Question

Which of the following is first prodrug for sulfonamide:

• A. Prontocil
• B. Sulfamidochrysodine
• C. Sulfatrim
• D. Trimethoprim

Hint:

Prodrugs like Prontocil are inactive compounds that require metabolic conversion into their active forms, improving bioavailability and reducing side effects.

Answer 1

The Correct Option is A

Prontocil is the first prodrug for sulfonamide. It was developed as an early example of a prodrug, where the compound is metabolized into the active sulfonamide drug in the body.

Answer 2

The question asks which compound was the first prodrug developed for a sulfonamide antibacterial. Let's check each option.

1. Prontocil: Prontosil, an azo dye, was discovered by Gerhard Domagk in 1932 and was found to have antibacterial activity in infected mice, even though it had no antibacterial effect at all when tested directly on bacteria in a test tube. That puzzle was resolved once it was found that the body metabolically cleaves the azo bond of Prontosil, releasing the actual active antibacterial fragment, sulfanilamide. Because Prontosil itself is inactive and only becomes an antibacterial agent after this in-vivo conversion, it is recognised as the first sulfonamide prodrug and the starting point of the entire sulfonamide drug class.
2. Sulfamidochrysodine: This name is not the one conventionally used in pharmacology teaching to identify the first sulfonamide prodrug; the compound historically credited with that discovery, and consistently referred to that way in standard texts, is Prontosil.
3. Sulfatrim: Sulfatrim is a modern trade name for the fixed-dose combination of sulfamethoxazole and trimethoprim (co-trimoxazole), developed decades after the original sulfonamide breakthrough, so it cannot be the first sulfonamide prodrug.
4. Trimethoprim: Trimethoprim is not a sulfonamide at all; it is a diaminopyrimidine that inhibits dihydrofolate reductase and is typically combined with a sulfonamide for synergistic action, rather than being a prodrug of one.

Since Prontosil was the first compound shown to be metabolised in the body into an active sulfonamide, it holds the historical place of the first sulfonamide prodrug.

Therefore, the correct answer is Prontocil.