Nicotinoids Tobacco Alkaloids

The authorities of the scientific species names are only added in the text if a species is not involved in Table 3.1 (Solanaceae), Table 3.2 (Convolvulacae) or Table 3.4 (genus Nicotiana), respectively, where the authorities of the corresponding other species may be found. 

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Nicotinoids with Basic Pyrrolidine or Piperidine Moiety. Nicotinoids are (i) congeners of nicotine, usually minor alkaloids but the term also includes (ii) the principal tobacco alkaloid, nicotine itself. From the structural point of view the nicotinoids may be divided into five groups (Figs. 3.8 and 3.9) ... 

Nicotinoids. Nicotine from tobacco was one of the earliest insecticides and was recommended for use in 1763 as a tea for the destruction of aphids (1,20). Nicotine [54-11 -3], L-l-methyl-2-(3 -pyridyl)pyrrolidine (1) (bp 247°C, d 1.009), is found in the leaves of Nicotiana tobacum and N. rustica (Solanaceae) in amounts ranging from 2 to 14%, and also is found in Duboisia hopwoodii and in Aesclepias syriaca. It occurs as the principal alkaloid along with small amounts of 12 other alkaloids of which nomicotine [494-97-3], 2-(3,-pyridyl)pyrrolidine (2) (bp 270°C, d 1.07 g/mL), and anabasine [494-52-0], l-2-(3 -pyridyl)piperidiae (3) (bp 281°C, d 1.048), are of insecticidal importance (see Alkaloids). Nomicotine occurs as both the D and L forms, the former in D. hopn oodii and the latter commonly predominating in Nicotiana. Anabasine is the chief alkaloid of Anabasis aphylla, where it occurs from 1—2% in the shoots and is found to ca 1% in Nicotianaglauca. 

Interest in alkaloids of the nicotine group appears to be on the increase. A review has appeared covering tobacco-specific nitrosamines, which may be causative factors in tobacco-related cancers. The solution conformation, and proton, deuterium, carbon-13, and nitrogen-15 n.m.r. spectra of nicotine and its 2- and 4-isomers, have been studied. A new synthesis of nornicotine and nicotine has been described, and a quantitative carbon-13 n.m.r. spectral analysis of nicotine that is labelled at positions 1, 2, and 3 with carbon-13 been presented. The synthesis and mass spectrometry of several structurally related nicotinoids have been reported. Nicotine is dehydrogenated on irradiation in benzene solution in the presence of benzophenone to l -methyl-2 -(3-pyri-dyl)pyrrole. ° Nornicotine has been synthesized in four steps from 3-bromo-pyridine and N-3-butenyl-phthalimide, using a palladium-catalysed vinylic... 

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