Nicotine, nomicotine and

Tobacco and its alkaloids have long ceased to have any therapeutic importance, but their extensive use as insecticides and the demand for nicotine for the manufacture of nicotinic acid have stimulated interest in processes of extraction and methods of estimation. On the latter subject there is a voluminous literature, of which critical resumes have been published by various authors.Recent work on this subject has been specially concerned with (1) the development of miero- and semi-miero-methods suitable for estimating nieotine in tobacco smoke and the distribution of nieotine on sprayed garden produce, in treated soils and in tobaeeo leaves,(2) the study of conditions necessary to ensure satisfactory results in using particular processes, " and (3) methods of separation and estimation of nicotine, nomicotine and anabasine in mixtures of these bases. ) In the United States and in Russia considerable interest is being shown in the cultivation of types of tobacco rich in nicotine, in finding new industrial uses for tobacco and its alkaloids, and in possible by-products from tobacco plants such as citric and malic acids, i " Surveys of information on tobacco alkaloids have been published by Jackson, i Marion and Spath and Kuffner. ... 

The substituted pyridine derivatives are biologically active compounds. Nicotine, nomicotine and anabasine are natural insecticides known for a long time. Pyridine-2-thiol-l-oxide and pyridine-nitrile (2,6-dichloro-4-phenylpyridine-... 

Table 3. Acute toxicity of nicotine, nomicotine and anabasine in various species.

Cundiff, R.H and P.C. Markunas A rapid titrimetric procedure for the determination of nicotine, nomicotine, and total alkaloids in tobacco and tobacco products 7th Tobacco Chemists Research Conference, Program Booklet and Abstracts, Vol. 7, Paper No. 3, 1953, p. 4. 

In this way, generally after localisation through the fluorescence of the substances themselves, determinations have been carried out of coumarin derivatives, following chromatographic separation from lemon and grapefruit oils [729] quinoxaline derivatives of 2-ketoacids [651] benzo-(a)-pyrene [599] and vitamin Bg factors [702]. Cortisol [228] and aldosterone [229] which had been extracted from urine and purified by TLC, have been localised with the help of a reference chromatogram and then determined fluorometrically after treatment with sulphuric acid. After extraction from the thin layer, nicotine, nomicotine and anabasine could be determined phosphorimetrically (see p. 141) with a relative standard deviation of 6% [761]. 

Tobacco use is primarily due to psychopharmacological effects of nicotine (Henningfleld et al. 2006). Nicotine is a tobacco alkaloid, a basic substance that contains a cychc nitrogenous nucleus. In Nicotiana plants, most alkaloids are 3-pyridyl derivatives In cured leaf of Maryland Robinson Medium Broadleaf, 24 pyridine derivatives were identified, including nicotine, nomicotine, anabasine, oxynicotine, myosmine, 3-acetylpyridine, 2,3 -dipyridyl, iticotinamide, anatabine, nicotinic acid, and unidentified pyridine alkaloids of derivatives thereof (Tso 1990). Nicotine is the principal alkaloid in commercial tobacco (this was confirmed in 34 out of 65 Nicotiana species) nomicotine, rather than nicotine, appears to be the main alkaloid in 19 out of 65 species and anabasine is the third most important. In addition to the above-mentioned principal and minor alkaloids, the presence of many trace amounts of new alkaloids or their derivatives were frequently reported, including, for example, 2.4 -dipyridyl, 4,4 -dipyridyl, N -formylanabasine, A -formylanatabine, N -acetylanatabine, N -hexanoyl-nomicotine, N -octanoyl-nomicotine, T-(6-hydroxyoctanoyl) nomicotine, and l -(7-hydroxyoctanoyl) nor-nicotine. 

The predominant alkaloid fonnd in tobacco is (—)-nicotine other molecnles found in tissnes of smokers are either present in tobacco smoke or are metabolites of nicotine, inclnding (4-)-nicotine, (-P)-nomicotine, (—)-nomicotine and (—)-cotinine, the major metabolite (Clark et al. 1965). In animals trained to recognise the stunnlns produced by (—)-nicotine, (-P)-nicotine fully substituted for (—)-nicotine but was about one-tenth as potent. There was no stereoselectivity in responding observed with the metabolite nomicotine and both (-p) and (—)-isomers fully substituted for nicotine but again were 10-fold less potent. (—)-Cotinine also substitnted for nicotine at very high doses bnt this conld be explained by the presence of small amounts of (—)-nicotine in the sample of cotinine (Goldberg et al. 1989). 

Pyridine alkaloids are compounds with a pyridine nucleus and a pyrrohdine or piperidine unit. The pyrrohdine ring appears in nicotine and the piperidine ring in anahasine. Typical alkaloids from this group are nomicotine and anatahine. The a of pyridine alkaloids is nicotinic acid, the j8 is dihydronicohnic acid, the q> is 1,2-dihydropyridine (Figure 61). The A is nicotine and its P is nomicotine. ... 

The production of toxins is only one aspect of plant defense strategy. As a result of the persistent battle of plants and herbivores, many optimized phenotypes have evolved, such as the preferential accumulation of alkaloids in tissues with a pattern that is consistent with predictions of optimal defense theory,65 i.e., the defense metabolites are allocated preferentially to tissues with a high probability of attack.66 The inducibility of pathways leading to plant secondary compounds as a strategy to minimize the costs of plant defense is a result of permanent optimization. One of a few examples of inducible alkaloid biosynthesis is the different Nicotiana species that exhibit dramatic wound-induced increases of nicotine, nomicotine, or anabasine.67... 

Dewey, L.J. and W. Stepka A test of possible intermediates in the conversion of nicotine to nomicotine and some observations on the specificity of the reaction 17th Tobacco Chemists Research Conference, Program Booklet and Abstracts, Vol. 17, Paper No. 38, 1964, p. 25. 

Physiology biosynthesis Like the tropane alkaloids, T. a. are formed in the roots and transported to the aboveground parts for storage by the plant s phloem system. In some sorts of tobacco plants a part of the nicotine is demethylated to nomicotine during transport to the shoot. Nomicotine and anabasine are often the main alkaloids in the so-called nicotine-poor tobacco plant types. The T. a. are formed biogenetically from nicotinic acid, made available via the pyridine nucleotide cycle (see nicotinamide), and a pyrrolidine or piperidine building block (figure). In the case of nicotine, like for the tropane alkaloids, Al-methylpyr-roline is an intermediate, in the biosynthesis of anabasine the intermediate is a piperidine derived from the amino acid lysine (see piperidine alkaloids). 

I. 2,3 -PyridylpyrroIidines and their dalvatives, e.g., nicotine, nomicotine, myosmine, nicotyrine, cotinine, A -acylnomicotines, nicotine-A -oxides... 

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