Page 39 - phytochemistry II -pharmD general

• The alkaloids decolourizes both solution of KMnO4 and bromine water solution,
due to the presence of unsaturated vinyl group.

( + ) Quinidine dextro isomer of quinine.

( - ) Quinine (+) quinidine when warmed with KOH in amyl
alcohol.

Totaquine:

is a combination of total alkaloids of cinchona and is employed for the same
purpose of quinine.

Identification of cinchona alkaloids

1- Thalleioquin test

Few drops of bromine water + solution of quinine salt, + ammonia solution

emerald green colour is produced.

This reaction is sensitive to quinine (0.005% solution give +ve reaction).
• It is also given by quinidine but not with cinchonidine or cinchonine.

2- Fluoresence test
• Quinine and quinidine show blue fluorescence with dil. oxygentated acids
(e.g. sulphuric or phosphoric )

Estimation of Cinchona alkaloids
➢ spectrophotometric method
➢ Gravimetric method

Action and uses of Cinchona alkaloids
• Quinine has antimalarial activity in a dose of 300-600 mg of quinine sulfate

or other salt for 14 days.
• Quinine is used as bitter tonic (tonic water).
• Quinidine is used for treatment of auricular fibrillation in a dose of 200 mg

of quinidine sulfate daily

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