THE OCCUEREHCE AND SIGaHFICANCE OF TRIMEIHYIAMniE 

 OXIDE IN MARINE ANIMALS 



by 



Herman S. GroalDger 

 Bloeheolst 

 U. S. Fish and Wildlife Service 

 Seattle, Washington 



IHTRODUC?nON 



The occurrence of trlme thylami. ne oxide in laarine animals is 

 interesting because of its indirect effect on the quality of seafood. 



The purposes of this review are (l) to coaipile pertinent 

 information on the occurrence of trime thylnmi, ne oxide in marine animals 

 and (2) to examine current ideas on the origin and function of trimethyl- 

 amine oxide in these animals. 



CHEMICAL NATURE OF TRIMETHYLAMINE OXIDE 



Trimethylamine oxide has the following structure: 



The oxide is a solid with a melting point of 257* C. It is soluble in 

 water, acting as a weak base with a dissociation constant for the cationie 

 acid of 1^.65 (Ronald and Jakobsen 19^1-7). The salts of the oxide have a 

 marked buffering action in the region of pH 4.5 (Castell 1949a* Suyama 1958)' 

 In aqueous solution, the oxide is stable between pH 3 and 9 when heated at 

 107* for 7 hours (Ronald and Jakobsen 19^7). The oxide can act as a 

 hydrogen acceptor; it is reduced to trimethylamine in the presence of iron 

 or hemoglobin catalyst and cysteine (Vaisey 1956) and also by an enzyme 

 triamineoxidease (Tarr 19^0), which is present in a nuniber of different 

 species of bacteria (Castell 1949b, Tarr 1939) • Trimethylamine oxide is 

 not toxic to animals. 



OCCURREHCE 



Trimethylamine oxide is found with other kinds of noixprotein 

 nitrogen compounds in the fluids and tissues of marine and fresh-water 

 animals. Although this report is concerned primarily with trimethylamine 



