Polyhydroxy plant alkaloids

Polyhydroxy Plant Alkaloids as Glycosidase Inhibitors and Their Possible Ecological Role... 

Fellows, L. E., S. V. Evans, R. J. Nash, and E. A. Bell, Polyhydroxy plant alkaloids as glycosidase inhibitors and their possible ecological role, in Natural Resistance of Plants to Pests M. B. Green and P. A. Hedin, eds.), ACS Symposium Series, American Chemical Society, Washington, DC, 1986. 

Aspidiaceae (Fellows et al., 1986 Janzen et al., 1990). These compounds are similar in some regards to coniine (48), a nonhydroxylated piperidine alkaloid. In some legumes, polyhydroxy piperidine alkaloids make up as much as 2% of the dry weight of the plant. These compounds are similar structurally to sugars and are potent inhibitors of glycosidase activity. Specificity varies and some compounds of this series inhibit mannosidases, others fucosidases, and so forth. No glucosidase inhibitor has been reported to present (Fellows et al., 1986) (also see Chapter 15). 

Molyneux, R.J., James, L.F., Ralphs, M.H., Pfister, J.A., Panter, K.E. and Nash, R.J. (1994). Polyhydroxy alkaloid glycosidase inhibitors from poisonous plants of global distibution Analysis and identification, in Colegate, S.M. and Dorling, P.R., Eds., Plant-associated toxins agricultural, phytochemical and ecological aspects, CAB International, Wallingford, pp. 107-112. 

In situations when analysis is required to establish the presence and identity of calystegines in a plant extract it is not necessary to utilize a complex series of chromatographic separations. The plant material can be extracted with methanol or methanol-water and passage over a Dowex 50W-X8 column with dilute ammonium hydroxide as eluant provides substantial purification, yielding the alkaloid fraction, including other polyhydroxy alkaloids, contaminated only by basic amino adds. The extract can thus be rapidly prepared for analysis [29,30]. 

RJ Molyneux, Polyhydroxy indolizidines and related alkaloids. In Methods in Plant Biochemistry Volume 8 - Alkaloids and Sulphur Compounds, PG Waterman, Ed., Academic Press, London, 1993, pp. 511-530. 

In recent years, representatives of 3 new classes of alkaloid have been isolated from both plants and micro-organisms, namely polyhydroxy derivatives of indolizidine, pyrrolidine and piperidine. 

R. J. Molyneux, Polyhydroxy Indolizidines and Related Alkaloids. In Methods in Plant Biochemistry Volume 8-Alkaloids and Sulphur Compounds P. G. Waterman, Ed. Academic Press London, 1993 p511. 

Research progress on sugar-mimic polyhydroxy alkaloids derived from plants 07CJO1337. 

Polyhydroxylated Alkaloids. Polyhydroxy derivatives of pyrrolidine, piperidine, and indolizidine alkaloids have recently been isolated from plants and microorganisms. A number of these compounds have shown potent gluco-sidase inhibitory activity and have generated interest because of their ability to inhibit replication of retroviruses. 

Fellows, L. E., Castanospermine, swainsonine, and related polyhydroxy alkaloids from plants, Phytochem. Soc. North America, Annual Meeting, 1988. 

Reversed-phase HPLC is the method recommended for the screening of plant materiaL in which chromone alkaloids can be present. Mostly C-18 columns were applied with aqueous mobile phases containing high concentrations of buffer at pH 4.5-6.5, modified with methanol or acetonitrile. Polyhydroxy alkaloids of the pyrrohdine, piperidine, pyrro-lizidine, indolizidine, and tropane classes, because of their lack of a suitable chromophore, have rarely been analyzed... 

In the late 1980s a French group interested in the identification of metabolites produced by plant roots that might act as nutritional mediators of specific plant-bacterium relationships discovered the first nortropane-type polyhydroxy alkaloids... 

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