Cytisine Group

Lupinine-Cytisine Group.—An X-ray analysis of (-)-lupinine hydrochloride and of (+)-epilupinine shows that bond lengths and angles are similar to those of lupinine (cf. Vol. 10, p. 68).16 Aminobenzoate esters of lupinine were prepared by transesterification reactions.17 

Epilupinine esters Epilupinine TV-oxide esters 13-Hydroxymultiflorine esters 

13-Angeloyl-lupanine ) 13-Cinnamoyl-lupanine j Lupinine Sparteine 

There has been considerable interest recently in tricyclic quinolizidine alkaloids containing side-chains, for example angustifoline (1). The conformations of angustifoline and of its dihydro- and desoxy-derivatives have been studied by i.r. and n.m.r. spectroscopy and by X-ray analysis,18 and rearrange-18 M. D. Bratek-Wiewiorowska, J. Mol. Struct., 1979, 55, 69. 

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C. stenopetalus belong to group (c) and contain up to 0-4 per cent, of alkaloids mainly cytisine and methylcytisine with traces of anagyrine in some specimens of the second species. C. monspes-sulanus also belongs to group (c) and contains 0-9 per cent, of alkaloids chiefly methylcytisine with some cytisine and a new alkaloid monspessulanine (p. 146), probably of the lupanine group. (1946). 

In 1931 Ing pointed out that formula (II) and (III) do not contain methyl or potential methyl groups in j ositions 6 and 8 which they occupy in cytisoline. Further, a partially reduced quinoline ought to oxidise easily to a benzenecarboxylic acid and so far the only simple oxidation, products recorded from cytisine were ammonia, oxalic acid and isovaleric acid. Distillation of cytisine with zinc dust or soda-lime yields pyrrole and pyridine, but no quinoline. On these grounds Ing suggested that cytisine should be formulated without a quinoline nucleus, and that the reactions which indicate the presence of an aromatic nucleus in the alkaloid can be accounted for by an a-pyridone ring. This a-pyridone nucleus can... 

Cytisine. This base belongs to the same pharmacological group as nicotine.It is a powerful poison causing nausea, convulsions and death by failure of respiration. The nicotine-like action is shared by A -methyl-cytisine but the latter, according to Scott and Chen, who have made a detailed study of its action, is weaker and has about one-fortieth the toxicity of nicotine. 

Kirch et al. (1995) examined individual plants collected in Corsica, Elba, Sardinia, Liguria, and Provence for alkaloids and observed four groups, one characterized by sparteine [119] (see Fig. 2.34 for structures 119-124), one characterized by lupanine-based alkaloids [120 and 121], one that had a very low level of alkaloid production, and one that lacked sparteine and lupanine-based compounds, but did accumulate other alkaloids such as anagyrine [122], ammodendrine [123], and compounds based on cytisine [124], their outlier group. The distribution of these four chemotypes is presented in Table 2.10. 

This group of alkaloids has a pyridone nucleus and generally takes the tetracyclic or tricyclic form. The a for pyridone alkaloids is L-lysine, while the j8, q> and X the same as for other quinolizidine alkaloids. Quinolizidine alkaloids containing the pyridone nucleus are the P from the (—/-sparteine by cleavage of the C4 unit. The first quinolizidine alkaloid with the pyridone nucleus is tricyclic cytisine, which converts to four cyclic alkaloids. In this synthesis the anagyrine, the most poisonous quinolizidine alkaloid with a pyridone nucleus, has its own synthesis pathway. 

Table 1 Isolation of alkaloids of the lupinine-cytisine-sparteine-matrine group...

Lupanine-Sparteine Group.—A new alkaloid isolated from Echinosophora koreensis was shown to be N-(3-oxobutyl)cytisine (14) by means of spectroscopic studies and by its synthesis from the reaction of cytisine (13) and methyl vinyl... 

The Lupinine-Cytisine—Sparteine—Matrine-Ormosm Group... 

The most common group of alkaloids possessing a quinolizidine nucleus is that of the lupine alkaloids which can simply be classified as bicyclic (lupinine/epilupinine type), tricyclic (cytisine type) or tetracyclic, (sparteine/lupanine or matrine type). Fig. (23). This grouping is made according to structure complexity and without considering biosynthesis, as the detailed biosynthetic pathways are still not completely understood. 

In addition to cytisine, iV-methylcytisine, and pachycarpine a new alkaloid, A (023112603X4 mp 260° [ajj,—305°), was isolated. It contains two lactam groups and a 2(lH)-pyridone ring. Its NMR spectrum is similar to that of cytisine. Hydrogenation gave an octa-hydro derivative (mp 208° [aj — 143°) 232). 

The Lupinine-Cytisine-Sparteine-Matrine-Ormosia Group... 

The Cytisine-Lupanine-Sparteine-Matrine Group and the Onnosia Alkaloids... 

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