Question

SAR studies of sulfonamides suggest that antibacterial activity is not lost when the ____.

• A. sulfonamide group is acetylated
• B. amine group is replaced with halogens
• C. aromatic ring is replaced with a non-aromatic moiety
• D. sulfonyl group is replaced by a carboxyl group

Hint:

Acetylated sulfonamides (e.g., acetylsulfamethoxazole) are still active because in vivo they are often hydrolyzed back to the active form.

Answer 1

The Correct Option is A

Structure-Activity Relationship (SAR) of sulfonamides reveals that the antibacterial activity is retained when the sulfonamide group is acetylated. The acetylation improves pharmacokinetic properties without affecting binding to the bacterial enzyme dihydropteroate synthase.