Page 65 - Phytochemistry 2 (06-PG 605)

There are considerable variations in alkaloidal contents
among different plants of the same genus.

Tropane alkaloids are all esters of the organic acids, tropic
acid, or substituted derivatives of tropic acid; and the alcoholic
base, tropane-3-ol, or substituted derivative of this base. Tropane
nucleus, which is the parent nucleus, consists of seven-
membered bicyclic ring with a nitrogenous bridge between C-1 and
C-5. Although it contains 2 asymmetric carbons (1&5) yet it is
optically inactive due to internal (or intramolecular) compensation.
Alcoholic bases in tropane alkaloids
1. Tropine: (3-α-hydroxytropane), base of atropine and
hyoscyamine.
2. Scopine: (6, 7-oxytropine), base of hyoscine.
3. Pseudotropine.
4. Nor tropine.
5. Ecgonine: (pseudotropine-2-carboxylic acid), base of cocaine.

71 2 8 R-N
R-N
8 N-R 3 H 2 N-R 3 OR1
1 3H H
OR1 OR1 3 OR1
54 H
65 4 67

Tropine Pseudotropine
R = CH3, R1 = H
R = CH3, R1 = H

7 R-N 1 H COOR 2 R-N COOR 2
2 1 2
H OR1
O N-R 3 N-R 3 H
3H 3 OR1
OR1 O 7 OR1 H
H H
6 6
H
Scopine
Ecgonie
R = CH3, R1 = H R = CH3, R1 = H

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