Ha, yes. The "sulfonamide" name may make it sound like just an OH acid/amine swap, but the buried part is that all such antibiotics have a big benzene ring hanging off the other end. The prototype is instead sulfanilamide.

I don't see any merit to this antimicrobial hypothesis, honestly. Muscle catabolism happens whenever protein is needed: what's the microbial threat when a body is starting to starve and disassembles some muscles to get gluconeogenesis going?