V. SPECIFICITY OF ACTION 



47 



TABLE IV 



Biological Activity of Methionine, of Dimethylthetin, and of Some Other 



S-Alkyl Compounds 



Compound 



Prevention of 



Perosis 



Renal 

 lesion 



Fatty 

 liver 



Fowl growth 



Growth with 

 homocystine 



Methionine 



Methionine sulfoxide 



Homomethionine 



Ethionine 



Dimethylthetin 



Methylethylthetin 



Diethylthetin 



Dimethylpropiothetin 



S-Methylcysteine 



S-Ethylcysteine 



S-Methylthioglycolic acid 



+ 25 

 + 25 

 _26 



+ 25 

 _ 1, 15 



TABLE V 

 Biological Activity of Betaine and of Some of Its Derivatives 



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26 G. A. Maw and V. du Vigneaud, J. Biol. Chem. 176, 1037 (1948). 



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