Page 96 - phytochemistry II -pharmD general
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which is gelatinous in presence of ammonia solution. Upon warming with
ammonia, gelatinous precipitate dissolves and by boiling for sometimes, granular
insoluble precipitate is formed. This reaction can be used for separation of
theobromine from caffeine.
Uses
Theobromine is diuretic especially in cardiac oedema.
c. Theophylline
It occurs in small quantities in tea leaves. The amount of theophylline in tea
leaves is too small to be of commercial importance and consequently, it is made
synthetically.
Properties
Theophylline occurs as white, odorless crystalline powder, sparingly soluble
in water (1:120), soluble in alcohol (1:80), very sparingly soluble in ether and
chloroform and insoluble in benzene. It is easily soluble in ammonia. It forms
insoluble salts with silver nitrate. The formation of silver salt is usually used in the
isolation of theophylline from tea leaves.
Uses and Pharmacological actions of theophylline involve
- relaxing bronchial smooth muscle.
- increasing heart muscle contractility and efficiency.
- increasing heart rate.
- increasing blood pressure.
- increasing renal blood flow.
- 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. Thus it is used in therapy for respiratory diseases under a
variety of brand names.
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