Solanum steroid alkaloids glycoalkaloid

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. 

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. 

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. 

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%). 

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). 

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). 

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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