58 CHOLINE 



VIII. Standardization of Activity 



WENDELL H. GRIFFITH and JOSEPH F. NYC 



Choline is a fairly stable chemical that participates directly and in- 

 directly in metabolic reactions. The factors that control its synthesis by 

 transmethylation and by formate-to-methyl synthesis are not known defi- 

 nitely. Standardization of activity in the usual sense is, therefore, not 

 feasible. 



IX. Occurrence 



WENDELL H. GRIFFITH and JOSEPH F. NYC 



The total choline present in typical foods (Tables VII and VIII) has 

 been determined by Engel,^ and the amount in common meat cuts (Table 

 IX) by Mclntire et air Clrains and milled wheat products were also ana- 

 lyzed by Glick'^ (Table X). The examination of foodstuffs in India^ and in 

 Sweden^ has given values similar to those in the tables. Egg yolk, glandular 

 meats, and brain are the richest animal sources, and the germ of cereals, 

 legumes, and seed-oil meals are the best plant sources. Of interest is the 

 relatively high le\'el in patent flour. 



The choline content of fresh and of processed milk has been studied in 

 several lal)oratories.'^'** According to Hodson^ little loss occurs in the prepa- 

 ration of dried milk, although Marquez'^ reported that in both raw and 

 pasteurized milk no choline was present after standing 48 hours at room 

 temperature. Most of the choline of milk is found in the aqueous rather 

 than the cream layer .^ 



Sadhu^ noted a slight positive correlation between the choline content 

 of the brain and the lactose content of the milk of nine species of mammals 

 whereas a high correlation was found between the lactose level and the 

 brain cerebrosides. He suggested that sphingosine can react reversibly 



1 R. W. Engel, /. Nutrition 25, 441 (1943). 



2 J. M. Mclntire, B. S. Schweigert, and C. A. Elvehjem, /. Nutrition 28, 219 (194-t). 

 ^D. Glick, Cereal Chem. 22, 95 (1945). 



*H. Chattopadhyay and S. Banerjee, Food ReSr-arch 16, 230 (1591). 

 s N. E. Borglin, Acta Pharmakol. Toxicol. 3, Suppl. 1 (1947). 

 6 A. Z. Hodson, J. Nutrition 29, 137 (1945). 



^ V. M. Marquez, S?hool Hyg. and Publ. Health, Biochem. Dept., Johns Hoi)ldns 

 University (Separate), March 1942. 



8 E. Kahane and J. L^vy, Bull. soc. chiin. biol. 27, 72 (1945); Compt. rend. 220, 97 

 (1945). 



9 D. P. Sadhu, /. Dairy Sci. 31, 347 (1948). 



