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Nicotine constitution

Precursors and Formation. Tobaccos used for commercial products in the U.S.A, contain between 0,5 and 2,7% alkaloids. Nicotine constitutes 85-95% of the total alkaloids (14,26,27). Important minor alkaloids are nornicotine, anatabine, anabasine, cotinine and N -formylnornicotine (Figure 6), Several of these alkaloids are secondary and tertiary amines and, as such, amenable to N-nitrosation. The N-nitrosated alkaloids identified to date in tobacco and tobacco smoke include N -nitrosonornico-tine (NNN), 4-(methylnitrosamino)-l-(3-pyridyl)-l-butanone (NNK) and N -nitrosoanatabine (NAT Figure 7). In model experiments, nitrosation of nicotine also yielded 4-(methylnitrosamino)-4-(3-pyridyl)butanal (NNA 28). [Pg.258]

Alkaloids constitute approximately 2-4% by weight of fresh cigarette tobaccos (Kuhn 1965), with nicotine constituting roughly 95% of the total alkaloid fraction. The predominant secondary alkaloids, along with approximate percentages by weight of the alkaloid fraction, include anatabine (2-3%), nornicotine (1%), anabasine (0.5%), and myosmine (0.1%) (Kuhn 1965 Leete 1983). [Pg.164]

The nasal spray is available only by prescription. One spray to each nostril constitutes a dose. Although one dose delivers approximately 1 mg of nicotine. [Pg.319]

In a study for precursor determination, we stem-fed individual Burley leaves with nicotine-2 - C or nornicotine-2 - C (29). Subsequently, the leaves were air cured, dried and analyzed for NNN and NNN- C. Recovery of the p-activity in the form of NNN- C amounted to 0.009% and 0.007%, respectively of the stem-fed label. This demonstrates that both alkaloids give rise to NNN. More importantly, it points to the fact that the tertiary amine, nicotine, which constitutes 0.5-2.6% of commercial tobaccos (26,27), is the major precursor for the carcinogenic tobacco-specific NNN, while the secondary amine, nornicotine is of lesser importance because it amounts to only 0.005-0.06% in tobacco (Figure 8). [Pg.258]

Pictet, A. 8c Crepieux, P. (1895) Ueber phenyl- und pyridylpyrrole und che constitution des Nicotins. Chemische Berichte, 2S, 1904-1912. [Pg.189]

The consistent observation of the arylated products with 92% ee confirms that the enantioselectivity of the asymmetric deprotonation was preserved during the transmetalation with ZnCl2 and retained during the Pd-catalyzed coupling. In fact, the Negishi coupling with 3-bromopyridine (entry 16) was performed at 60 °C, and still provided 26m in 92% ee, which constitutes a formal total synthesis of (R)-nicotine [27]. [Pg.234]

Accelerated hypertension - Nicotine therapy constitutes a risk factor for development of malignant hypertension in patients with accelerated hypertension. Inhaler therapy should be used with caution in these patients and only when the benefits of including nicotine replacement in a smoking cessation program outweigh the risks. [Pg.1334]

The 5-HT3 receptor differs from other monoamine receptor subtypes in constituting a multiunit ion channel analogous to nicotinic acetylcholine, G ABA,, ... [Pg.364]

In tobacco samples examined so far, the levels of NAB were significantly less than those of NNN. In fact, NAB has not yet been detected with certainty in unburned tobacco (15). These findings are in line with the major role of nicotine rather than nornicotine as a precursor to NNN since kinetic studies showed that nornicotine and anabasine were nitrosated at similar rates (25). These rates are relatively high, which suggests that the formation of NNN and NAB could be favored in vivo. When chewing tobacco was incubated with human saliva for 3 hours at 37 and the mixture analyzed for NNN, the concentrations of NNN increased by 44% over that in the chewing tobacco, presumably as a result of further nitrosation (15). Thus, in vivo formation of NNN and NAB could constitute an additional exposure of smokers or chewers to these tobacco specific nitrosamines. [Pg.128]

