Solanum steroidal glycoalkaloids

Roddiek, J. G., Weissenberg, M., Leonard, A. L. (2001). Membrane disruption and enzyme inhibition by naturally-oeeurring and modified ehaeotriose-eontaining Solanum steroidal glycoalkaloids. Phytochemistry, 56,603-610. 

Potato alkaloids. The cultivated potato (Solanum tuberosum L.) contains two major glycoalkaloids, a-chaconine and a-solanine. The two components both contain the C i steroidal aglycone solanidine they differ only in the sugar moieties included in the trisaccharide part. a-Solanine and a-chaconine form up to 95% of the glycoalkaloids present in potatoes. Data on occurrence, chemistry, analysis, and toxicology of the steroidal glycoalkaloids present in potatoes have been comprehensively reviewed (77, 75). 

Antifungal activity has been demonstrated mainly in two groups of plant steroids, glycoalkaloids of the Solanum type and saponins. Members of both groups are comprised of a steroidal aglycone... 

Van Gelder, W.M.J. Steroidal glycoalkaloid in Solanum species Consequences for potatoes breeding and food safety, Ph.D. Thesis University of Wageningen Holland, 1989. 

Solasodine see a-Solasonine. a-Solasonine, solasonine a Solanum steroid alkaloid occurring in many species of Solanum, e.g. S. sodomeum, S. aviculare, S. laciniatum and X nigrum. It is a glycoalkaloid containing the aglycon, salaso-dine [(22R 25R)-spirosol-5-ene-3p-ol], M, 413.67, m.p. 201 °C, [aJo -107° (CHCI3) and a branched trisaccharide. 

Pregnane Type Sapogenins/Saponins. 5a-Pregn-16-en-3P-ol-20-one was isolated from Solanum pimpinellifolium Jussl. sub nom. Lycopersicon pimpinellifo-lium (Jussl.) Mill, by Schreiber and Aurich (1966) and also by Bennett et al. (1967). The authors speculated that this aglycone could be a metabolite of the steroidal glycoalkaloid tomatine. Heftmann and Schwimmer (1972) added that... 

Schulz D, Eilert U, Willker W, Leibfritz D, Ehmke A (1992) Steroidal glycoalkaloids from Solanum triflorum. Abstract Book, 40th Annual Congress on Medicinal Plant Research, Trieste, Italy, p 133... 

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... 

Weissenberg M, Levy A, Svoboda JA, Ishaaya I (1998) The effect of some Solanum steroidal alkaloids and glycoalkaloids on larvae of the red flour beetle, Tribolium castaneum, and the tobacco horn worm, Manduca sexta. Phytochemistry 47 203-209 Weyerstahl P, Christiansen C, MarschaU H (1992) Isolation and synthesis of isohumbertiol, the first naturally occurring sesquiterpene alcohol with a humbertiane skeleton. Liebigs Ann Chem 1325-1328... 

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. 

Figure 1. Aglycone skeletons of fungitoxic steroidal saponins and Solanum glycoalkaloids.

A subgroup of the steroidal saponins are the glycoalkaloids, in which the aglycone is a steroidal alkaloid (contains a nitrogen atom). The most common source of these compounds is the Solanum genus, including the common potato Solanum tuberosum. 

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). 

Table 7.3 Steroidal alkaloids (alkammes) alphabetically listed within the different structural types For 41 out of altogether 115 compounds from Solanum spp. (113 compounds), Lycianthes biflora, and Saracha punctata (one compound each) at least one corresponding glycoalkaloid was found and structurally elucidated, i.e., for 36% of the alkamines also corresponding glycosides are known (continued)...

Hydroxy-spirosolanes (Fig. 7.19). Solasodine is the dominating congener of the 25/ -series (22ot/V-configurated) and even the most frequent individual aglycone of all types of solanaceous glycoalkaloids. It was detected unequivocally in 207 out of 367 steroidal alkaloid-positive Solanum spp. (56%). 

Armer CA (2004) Colorado potato beetle toxins revisited Evidence the beetle does not sequester host plant glycoalkaloids. J Chem Ecol 30 883-888 Arthan D, Svasti J, Kittakoop P, Pittayakhachonwut D, Tanticharoen M, Thebtaranonth Y (2002) Antiviral isoflavonoid sulfate and steroidal glycosides from the fruits of Solanum torvum. Phytochemistry 59 459 63... 

Ferro EA, Alvarenga NL, Ibarrola DA, HeUion-Ibarrola MC, Ravelo AG (2005) A new steroidal saponin from Solanum sisymbrifolium roots. Fitoterapia 76 577-579 Fewell AM, Roddick JG (1997) Potato glycoalkaloid impairment of fungtil development. Mycol Res 101 597-603... 

Phytochemical screening of the methanolic and aqueous extracts of the fruit and crown of Solanum Melongena revealed the presence of alkaloids, saponins, steroids, tannins/ phenolics, flavonoids, proteins and carbohydrates. Ascorbic acid and phenolics both which are powerful antioxidants were also present in fruit. The presence of saponins and glycoalkaloids protect the plant from microbial pathogens [23]. 

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