The Telekom Affair – In May 2007, several former riders admitted to using banned substances (including EPO ) while riding for the team in the mid-1990s, including Erik Zabel , Rolf Aldag , Brian Holm ,  Bjarne Riis ,  Bert Dietz , Udo Bölts and Christian Henn including the seasons in which Riis and Jan Ullrich won the Tour de France.  Team doctors Andreas Schmid and Lothar Heinrich also confessed to participating and administering banned substances. The latter was Team Telekom's sporting director until 3 May 2007, when he was suspended following allegations published in former team member Jef d'Hont 's book. 
Valproic acid was first synthesized in 1882 by Beverly S. Burton as an analogue of valeric acid , found naturally in valerian .  Valproic acid is a carboxylic acid , a clear liquid at room temperature. For many decades, its only use was in laboratories as a "metabolically inert" solvent for organic compounds. In 1962, the French researcher Pierre Eymard serendipitously discovered the anticonvulsant properties of valproic acid while using it as a vehicle for a number of other compounds that were being screened for antiseizure activity. He found it prevented pentylenetetrazol -induced convulsions in laboratory rats .  It was approved as an antiepileptic drug in 1967 in France and has become the most widely prescribed antiepileptic drug worldwide.  Valproic acid has also been used for migraine prophylaxis and bipolar disorder.