Mietzsch, Fritz

Chrysoidine, which was a deep-red dye, had to be grafted to a sulfonylurea derivative (sulfamidochrysoidine) in order to be active. In 1932, it was studied by two chemists, Fritz Mietzsch and Josef Klarer. Testing the new dye on laboratory rats and rabbits infected with streptococci bacteria, Domagk found that it was highly antibacterial but not toxic. It was called Streptozan , but its name soon changed to Prontosil . 

After Allied troops had captured Tunis in May of 1943, the drug fell together with pharmacological reports into the hands of Americans, who confirmed back home its superior efficacy compared to quinine and atabrine. The latter, an acridine dye, also known as mepacrine, originated as well from the discovery programme at Bayer and was first synthesised by Fritz Mietzsch and Hans Mauss and tested by Walter Kikuth around 1932. Bayer s collaboration and distribution partner in the US, Winthrop Chemical Corporation, had increased its production of atabrine by 1944 to annually 3,500 million tablets, with an additional 2 million tablets from the British ICl, in support of Allied forces. The... 

We have seen that azo dyes are used in a variety of applications. One such application led to a discovery that had a profound impact on the field of medicine. Specifically, it was observed that certain bacteria absorbed azo dyes, making them more readily visible under a microscope. In an effort to find an azo dye that might be toxic to bacteria, Fritz Mietzsch and Joseph Klarer (at the German dye company, I.G. Farbenindustrie) began cataloguing azo dyes for possible antibacterial properties. A physician named Gerhard Domagk evaluated the dyes for potential activity, which led to the discovery of the potent antibacterial properties of prontosil. 

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