Alkaloids, polyamine derived

Some of the plant species contain many different alkaloids, e.g., Lunaria biennis Moench. (Cruciferaceae). The investigation of this field of plant metabolites seems to have been done randomly and not systematically. Furthermore, the occurrence of di- and polyamine derivatives in many cultivated plants is apparent (123). Their structural differences from the more complicated alkaloids are not very large. It appears very probable that many more plants and animals contain di- and polyamine alkaloids than are known today. 

Polyamine-Derived Alkaloids in Plants Molecular Elucidation of Biosynthesis... 

Biochemical and molecular studies have led to the elucidation of a number of key enzymatic steps involved in polyamine-derived alkaloid biosynthesis. Based on their phylogenetic relationships, alkaloid biosynthetic enzymes are presumed to have evolved from structurally related but catalytically distinct proteins, particularly... 

Work also prepared a series of carbinolamines and polyamines without a quinoline nucleus but, in other respects, conforming in type and range of molecular weight, with quinoline compounds known to possess plasmocidal activity. As none of these were active, it seems clear that the quinoline nucleus in the cinchona alkaloids and in certain synthetic anti-malarials is a potent factor in the production of plasmocidal action. Later the same author made (1942) a series of lepidylamine derivatives of the form R. Q. CHj. NH[CH2] . NEtj, which were found to be inactive, in spite of their similarity to the active examples of the type R. Q. NH[CH2] . NEt2 prepared by Magidson and Rubtzow. Rubtzow (1939) has also shown that an isomeride of dihydroquinine (II) with the quinuclidine nucleus attached via the carbinol group at C in the quinoline nucleus was inactive in an infection of Plasmodium prcecox in finches. 

When plants undergo various stresses, certain secondary metabolites, including defense compounds, accumulate. Several secondary metabolites such as terpenoid indole alkaloids, indole glucosinolate, nicotine alkaloids, and polyamines are known to accumulate through the induction of biosynthetic genes by jasmonates.898-900 MeJA also induces genes involved in the formation of tryptophan derivatives, terpenoid indole alkaloids.901 These compounds are known to be involved in defense response to pathogen attack as phytoalexins. 

A much greater number of acyclic polyamines have been described from spiders. These compounds feature short linear chains consisting of three to five carbons atoms, which are probably derived from amino acids. Spider-derived polyamines will therefore be discussed together with other amino acid-derived alkaloids and amines in Section 2.04.6.5. 

Most pyrrolizidine alkaloids are esters of basic alcohols known as necine bases. The most frequently studied pyrrolizidine alkaloids are formed from the polyamines, putrescine and spermidine, and possess one of three common necine bases retronecine, heliotridine, and otonecine. Putrescine is utilized exclusively as a substrate in secondary metabolism, whereas spermidine is a universal cell-growth factor involved in many physiological processes in eukaryotes. Spermidine biosynthesis begins with the decarboxylation of SAM by SAM decarboxylase 165). The aminopropyl group is then transferred from decarboxylated SAM to putrescine by spermidine synthase to form spermidine (Scheme 5). Putrescine can be produced from ornithine by ODC. However, putrescine is derived from the arginine-agmatine pathway in pyrrolizidine alkaloid-producing plants due to the absence of ODC activity 166). 

Also, in this chapter, the polyamine alkaloids, such as ephedradine and kukoamine, which contain a polyamine unit derived from putrescine and are biosynthesized by decarboxylation of ornithine, will be discussed. Furthermore, atropine and cocaine, which are biosynthesized via the AT-methyl-l-pyrrolinium ion and formed by methylation of putrescine followed by cyclization, and tetrodotoxin, which was once considered to be biosynthesized from arginine, will be discussed. 

Polyamines, Alkaloids, and Various Nitrogen-Containing Derivatives... 

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