Alkaloids and Phenols from Tobacco, Tomato, and Potato. Tobacco, tomato, and potato plants contain a number of toxic alkaloids. Probably the most widely studied Is nicotine. The Insecticidal properties of this and other tobacco alkaloids have been reviewed (72). A study of Nlcotlana showed that alkaloids are secreted by trlchomes In the seven species tested (73). Nicotine was the major alkaloid Identified In the trlchome secretion (7A). Anabaslne and nornlcotlne were also Identified In two species (75). Other ether soluable constitutents have also been Identified (76). Aphids were killed by contact with these secretions. Trlchome secretions from Nlcotlana also were... [Pg.76]

Interspecific differences are also known for some naturally occurring poisons. Nicotine, for instance, is used as an insecticide and kills many insect pests at low doses, yet tobacco leaves constitute a normal diet for several species. As indicated earlier, most strains of rabbit eat Belladonna leaves without ill effects, whereas other mammals are easily poisoned. Natural tolerance to cyanide poisoning in millipedes and the high resistance to the powerful axonal blocking tetrodotoxin in puffer fish are examples of the tolerance of animals to the toxins they produce. [Pg.173]

Currently, a wide range of reactive dyes of varying constitution is available which are suitable for many different applications [33], [6, p. 510-516], In most cases, dye is fixed to the substrate under alkaline conditions. However, dyes with phos-phonate groups are applied in an acid dyeing bath, and quaternary nicotinic acid derivatives require neutral conditions. These dyes are used mainly for dyeing PES-CEL blends. [Pg.353]

The Rutaceae oxazoles are evidently derived from /V-nicotinoyl-p-(p-hydroxy)-phenylethylamide (51), with the exception of balsoxin (25) and texamine (26) in which the nicotinoyl moiety is replaced by benzoyl. The condensation of these tyramine and nicotinic acid residues does not represent any major departure from the standard routes of alkaloid biosynthesis in the Rutaceae, for it has long been recognized that the alkaloids of this family are all derived from either phenylalanine (52), tyrosine, (53), or anthranilic acid (54) (22), the latter being the acknowledged precursor to nicotinic acid in most organisms (23). The formation of the putative oxazole precursor 51 or its equivalent therefore constitutes a convergence of the two predominant modes of alkaloid biosynthesis in the family. [Pg.267]

The mixture of AMsopentyl-2-phenylethylamine (Ar49), anabasine (neonicotine, Ar58), anabaseine (nor-nicotine, Ar59), and 2,3 bipyridyl (Ar60) constitutes the trail pheromone of the ant Aphaenogaster rudis245... [Pg.161]

Because it is possible that free acetylcholine may constitute the predominant fraction of the reduced total which is observed after adaptation has occurred, our experiments do not rule out the possibility that cholinergic receptors may acquire tolerance to acetylcholine, as Brodeur and DuBois suggest. We are not prepared to evaluate the importance of increased resistance to carbachol which they present in support of their hypothesis, in view of the strong nicotinic component of the action of that drug. [Pg.95]


See other pages where Nicotine constitution is mentioned: [Pg.280]    [Pg.38]    [Pg.41]    [Pg.43]    [Pg.47]    [Pg.797]    [Pg.797]    [Pg.148]    [Pg.282]    [Pg.97]    [Pg.537]    [Pg.78]    [Pg.79]    [Pg.278]    [Pg.237]    [Pg.243]    [Pg.317]    [Pg.458]    [Pg.55]    [Pg.1197]    [Pg.86]    [Pg.309]    [Pg.324]    [Pg.334]    [Pg.101]    [Pg.915]    [Pg.138]    [Pg.208]    [Pg.211]    [Pg.322]    [Pg.170]    [Pg.90]    [Pg.312]    [Pg.145]    [Pg.488]    [Pg.171]   
See also in sourсe #XX -- [ Pg.38 ]




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