Prontosil, the first commercially available antibacterial antibiotic (with a relatively broad effect against Gram-positive cocci but not against enterobacteria), was developed by a research team at the Bayer Laboratories of the IG Farben conglomerate in Germany. The discovery and development of this first sulfonamide drug opened a new era in medicine. History Sulfonamidochrysoidine (KI-730), first synthesized by Bayer chemists Josef Klarer and Fritz Mietzsch, was tested and found effective agai… (More on Prontosil)