237 



Quinones 



additional polyisoprenoid side-chains. There is a marked re- 



CH3O 



CH3O 



CH3 



I 

 (CH2— CH=C— CH2)nH 



Vitamin Kq 



semblance to the previously discovered vitamins K. The follow- 

 ing substances have been isolated, purified, and the structures 

 determined : 



TABLE I 



A survey was made, by using methods sometimes short of iso- 

 lation and purification (paper chromatographic comparisons, 

 spectra, etc. ) of the occurrence of coenzyme Q and of vitamin K 

 in a wide variety of biological types. ^^ Many bacteria contain 

 coenzyme Q. The mycobacteria and streptomycetes seem to 

 contain vitamin K instead. Escherichia coli and chromatium 

 species contain both. Obligate anaerobes such as the Clostridia 



20 R. L. Lester, F. L. Crane and Y. Hatefi, J. Am. Chem. Soc. 80 

 4751 (1958). 



-1 R. L. Lester and F. L. Crane, Biochim. et Biophys. Acta 32 492 

 (1959). 



2- F. L. Crane, Y. Hatefi, R. L. Lester and Carl Widmer, Biochim. 

 et Biophys. Acta 25 220 (1957); idem., ibid. 32 73 (1959). 



23 R. L. Lester and F. L. Crane, /. Biol. Chem. 234 2169 (1959). 



