390 VITAMIN K GROUP 



coloring matter could be removed by adsorption on carefully added amounts 

 of activated magnesium oxide or carbon. There followed a series of steps 

 which consisted typically in chilling the preparations in various solvents 

 to crystallize out impurities. By such means, for example, there was ob- 

 tained a reddish oil which protected chicks against the hemorrhagic disease 

 when fed at 2 mg. per kilogram of diet.^^ The vitamin was further purified 

 in a molecular still, a fourfold concentration being effected. ^^ The hemor- 

 rhagic disease in chicks was then prevented by 0.5 mg. of the preparation 

 per kilogram of diet. 



Dam and Sch0nheyder^^ concentrated the vitamin by adsorption on cal- 

 cium carbonate or sucrose. Dam et al}^ announced isolation of the vitamin 

 in a highly purified form. Important details in the isolation steps were dis- 

 closed later by Karrer et al}^ 



McKee et al}° used primarily chromatographic adsorption on Decalso 

 and Permutit on a large scale in their isolation of the vitamin from a petro- 

 leum ether extract of alfalfa meal and from putrified fish meal. Details of 

 the procedures were published, ultimately, by Binkley et al.-^ Many other 

 adsorbents were found to be inefficient or destructive for the retention of 

 the vitamin. Repeated adsorptions yielded practically pure vitamin Ki. 



Tishler and Sampson-- have isolated from Bacillus brevis a vitamin K 

 which proved to be identical with the vitamin K2 previously obtained by 

 McKee et al.^^ This isolation was accomplished by reducing the vitamin 

 by hydrosulfite, then extracting it from a petroleum ether layer by dilute 

 potassium hydroxide containing hydrosulfite, recovering the vitamin in 

 petroleum ether on dilution of the alkaline layer with water, and crystal- 

 lizing the product from chloroform and methanol. 



B. CHEMICAL AND PHYSICAL PROPERTIES 



Dam et al}^ reported their yellowish oil preparation to have constant 

 composition and biological activity after repeated chromatographic ad- 

 sorption. It contained carbon 82.2 %, hydrogen 10.7 %, and 2 atoms of 



15 H. J. Almquist, /. Biol. Chevi. 117, 517 (1937). 



16 H. J. Almquist, J. Biol. Chern. 115, 589 (1936). 



'7 H. Dam and F. Sch0nheyder, Biochem. J. 30, 897 (1936). 



•8 H. Dam, A. Geiger, J. Glavind, P. Karrer, W. Karrer, E. E. Rothschild, and H. 



Salomon, Helv. Chim. Acta 22, 310 (1939). 

 1' P. Karrer, A. Geiger, R. Legler, A. Ruegger, and H. Salomon, Helv. Chim. Acta 



22, 1464 (1939). 

 20 R. W. McKee, S. B. Binkley, D. W. MacCorquodale, S. A. Thayer, and E. A. 



Doisy, /. Am. Chem. Sac. 61, 1295 (1939). 

 2» S. B. Binkley, D. W. MacCorquodale, S. A. Thayer, and E. A. Doisy, J. Biol. 



Chem. 130, 219 (1939). 

 22 M. Tishler and W. L. Sampson, Proc. Soc. Exptl. Biol. Med. 68, 136 (1948). 



