Page 104 - phytochemistry general program

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).
Another Solanum steroidal alkaloid is solasodine, that exist in solanum
species both as a genin and as the trioside. The structure of the genin solasodine
demonstrates the close similarity to the structure of the steroidal saponins. The
following structures show that solasodine is exactly the N- analogue of diosgenin,

a steroidal sapogenin.

25 25

F F

E ON E OO

CD CD

A5 B HO A5 B
HO
Diosgenin
Solasodine (In Dioscoria & Trigonella species)
(The N-Analogues of Diosgenin)

Solanum alkaloids have no or little physiological activity. However they are of
great commercial value as starting material (precursors) for the synthesis of the

steroidal sex hormones and the corticoids.

2. Veratrum alkaloids

Veratrum species Fam. Liliaceae contain alkaloids of typical or atypical
steroidal structures; these alkaloids may be distinguished into two chemical types.

I)- The first type:
Includes simple typical or atypical steroidal alkamines. These alkamines
contain in their structure one or two hydroxyl groups but these hydroxyl groups are
not esterified by acids (not esters). They also have a double bond between C5

and C6.
From the formulas it is clear that some of these alkamines are typical
steroids (rubijervine and isorubijervine). While the others (jervine and veratramine)

are atypical steroids (they are C-Nor D-homo steroids).
These bases are found in plant extracts partly as free alkamines and partly as

glycosides (with one molecule of glucose at the OH of C3).

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