Question

Food preservative sodium benzoate is eliminated from the body as which of the following metabolite?

• A. benzamide
• B. phenyl acetic acid
• C. benzoic acid
• D. Hippuric acid

Hint:

Remember the metabolic fate of common food additives and preservatives. Specifically, recall that benzoic acid, derived from sodium benzoate, is conjugated with glycine in the liver to form hippuric acid, which is then excreted.

Answer 1

The Correct Option is D

Sodium benzoate is a common food preservative.
When ingested, it is rapidly absorbed and then metabolized in the liver.
The primary metabolic pathway for benzoic acid (which is the active form after sodium benzoate is ingested and protonated in the acidic environment of the stomach) involves conjugation with glycine.
This conjugation reaction is catalyzed by the enzyme glycine N-acyltransferase and results in the formation of **hippuric acid** (N-benzoyl glycine).
Hippuric acid is then readily excreted in the urine.
The other options are not the primary metabolites of benzoic acid elimination: - **Benzamide:** Benzoic acid can be converted to benzamide, but this is not the major elimination pathway in humans.
- **Phenyl acetic acid:** This compound is related to other metabolic pathways in the body, not directly to benzoic acid elimination from sodium benzoate.
- **Benzoic acid:** While some benzoic acid might be excreted unchanged, the major pathway involves its conversion to hippuric acid.
Therefore, sodium benzoate is eliminated from the body primarily as hippuric acid.