319 Amino Acids and Related Compounds 



HC C CH— CH-CH,— O— P H,0 HC=C— CH.— C— CHj— O— P 



N NH OH OH -^-^ N NH O 



c c 



H H 



Imidazole glycerol Imidazoleacetol 



Phosphate Phosphate 



glutamate 



— » a-ketoglutarate 



H3PO, + 



HC=^C— CHo— CH— CH,— OH H,0 HC=— C— CH,— CH— CH2— O— P 



N NH NH2 ^ '^— N NH NH2 



\/ \/ 



C C 



H H 



L-Histidinol L-Histidinol 



2DPN 



2DPNH 



HoO Phosphate 



© 

 2H 



HC=C— CH,— CH— COOH 



N NH NH> 



\/ 

 C 

 H 



Histidine 

 It is interesting that the final stages of this synthesis differ 

 from those in the tryptophan sequence when some of the inter- 

 mediates are so closely related. Perhaps in some species a 

 lesser difference will be found. 



Histidine is converted to ergothioneine in microorganisms by 

 methylation to form hercynine, followed by direct introduction 

 of the thiol group. 



663 Glycine, C.H,,O.N, colorless crystals, m.p. -'280-290° (dec.) 



(rapid heating). 



H,N— CH,— COOH 

 Widely distributed. 



664 Sarcosine, C3H7O0N, colorless crystals, m.p. 212° (dec). 



CH,NHCH,COOH 



Cladonia sylvatica 



Also a component of the actinomycin antibiotics. 

 P. Linko, M. Alfthan, J. K. Miettinen and Artturi I. Virtanen, 

 Acta Chem. Scarid. 7 1310 ri953). 



