1964 年 84 巻 11 号 p. 1051-1056
Physicochemical properties of orotic acid-amine reaction products were examined, and their structure and state in aqueous solution were observed.
Since the infrared spectrum of the reaction product exhibited absorptions for carboxyl and amine ions, the product was considered to have a structure in which the amine is bonded to the carboxyl group in orotic acid in an ammonium salt type.
Freezing-point depression of the aqueous solution of the reaction product was measured and the reaction product was found to be present in the solution dissociated into orotic acid and ammonium ions.
Thermal examination of the aqueous solution system of orotic acid and amines showed that the heat of mixing of orotic acid and amine is equal to the sum of heat of ionization of each component, and this fact endorses the presumed ionic dissociation of the salt.