A.1 Solasodine
Synonyms Solancarpidine; Solanidine-S; Purapuridine.
Biological Sources It is obtained from the fruits of Capsicum annuum L. (Solanaceae) (Chili, Paprika, Sweet Peppers); shoots and berries of S. dulcamara L. (Solanaceae) (Bittersweet, Bitter Nightshade, Felonwood); leaves of S. nigrum L. (Solanaceae) (Wonderberry, Black Nightshade, Prairie Huckleberry).
Chemical Structure
(3b, 22a, 25R)-Spirosol-5-en-3-ol; (C27H43NO2).
Isolation It is obtained by the hydrolysis of solasonine which yields solasodine, L-rhamnose, Dgalactose and D-glucose respectively. It is the dehydrated product.
Characteristic Features
(i) It is obtained as hexagonal plates from methanol or by sublimation under high vacuum.
(ii) It has mp 200-202°C; [α]D25 -98o [c = 0.14 in methanol); [α]D –113° (CHCl3); pKb 6.30.
(iii) It is freely soluble in benzene, pyridine, and chloroform; moderately soluble in ethanol, methanol, and acetone; slightly soluble in water and practically insoluble in ether.
Identification Tests (for Solanum Alkaloids)
1. Dissolve 5-10 mg of the alkaloid in a few drops of hot amyl alcohol or ethanol and allow it cool gradually. The appearance of jelly-like product gives the characteristic test of the solanum alkaloids.
2. When a few mg of the alkaloids is treated with antimony trichloride solution in dry chloroform, it gives rise to a distinct red colouration.
3. The solanum alkaloids, in general, produces an instant red-violet colour with formaldehyde (HCHO) and sulphuric acid (H2SO4). This particular test is so distinct and sensitive that it is used for the quantitative estimation of these alkaloids colorimetrically.
Uses It is invariably used as a starting material for steroidal drugs.
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* GGPP = Geranylgeranyl diphosphate
