Myosmine is a minor tobacco alkaloid that is structurally related to nicotine [1][3][4].
Myosmine is a specific tobacco alkaloid. It is found in a variety of other plants such as maize, rice, wheat flour, millet, potato, and milk and also cocoa, popcorn, tomato, carrot, pineapple, kiwi, and apples. Myosmine is easily nitrosated, yielding 4-hy-droxy-1-(3-pyridyl)-1-butanone (HPB) and a DNA adduct identical to the esophageal tobacco carcinogen N-nitrosonornicotine [2][4].
Myosmine is a minor tobacco alkaloid that is structurally related to nicotine. Nicotine is the addictive active ingredient in tobacco smoke that acts as an agonist at neuronal nicotinic acetylcholine receptors with Ki values of 480.69 and 11.13 nM for α3β4 and α4β2 subtypes, respectively [2]. Myosmine weakly binds to a4β2 nACh receptors with Ki value of 3.3 μM [3].
In rats treated with combinations of myosmine and NaNO2, no evidence showed the production of HPB-releasing Hb and DNA adducts, suggesting that exposure to dietary myosmine couldn’t lead to HPB-releasing DNA or Hb adducts in humans [5].
References:
[1]. Tyroller S, Zwickenpflug W, Richter E. New sources of dietary myosmine uptake from cereals, fruits, vegetables, and milk. J Agric Food Chem. 2002 Aug 14;50(17):4909-15.
[2]. Zaveri N, Jiang F, Olsen C, et al. Novel α3β4 nicotinic acetylcholine receptor-selective ligands. Discovery, structure-activity studies, and pharmacological evaluation. J Med Chem. 2010 Nov 25;53(22):8187-91.
[3]. Ferretti G1, Dukat M, Giannella M, et al. Binding of nicotine and homoazanicotine analogues at neuronal nicotinic acetylcholinergic (nACh) receptors. Bioorg Med Chem Lett. 2003 Feb 24;13(4):733-5.
[4]. Zwickenpflug W, Tyroller S, Richter E. Metabolism of myosmine in Wistar rats. Drug Metab Dispos. 2005 Nov;33(11):1648-56.
[5]. Hecht SS, Han S, Kenney PM, et al. Investigation of the reaction of myosmine with sodium nitrite in vitro and in rats. Chem Res Toxicol. 2007 Mar;20(3):543-9.