II. CHEMISTRY 391 



oxygen per molecule. Karrer and Geiger-^ reported a provisional formula of 

 C30-32, H46, 4 8. or 50 , O2, and a molecular weight of 445 to 450. Doisy and 

 coworkers had obtained two final products, one from alfalfa and one from 

 putrified fish meal.-^- 2* The first was a yellow oil and was called Ki; the 

 melting point was given as 53.5 to 54.5^^ and 52.5 to 53.5.^- The vitamin 

 from alfalfa contained carbon 82.76 and 82.54 %, and hydrogen 10.65 and 

 10.66 %. Its molecular weight was determined as 443 to 464, and its probable 

 formula as C32H48-50O2. Almquist and Klose-^ investigated the alkaline deg- 

 radation product of vitamin Ki. This derivative is weakly acid, which 

 facilitates its purification. Analyses and molecular weight determination 

 indicated a provisional formula of C31H50O4. This showed that no appre- 

 ciable fragment of the vitamin had been split off and that 2 oxygen atoms 

 and probably several hydrogen atoms had been added. At least one of the 

 oxygen atoms was phenolic. The empirical formula of vitamin Ki is now 

 known to be C31H46O2, and its molecular weight 450.37. Figure 1 shows the 

 structural formulas of the various forms of vitamin K. 



The vitamin was found to be unstable to light. ^^' ^^ Phenyl isocyanate, 

 cyanic acid, and dinitrobenzoyl chloride, which are reagents for an alcoholic 

 hydroxyl group, did not form an isolatable derivative or affect the activity 

 of the vitamin. Bromine was readily absorbed. Oxidation destroyed activity. 

 A positive nitration test was obtained for an aromatic structure.-^ A di- 

 acetate w^as formed upon reductive acetylation from which the vitamin 

 could be regenerated.^^' -** 



Almquist^^ reported that the vitamin absorbed strongly in the ultraviolet 

 range with considerable destruction. Dam et al}^ reported ultraviolet ab- 

 sorption maxima at 248, 261, 270, and 328 m^. The extinction coefficient, 

 -E'l^., for the 248 line was 280. McKee et alP found the extinction co- 

 efficient at 248 to be 385 and suggested that their product was purer than 

 the one described by Dam et al. However, the biological activity of prepara- 

 tions from these laboratories was found to be equivalent in simultaneous 

 assays by another laboratory .^^ 



Ewing et al.^'^ investigated very carefully the ultraviolet absorption spee- 

 ds P. Karrer and A. Geiger, Helv. Chim. Acta 22, 945 (1939). 



"D. W. MacCorquodale, S. B. Binkely, R. W. McKee, S. A. Thayer, and E. A. 

 Doisy, Proc. Soc. Exptl. Biol. Med. 40, 482 (1939). 



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

 Doisy, /. Biol. Chem. 131, 327 (1939). 



26 H. J. Almquist and A. A. Klose, /. Biol. Chem. 130, 791 (1939). 



" A. A. Klose, H. J. Almquist, and E. Mecchi, .7. Biol. Chem. 125, 681 (1938). 



28 S. B. Binkley, D. W. MacCorquodale, L. C. Cheney, S. A. Thayer, R. W. McKee, 

 and E. A. Doisy, /. Am. Chem. Soc. 61, 1612 (1939). 



" H. J. Almquist and A. A. Klose, J. Biol. Chem. 130, 787 (1939). 



30 D. T. Ewing, J. M. Vandenbelt, and O. Kamm, /. Biol. Chem. 131, 345 (1939). 



