60 UNITY AND DIVERSITY IN BIOCHEMISTRY 



yellow solution having a yellow-green fluorescence. With heavy metals it 

 forms sparingly soluble salts. When heated, it decomposes at 274°. It is 

 stable to oxidizing agents. Under the influence of light, it is transformed, 

 depending on the conditions, either into lumilactoflavin or lumiflavin (a 

 derivative of isolloxazine, p. 54), or into lumichrome (a derivative of 

 alloxazine). Riboflavin, or vitamin B^^, is not a true nucleoside, since the 

 isoalloxazine in it is not combined with ribose, but with ribitol, the 

 corresponding alcohol. 



H H 



I \ 



CNN 



<^ \ / ^ / \ 



H..C— C C C CO 



I II i I 



H.C— C C C NH 



% y ^ ^ \ y 



C N C 



I II 



H O 



Lumichrome 



H 



HO— C— H {">') 

 I 

 H— C— OH (4') 



H— C-OH (3') 



H— C— OH (2') 



I 

 H— C— H (!') 



H 



CNN 



HaC— C 7 C C 2 CO 



^ I II I I 



H3C— C 6 C C 3 NH 



6,7-dimethyl-9-D-ribityl-isoalIoxazine or vitamin B2 



REFERENCES 



Baddiley, J. (1955). Chemistry of nucleosides and nucleotides, in E. Chargaff 

 and J. N. Davidson, The Nucleic Acids, Vol. I, pp 137-190 Academic Press, 

 New York. 



PiGMAN, W. W. & GoEPP, R. M. (1948) Chemistry of the Carbohydrates, Academic 

 Press, New York. 



