Page 63 - Phytochemistry 2 (06-PG 605)

- increasing heart muscle contractility and efficiency.
- increasing heart rate.
- increasing blood pressure.
- increasing renal blood flow.
- some anti-inflammatory effects.
- central nervous system stimulatory effect mainly on the medullary
respiratory center.
However, its main therapeutic use is as smooth muscle relaxant,
particularly for the upper respiratory tract.

Test for purine alkaloids
Murexide test https://youtu.be/2xFupfbByJ4

In a porcelain dish containing about 10 mg of xanthine
alkaloid, add 1ml of conc. HCl and about 10 mg of solid potassium
chlorate. Evaporate the mixture to dryness on a water bath, a
yellow residue is left which becomes crimson on further heating.
The colour turns purple when residue is exposed to ammonia
vapour. The colour is destroyed by solution of fixed alkali.

Separation of purine alkaloids
Separation of mixture of caffeine, theobromine and

theophylline depends on the solubility of caffeine in chloroform or
benzene and insolubility of the other two alkaloids (theophylline
and theobromine) in these solvents. Ammonia solution is then
used for isolation of theophylline for theobromine.

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