pyrrolidin-2-yl)pyridine2-(3-pyridyl)pyrrolidineDesmethylnicotine(S)-3-(pyrrolidin-2-yl)pyridine

Nornicotine acts as an agonist at nicotinic acetylcholine receptors (nAChRs), particularly the alpha-7 and alpha-4-beta-2 subtypes, which modulates the release of neurotransmitters like dopamine (PMID: 11432013).