Page 95 - phytochemistry general program
P. 95
Purine alkaloids
Purines are derivatives of a heterocyclic nucleus consists of six membered ring
(pyrimidine) fused to a five membered ring (imidazole).
The most important purine alkaloids are methylated derivatives of xanthine
nucleus. Caffeine is 1, 3, 7 trimethyl xanthine, theobromine is 3, 7 dimethyl
theophylline is 1, 3 xanthine,
xanthine. R1 R2 R3 dimethyl
O R3 Caffeine CH3 CH3 CH3
N
1
7
R1 N
O 3 N Theobromine H CH3 CH3
N
R2 Theophylline
CH3 CH3 H
93
