Glycoalkaloid and Calystegine Contents of Eight Potato Cultivars

Abstract

Diverse procedures have been reported for the separation and analysis by HPLC of the two major glycoalkaloids present in potatoes, alpha-chaconine and alpha-solanine. To further improve the usefulness of the HPLC method, studies were carried out on the influence of several salient parameters on the analysis of the two potato glycoalkaloids. Effects on retention (elution, separation) times of the (a) composition and pH of the mobile phase (acetonitrile and phosphate buffer), (b) concentration of the phosphate buffer, (c) capacity values of column packing of four commercial HPLC amino columns, (d) column temperature were studied. Except for pH, all of the variables significantly influenced the retention times. The results make it possible to select analysis conditions that produce well-separated as well as symmetrical peaks of the two glycoalkaloids. This improved HPLC method (limit of detection of approximately 150 ng) was evaluated with extracts from the cortex of one whole potato variety (May Queen) grown in Japan and the freeze-dried peel and flesh from the following eight cultivars grown in the United States: Atlantic, Dark Red Norland, Ranger Russet, Red Lasoda, Russet Burbank, Russet Norkota, Shepody, and Snowden. In addition, the same samples were analyzed by GC-MS for the presence of two water-soluble nortropane alkaloids, calystegine A(3) and calystegine B(2), reported to be potent glycosidase inhibitors. The following ranges for the eight varieties of total glycoalkaloid and calystegine levels were observed: dry flesh, 5-592 and 6-316 mg/kg; dry peel, 84-2226 and 218-2581 mg/kg; dry whole potatoes, 40-883 and 34-326 mg/kg; wet flesh, 1-148 and 1-68 mg/kg; wet peel, 12-429 and 35-467 mg/kg; wet whole potatoes, 7-187 and 5-68 mg/kg. The possible significance of the results to plant and food sciences is discussed.

Effect of genotype, flesh colour and environment on the glycoalkaloid content in potato tubers from integrated agriculture

“…The TGA contents found by us are in line with other literature data, which also indicates a significant variability in TGA ranges among cultivars. Valcarcel et al (2014) indicated a range from 4 to 957 mg/kg dry matter (DM), Friedman et al (2003) from 5 to 592 mg/kg DM, Deusser et al (2012) from 7 to 466 mg/kg DM and Petersson et al (2013) indicated normal ranges between 5 and 100 mg/kg FM.…”

GLYCOALKALOID METABOLISM1 Is Required for Steroidal Alkaloid Glycosylation and Prevention of Phytotoxicity in Tomato

“…In most cultivated potato species, derivatives of 3-O-glucosylsolanidine are more abundant than those of 3-O-galactosylsolanidine (Friedman et al, 2003). Interestingly, several genotypes of Solanum chacoense exhibit higher relative levels of SGT1 (galactosyltransferase) than of SGT2 (glucosyltransferase), suggesting an opposite SA 3-O-glycosylation ratio (galactosylation/glucosylation) (Krits et al, 2007).…”

Development of Practical HPLC Methods for the Separation and Determination of Eggplant Steroidal Glycoalkaloids and their Aglycones

“…The final method developed for extraction of glycoalkaloids from eggplant material was based on modification and consideration of the varied procedures as applied to the potato by Kuronen et al [27] Saito, [29] Friedman and Levin, [30] Dao and Friedman, [33] Sotelo and Serrano, [36] Friedman et al, [39] and as applied to Solanum sycophanta by Usubillaga et al [55] Analogous to classical precipitation/crystallization procedures for the extraction of solanine from potato, [56] initial attempts were made to extract the glycoalkaloids from eggplant by prescribed methods that involved collection of either a residue [36] or a precipitate. [39] However, such routes were abandoned because acceptable collection of a precipitate/residue of suitable purity and accurately measured mass was either not possible or not feasible, especially when considering that the final method would eventually be applied to a large set of samples.…”

“…[39] However, such routes were abandoned because acceptable collection of a precipitate/residue of suitable purity and accurately measured mass was either not possible or not feasible, especially when considering that the final method would eventually be applied to a large set of samples. Instead, it was deemed preferable to keep the extracts in solution throughout the entire analysis.…”