OCCURRENCE OF THE K VITAMIN'S 831 



ing year the structure of vitamin K2 was demonstrated by Binkley, McKee, 

 Thayer, and Doisy.^^ 



Even before the structure of the vitamins K had been estabhshed, Ans- 

 bacher and Fernholz^^ discovered the antihemorrhagic activity of 2- 

 methyl-l,4-naphthoquinone. This preceded an extensive study of a wide 

 variety of naphthoquinones, naphthohydroquinones, esters and ethers of 

 the hydroquinones, and of many related compounds, which was carried out 

 by Fieser, Tishler, and Sampson. ^^ Excellent reviews of the subject are 

 those of Wohlisch,^^ Riegel,^^ Grossman,-'^ and Brinkhous." The reader is 

 particularly referred to the more recent comprehensive reviews of three 

 authorities in the field: Almquist,^^ Doisy ei al.,^'^ and Dam.^** Consider- 

 able information is to be obtained from the articles in Annual Reviews of 

 Biochemistry by Dam,'^ IMorton,^^ and Hickman. ^^ A complete review of 

 vitamin K up to 1945 is included in the monograph of Rosenberg.'* 



2. Occurrence of the K Vitamins 



The primary sources of the natural vitamin K compounds are plants and 

 microorganisms. It is believed that vitamin Ki occurs chiefly in green 

 leaves, while vitamin K2 is mainly a product of the metabolism of bacteria. 

 \'itamin Ki has been reported in the green leafy tissues of alfalfa^' and 

 spinach,^* in rice bran,^' and in cabbage, ''■^•'^•'® as well as in kale, cauliflower, 

 nettle, and chestnut." Dam and Glavind" also found that vitamin K oc- 

 curs in tomatoes, hempseed, and seaweed, while Almquist and Stok- 

 stad'* noted that it is a component of soybean oil. Oat shoots contain this 

 vitamin, and it is present in the cereals in limited amounts. ^*'"''^~*' 



21 S. B. Binklev, R. W. :\IcKee, S. A. Thaver, and E. A. Doisv, /. Biol. Chem., 133 

 721-729 (1940). 



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



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



2* E. Wohlisch, Ergeh. Physiol, biol. Chem. exptl. Pharmacol., 43, 174-370 (1940). 



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



=« A. M. Grossman, J. Pediat., 16, 239-253 (1940). 



2' K. RI. BrinUious, Medicine, 19, 329^16 (1940). 



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



29 E. A. Doisy, S. B. Binkley, and S. A. Thayer, Chem. Revs., 28, 4.11-b\7 (1941). 

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



" H. Dam, Ann. Rev. Biochem., 9, 353-382 (1940). 

 " R. A. Morton, Ann. Rev. Biochem., 11, 365-390 (1942). 

 " K. Hickman, Ann. Rev. Biochem., 12, 353-396 (1943). 



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

 1945. 



^ H. J. Almquist and E. L. R. Stokstad, Nature, 136, 31 (1935). 



36 W. F. Hoist and E. R. Halbrook, Science, 77, 354 (1933). 



37 H. Dam and J. Glavind, Biochem. J., 32, 485^87 (1938). 



'« H. J. Almquist and E. L. R. Stokstad, J. Nutrition, I4, 235-240 (1937). 

 33 H. Dam, Angew. Chetn., 50, 807-811 (1937). 



^» E. M. Nelson and C. D. Telle, Ann. Rev. Biochem., 8, 415-434 (1939). 

 " Members of Mayo Staff, Proc. Staff Meetings Mayo Clinic, 13, 65-80 (1938). 



