569 Pteridines and Flavines 



1059 Citrovoriim Factor (Folinic Acid-SF, Leucovorin, N^-Formyltet- 

 rahydrofolic Acid) C^H.-fi^N- (Trihydrate) : Buff crys- 

 tals, m.p. 248-250° (dec), [a],,-" +16.76 (c 3.52 on 

 anhydrous basis in 5% sodium bicarbonate solution). 



C— H O COOH 



OH I ^^ II I 



I ,CH..— NH— (/ \)— C— NH— CH 



CH 



I 

 H2N H CH2 



1 

 COOH 





Yeasts (probably widely distributed) 



The corresponding compound with the formyl group 

 transferred to the amine group of the p-aminobenzoic acid 

 moiety (Nj,,) is also known. 



C. H. Hill and M. L. Scott, J. Biol. Chem. 196 195 (1952). 

 (Isolation from brewers' yeast) 



A. G. M. Sjostrom and L. E. Ericson, Acta Chem. Scand. 7 

 870 (1953). (Isolation from eight lichens) 



Donna B. Cosulick, Barbara Roth, James M. Smith, Jr., 

 Martin E. Hultquist and Robert P. Parker, /. Am. Chem,. Soc. 

 74 3252 ( 1 952 ) . ( Structure ) 



1060 Flavine-Adenine-Dinucleotide, CotH^sOi^NciPo, amorphous white 

 powder. 



NH2 



N 





o 



li II 



CHo— O— P— O— P— O— CH, 



1 I 

 OH OH 



HC— OH OH OH 



I 

 HC— OH 



I 

 HC— OH 



I 

 CHo 



CH3 I o 



CH, 



