Quinolizidine alkaloids storage

The biochemistry and physiology of quinolizidine alkaloids is reviewed with respect to their role in lupin meteibolism. Minor roles of the alkaloids may be nitrogen transport and nitrogen storage, but their main function is that of chemical defense. 

Biosynthesis, transport and storage of quinolizidine alkaloids in lupins. Alkaloid concentrations are given as % dry weight. 

Wink, M. and Witte, L. 1991. Storage of quinolizidine alkaloids in Macro-siphum albifrons and Aphis genistae (Homoptera Aphididae). Entomol. 

The internal storage capacity is limited by the number of storage cells. Excreted alkaloids which are dissolved in the medium are exposed to catalytic activities in the medium (e.g., peroxidases) and can thus be degraded as was demonstrated for quinolizidine alkaloids in lupine cell cultures (92). A role for peroxidases in product degradation has been recently demonstrated for indole alkaloids produced by suspension cultures of Tabemaemontana. Reduction of peroxidase activity by removal of Ca ions from the medium resulted in the formation of the alkaloid... 

Alkaloids are produced in nature by some organisms for their physiological purposes. The best known alkaloid producers are plants, but animals and humans also can produce endogenic alkaloids. Moreover, the use of alkaloids by sequestration juice and feed by herbivores and a consumption of storage alkaloids in animal body by carnivores is a process often observed in nature. The problem of narcotism (the use of narcotic bioactive compounds and their consequences) therefore also exists in nature, not only in the human society. It is observed that some insects are narcotized by quinolizidine alkaloids. Some bumblebees can be aggressive to others after visiting alkaloid plants. 

Wink, M., Storage of quinolizidine alkaloids in epidermal tissues, Z. Naturforsch., 41c, 375-380 (1985b). 

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