-Agents that interfere with Nucleic Acid Biosynthesis

I. Sulfonamides the oldest class of antibiotics A) Structures 1) History It is appropriate to give a brief description of the history of the sulfonamides, as they were the first antibiotics developed. Scientists at Bayer in Germany discovered in the early 1930’s that protonsil rubrum, a red dye, would block infections in laboratory animals. Surprisingly, this compound did not block infections in vitro. It was discovered later in the decade that liver enzymes were responsible for metabolizing the inactive dye to the active antibacterial agent sulfanilamide, the parent sulfonamide and the first antibiotic (see figure below). Sulfanilamide is no longer used clinically, but it is important not only for its role as a precursor to the clinically used sulfonamides, but also as a precursor to the sulfonylureas and the sulfonamide anti-glaucoma agents.