(1'S,2'S)-nicotine-1'-N-oxide is a stereoisomer of nicotine-1'-N-oxide, an oxidation product of S-(-)-nicotine. N-1'-oxidation of nicotine is mediated via flavin-containing monooxygenase. A marked stereoselectivity has been observed in the formation of N-1'-oxide metabolites from nicotine. Mammal hepatic preparations generally produce more the N-1'R,2'S-cis diastereoisomer than N-1'S,2'S-trans diastereoisomer after incubation with S-(-)-nicotine. (1'S,2'S)-nicotine-1'-N-oxide was reported to bind alpha3beta4 neuronal nicotinic acetylcholine receptor. cis- and trans-nicotine-N'-oxides modulate the development of tumors in rats initiated with N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide.

N‑Nitrosonornicotine (NNN) is a nitrosamine compound. It is produced by nitrosation of nicotine during the curing, aging, processing, and smoking of tobacco. About half of the NNN originates in the unburnt tobacco, whereas the remainder is formed during burning. NNN is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals. NNN induces deleterious mutations in oncogenes and tumor suppression genes by forming DNA adducts, which could be considered as tumor initiation. Meanwhile, the binding of NNN to the nicotinic acetylcholine receptor promotes tumor growth by enhancing and deregulating cell proliferation, survival, migration, and invasion, thereby creating a microenvironment for tumor growth.

1-methyl-4-(3-pyridinyl) pyrrole (β-nicotyrine) is a tobacco alkaloid. It is a potent inhibitor of cytochrome P450 CYP2A13 and a mechanism-based inactivator of cytochrome P450 CYP2A6.

Myosmine (3-(1-pyrrolin-2-yl)pyridine) is a minor tobacco alkaloid widely occurring in food products of plant and animal origin. Myosmine expresses significant genotoxic effects in human target cells of carcinogenesis. After nitrosation and/or peroxidation, myosmine gives rise to reactive pyridyloxobutylating species which are capable of forming pyridyloxobutylated DNA adducts.

Cotinine is a product formed after the chemical nicotine enters the body. Measuring cotinine in people’s blood is the most reliable way to determine exposure to nicotine for both smokers and nonsmokers exposed to environmental tobacco smoke. Cotinine is safe, non-addictive and has pharmacokinetic properties adequate for therapeutic use. Research has shown that cotinine has antipsychotic, anxiolytic, and antidepressant properties and modulates the serotonergic, cholinergic and dopaminergic systems. Cotinine behaves as a positive allosteric modulator of the nicotinic acetylcholine receptors and has anti-inflammatory effects. Cotinine is under investigation as an agent for the treatment of depression, PTSD, schizophrenia, Alzheimer's disease and Parkinson's disease.