IV. lUofllKMlCAL SYSTEMS 425 



Spec. 47141())- I'Ih' priorily of the ( '.riiuaii iiixciitois uiulci- llic paicnt 

 I'oiivenlioii is iiol contested. 



Tlu' liist rniteil States patent granted for tlie .synthesis of thiamine fell 

 to Klingenfiiss (August 16, 1938), whereas the basic patent of WiUiams and 

 nine was issued only five years later (September 7, 1943). 



The circumxention patents of the outsiders did not lead to the industrial 

 use; no thiamine produced on the basis of such processes has appeared on the 

 market (1953). 



E. COISIIMERCIAL FORMS AND PURITY 



Thiamine is sold commercially in the form of two salts, the hydrochloride 

 and the mononitrate. The hydrochloride is official in most of the countries; 

 U.S. Pharmacopoeia XIV (1950, p. 621) and British Pharmacopoeia (1953, 

 p. 42) describe the product in details and the requirements of purity. An 

 especially pure product is sold for the preparation of am puled solutions. 

 The mononitrate is not hygroscopic and therefore is preferred in the food 

 mdustry. Its preparation is described by a Canadian patent ;^^ for the salt 

 itself see U.S.P. XIV, third supplement, p. 11. Its pharmaceutical behavior 

 was investigated by IMacek et al.^^ 



F. PRODUCTION AND PRICES 



The United States, England, and Switzerland are the big producers of 

 thiamine. The following figures show the importance of this vitamin in the 

 U. S.«i 



The price for hydrochloride and mononitrate is the same; there is no 

 higher price for the special product for ampules. Since December 1952, the 

 price has remained stable at $135.00 per kg. 



IV. Biochemical Systems 



B. C. P. JANSEN 



A. ENZYMES 



Everyone who experiments on animals on thiamine-deficient diets is 

 struck by the fact that these animals lose weight every day, while their 



" E. W. Schoeffel (to Merck and Co. Inc.), Canad. Pat. 469,559 (Nov. 21, 1950). 

 *" Thomas J. Macek, B. A. Feller, and E. J. Hunus, /. Am. Pharni. Assoc. Sci. Ed. 



39, 365-69 (1950). 

 «' U. S. Tariff Commission, reports 175 (1951) and 190 (1952) (Synth. Org. Chemicals). 



