INTRODUCTION 753 



Thayci', and Doisy'-*"' rtiported the stru(;ture of vitamin K2 the following year. 



The active group for \ntaniin K activity was shown by Ansbacher and 

 Feniholz'-'^ to bo 2-incthyl-l,-l-naphtho(|uinonc. This grouping occurs in 

 ])()th vitamins Ki and K'>, and their liiopotency was found to ])e proportional 

 to the amount of 2-methyl-l,4-naphthoquinone which could be derived 

 from their molecules. Fieser, Tishler, and Sampson-^ made a thorough and 

 comprehensive study of the biologic activity of a wide variety of compounds 

 including the naphthoquinones, naphthohydroquuiones, esters and ethers 

 of the hydroquinones and of many related compounds. For a more com- 

 plete discussion of the structural relationships of vitamui K, the reader is 

 referred to The Lipids, Vol. I, pages 832-859. Excellent reviews on vita- 

 min K include those of Wohlisch,-^ Riegel,^" Grossman,*^ Brinkhous,^- and 

 Rosenberg.^" The more recent reviews by the authorities in the field 

 include those of Almquist,^* Harris et al.,^ Dam,*^-*^ and Doisy et al.^ 



The formulas of the vitamin K-active compounds are shown below. 



O 

 C C 



HC « C -^ C— CHs 



HC^ C =C— CHoCH^CCHoCHoCHaCHCHoCHaCH.CHCH.CHoCHaCHCHs 



C C CH3 CH3 CH3 CH3 



H 



Vitamin Ki 

 (2-Methyl-3-phyt3^1-l,4-naphthoquinone) 



« S. B. Binkley, R. W. McKee, S. A. Thayer, and E. A. Doisy, ./. Biol Chem., 133, 

 721-729(1940). 



" S. Ansbacher and E. Fernholz, J. Am. Chem. Soc, 61, 1924-1925 (1939). 



28 L. F. Fieser, M. Tishler, and W. L. Sampson, /. Biol. Chem., 137, 659-692 (1941 ). 



" E. WohUsch, Ergeh. Physiol, biol. Chem. exptl. Pharmakol, 43, 174-370 (1940). 



30 B. Riegel, Ergeb. Physiol, biol. Chem. exptl. Pharmakol, 43, 133-173 (1940). 



31 A. M. Grossman, /. PediaL, 16, 239-253 (1940). 

 '2 K. M. Brinkhous, Medicine, 19, 329-416 (19401 



33 H. R. Rosenberg, Chemistry and Physiology of the Vitamins, Interscience, New York, 

 1945. 



3^ H. J. Almquist, Physiol Revs., 21, 194-216 (1941). 



3* R. L. Harris, H. J. Almquist, and C. A. Owen, Jr., Vitamin K. Group, in W. H. 

 Sebrell, Jr. and R. S. Harris, The Vitamins, Vol. II, Academic Press, Inc., New York, 

 1954, pp. 387-448. 



3« H. Dam, Advances in Enzymol, 2, 285-324 (1942). 



3^ H. Dam, Vitamins and Hormones, 6, 27-53 (1948). 



3« E. A. Doisv, S. B. Binkley, and S. A. Thaver, Chem. Revs., 28, 477-517 (1941 ). 



