Petroianu_2014_Pharmazie_69_780

The history of the synthesis of organophosphate inhibitors of cholinesterase starting with the synthesis of tetraethyl-pyrophosphate by Moschnin(e) and de Clermont and leading to the recognition about half a century later of the toxicity of the phosphor ester by Lange and von Krueger has been told in great detail previously. An almost parallel history -described originally by Bo Holmstedt--exists for organophosphonate inhibitors of cholinesterase starting with the synthesis (1898) in Rostock of diethylamido-ethoxy-phosphoryl-cyanide by the pharmacist Adolph Schall (1870-1957), a graduate student of August Michaelis (1847-1916), the re-examination of the chemical structure of the Schall compound (1903) by Michaelis, recognition (1937) of the toxicity of class by Gerhard Schrader (1903-1990) and confirmation (1951) of the structure by Bo Holmstedt (1919-2002). This short report attempts to shed some light on the life of the pharmacists and chemists involved in the synthesis of the first P-CN organophosphonate inhibitor of cholinesterase, focusing on the two less known pharmacists, the graduate students of Professor Michaelis Adolph Schall and Ernst Ratzlaff (1870-1948).