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Clinical pharmacy PharmD program Third level Phytochemistry-1 (PG-504)

Preparation:

The best source is the shells. Carbonate is first removed by hydrochloric

acid. Proteins and other organic impurities are removed with sodium or potassium

hydroxide solution.

Chemical structure:

Chitin is a homo-polymer of 2-acetamido-2-deoxy--D-glucopyranose,

each residue being (1➔4)-linked to form linear chains. It may be considered as

an analogue of cellulose, the hydroxyl groups at C-2 positions of cellulose being

replaced by acetamido-groups, i.e. N-acetyl-D-glucosamine. Each two sugars

units form a disaccharide, chitobiose, which is the partial structure (unit Structure

of Chitin).

Character:

▪ Chitin is colorless powder insoluble in water and in organic solvents, insoluble

in dilute alkali or acids.

▪ Strong acid hydrolysis: Chitin affords glucosamine and acetic acid.

Chitin → Glucosamine + Acetic acid.

▪ Action of strong alkali with heating and under pressure:

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