Grünenthal prohibited the research and manufacture of penicillin by German companies. When the ban was lifted, Grünenthal was the first company to introduce penicillin in the postwar period into the German market. This investment achieved a big financial boost for the company. Chemie Grünenthal synthesized thalidomide in 1954 and acquired a 20-year patent. Soon after obtaining a patent in April 1954, the company started clinical trials, and as early as November 1956, marketed the drug for the treatment of respiratory infections under the trade name Grippex, a combination drug that contained thalidomide, quinine, vitamin C, phenacetin, and acetylsalicylic acid. Researchers at
Tienilic acid the drug and to give covalent binding. The above explanation is a hypothesis. It is still not known (after 15 years) if the reactive intermediate which inactivates the CYP2C9 is the thiophene sulfoxide or the thiophene epoxide. The target on the protein is also not known (could be multiple). However tienilic acid is a good mechanism based inhibitor of CYP2C9 and seems to inactivate it stoichiometrically. Progress in proteomics may one day give the answer. Recent studies indicate that in fact the primary metabolite of tienilic acid (5-OH tienilic acid) cannot be derived from a thiophene-S-oxide intermediate as was previously