Page 100 - Phytochemistry 2 (06-PG 605)

Steroidal Alkaloids

1. Solanum glucoalkaloids
A number of Solanum species (Solanaceae) contain some
glycosidal alkaloids which may be considered as nitrogen-
containing natural products related to the steroidal cardiac
glycosides and/or the steroidal saponins in structure.
These alkaloids contain a typical steroidal structure with an
OH group at C3 like the cardiac glycoside which is involved in a
glycosidic linkage with one or more monosaccharide molecules.
Thus, these alkaloids yield upon hydrolysis a basic or
nitrogen –containing steroidal structure as well as one or more
monosaccharides.
The best known of these alkaloids is solanine, isolated from
Solanum tuberosum (Potato) and S. lycopersicum (tomato).
Solanine is glycoside derived from the aglycone solanidine
which is a tertiary base of the following structure:

Solanidine

E
N

CD

A5 B
HO

Solanine = (Solanidine - O – Glucosyl-Galactosyl- Rhamnose)

In the glucoalkaloid solanine the OH at C3 of solanidine is
involved in a glycosidic linkage with a trisaccharide solanose = (D-
glucose, D- galactose and L- rhamnose).

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