Potato Glycoalkaloids and Metabolites:  Roles in the Plant and in the Diet

Abstract

Potatoes, members of the Solanaceae plant family, serve as major, inexpensive low-fat food sources providing energy (starch), high-quality protein, fiber, and vitamins. Potatoes also produce biologically active secondary metabolites, which may have both adverse and beneficial effects in the diet. These include glycoalkaloids, calystegine alkaloids, protease inhibitors, lectins, phenolic compounds, and chlorophyll. Because glycoalkaloids are reported to be involved in host-plant resistance and to have a variety of adverse as well as beneficial effects in cells, animals, and humans, a need exists to develop a clearer understanding of their roles both in the plant and in the diet. To contribute to this effort, this integrated review presents data on the (a) history of glycoalkaloids; (b) glycoalkaloid content in different parts of the potato plant, in processed potato products, and in wild, transgenic, and organic potatoes; (c) biosynthesis, inheritance, plant molecular biology, and glycoalkaloid-plant phytopathogen relationships; (d) dietary significance with special focus on the chemistry, analysis, and nutritional quality of low-glycoalkaloid potato protein; (e) pharmacology and toxicology of the potato glycoalkaloids comprising alpha-chaconine and alpha-solanine and their hydrolysis products (metabolites); (f) anticarcinogenic and other beneficial effects; and (g) possible dietary consequences of concurrent consumption of glycoalkaloids and other biologically active compounds present in fresh and processed potatoes. An enhanced understanding of the multiple and overlapping aspects of glycoalkaloids in the plant and in the diet will benefit producers and consumers of potatoes.

Glycoalkaloids as Biomarkers for Recognition of Cultivated, Wild, and Somatic Hybrids of Potato

“…This was also confirmed by ESI-MS recorded in positive-ion mode. In fact, the spectrum of AG-2 showed a pseudomolecular ion [M þ H] þ at m/z 414, that is the same observed for leptinidine [20], the common aglycone of leptinines [6], and for the 3-O-b-d-glucopyronoside alkaloid found in wild potato species [21]. In the ESI-MS of AG-3, the pseudomolecular ion [M þ H] þ was observed at m/z 416, which is consistent with an aglycone related to solanidine but probably modified in the perhydropyridine ring.…”

“…By contrast, GAs also have positive effects on plant growth and human diet. As recently outlined by Friedman [6], they may provide protection from damages by insects and fungi, and may have anti-inflammatory and anticancer action.…”

The influence of French fries processing on the glycoalkaloid content in coloured-fleshed potatoes

“…glycoalkaloids (Tga), which are potent poisons [5,[8][9][10]. The lethal dose of these components is 3-5 mg kg −1 body weight, with an effect similar to strychnine or arsenic [9,12].…”

Steroidal glycoalkaloids and molluscicidal activity of Solanum asperum Rich. fruits

“…The potato glycoalkaloids may have evolved in nature to protect the plant against phytopathogens and other hostile environments. 15,16 In our previous studies we had found that several species of Solanum, including the unripe fruits of S. asperum have potentially significant molluscicidal activity. 2,3 The crude alkaloid fraction obtained from the active total MeOH extract as well as the pure alkaloids isolated were tested for the molluscicidal activity (Table 2).…”