Glycoalkaloid from potato

Friedman, M., Lee, K. R., Kim, H. J., Lee, 1. S., Kozukue, N. (2005). Anticarcinogenic effects of glycoalkaloids from potatoes against human cervical, liver, lymphoma, and stomach cancer cells. J. Agric. Food Chem., 53, 6162-6169. 

Extraction of glycoalkaloids from freeze-dried potatoes for HPLC... 

Fig. 10,7. Separation of glycoalkaloids from a potato meal extract...

Some Solanum glycoalkaloids have been characterized by GC-MS analysis of their permethyl derivatives (60, 170 cf. 370) and determined in living plants and herbarium specimens by use of a radioimmunoassay (371). Like digitonin and a-tomatine, the steroidal gjycoalkaloid mixture from potato (a-solanine and a-chaconine) is able to complex with 3/ -hydroxysterols in vitro (370) which can be used for the quantitative analysis of these alkaloids (379). 

It has been suggested that the potato beetle - toxic and distasteful for potential predators - sequesters glycoalkaloids from the foliage of potatoes or other glycoal-kaloid-containing solanaceous species. However, the repellency to predators is... 

Van Gelder WMJ, Scheffer JJC (1991) Transmission of steroidal glycoalkaloids from Solanum vemei to the cultivated potato. Phytochemistry 30 165-168 Vdzquez A, Ferreira F, Moyna P, Kenne L (1999) Structural elucidation of glycosides from Solanum amygdalifolium. Phytochem Anal 10 194-197... 

Assessment of whether a chemical has the potential to cause adverse effects in humans arises usually from direct observation of an effect in animals or humans, such as the acute poisoning episodes that have occurred when potatoes contain high levels of glycoalkaloids. Epidemiological studies have also been used to infer a possible relationship between intake of a particular type of food, or constituent of that food, and the potential to cause an adverse effect. Such observations led to the characterisation of the aflatoxins as human carcinogens. However, natural toxic substances that occur in plant foods have often been identified through observations in animals, particularly farm animals. It was observations of adverse effects in farm animals that led to the further characterisation of the phytoestrogens and the mycotoxins. In other instances, the concern arises from the chemical similarity to other known toxins. 

Sanford L L, Deahl K L, Sinde S L and Ladd Jr T L (1992), Glycoalkaloid content in tubers from Solanum tuberosum populations selected for potato leafhopper resistance , Am Potato J, 69, 693-703. 

The fruit of a number of solanaceous plants, including tomato Lycopersicon esculentum), potato Solanum tuberosum) and eggplant Solarium melongena esculentum), have cholinesterase-inhibiting effects (Krasowski et al. 1997). They contain solanaceous glycoalkaloids o-solanine and o-chaconine, which are triglycosides of solanidine, a steroidal alkaloid derived from cholesterol. They are the only plant chemicals known to inhibit both acetlycholinesterase and butyrylcholinesterase, both in vitro and in vivo. 

Sorensen, K. K., Kirk, H. G., Olsson, K, Labouriau, R., Christiansen, J. (2008). A major QTL and an SSR marker associated with glycoalkaloid content in potato tubers from Solanum tuberosum x S. sparsipilum located on chromosome I. Theoretical and Applied Genetics, 117, 1-9. 

This limited overview on the analysis of four classes of the following secondary potato metabolites is, except for anthocyanins, largely limited to our own studies of glycoalkaloids, calystegine alkaloids, and phenolic compounds. Because interest in these potato constituents arises from potential health benefits and occasional toxicity, we also include in this overview a brief discussion of these aspects that relate to composition and a description of experimental methods. The interested reader should consult the cited references for an entry into the extensive worldwide literature on the diverse analytical and biological aspects for these metabolites. 

The two potato glycoalkaloids in the potato extract were identified as follows (a) comparison of thin-layer chromatography of standards a-chaconine and a-solanine and of samples of each peak collected from the HPLC column containing the individual glycoalkaloids and (b) HCl hydrolysis of the HPLC samples into sugars and the aglycon solanidine. These were identified by GLC-MS (Kozukue et al., 1999, 2008 Kozukue and Friedman, 2003). 

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