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

2. Oxidation to Acids: (see latter)

Aldoses are oxidized in four different ways according to the severity and

type of the oxidizing agent:

a) Oxidation to Aldonic Acid (Onic Acids):

By means of Br 2/H 2O, the aldehyde group is oxidized to carboxylic and so

converts aldoses to the corresponding aldonic acids.

Medical Importance : Calcium gluconate (gluconic acid) used as a source of

calcium. These are given I.V. fluids to raise the calcium level.

b) Oxidation to Aldaric Acid (Saccharic acid or Aric Acids):

By means of HNO 3 30%, both the aldehyde group as well as the terminal

primary alcoholic group is oxidized to carboxylic, and these dicarboxylic

acids are known as aldaric acids.

c) Oxidation to Uronic Acid:

In this case, only the terminal primary alcoholic group is oxidized to

carboxylic group. This can be done by protecting the aldehyde group in the

form of glycoside, then oxidizing the primary OH-group by means of NO 2

gas or alkaline permanganate solution, and finally hydrolyzing using dilute

acid to regenerate the original aldehyde group. It is done in one step by the

aid of a specific enzyme to give alduronic acid. e.g. oxidation of glucose

into glucuronic acid.

Medical importance: These are present in the heteropolysaccharides and

glycoproteins. Involved in detoxification of benzoic acid, bilirubin and

certain drugs.

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