Question

Which one is sugar-acid?
a. Vitamin C
b. Vitamin K
c. Vitamin D
d. Vitamin E

Answer 1

Hint: A sugar acid or acidic sugar is nothing but the monosaccharide, with carboxyl end at one side or both sides of the chain, and one of the examples for the sugar acid is aldonic acid, in which aldehyde group is located at the initial end.

Complete answer:
Sugar acids are the oxidation product of monosaccharide, and according to the site on which oxidation occurs, sugar acids are classified into
> Aldonic acid: It is produced by the oxidation of the carbonyl group to the carboxyl group, example for the aldonic acids is gluconic acid from glucose.
> Uronic acid: It is produced by the oxidation of the last carbon which includes glucuronic acid from glucose.
Whereas glucuronic acid has so many uses, they are detoxification reactions, biosynthesis of mucopolysaccharide, metabolism of bilirubin, and excretion of steroids.

- Another example is aldaric acid, it is also called dicarboxylic acid which is a result of oxidation of both carbonyl carbon and last carbon, and an example for this is glucaric acid from glucose.
- Another one is d-L carbonic acid which is also called ascorbic acid, or it is also called vitamin C, and the vitamin c is water-soluble and it is an example of this is gluconic acid.

Hence, the correct answer is option (A).

Note: So in order to understand the sugar acid, it is nothing but monosaccharide or any other sugars, that contain one or more carboxylic acid moieties, whereas apart from the sugar acids, there are some other derivatives called as sugar alcohols are also present.