OCCURRENCE OF VITAMINS K 755 



cereals. ^^•'^•^**'^^''*'' Dam, CUaviud, and Gabrielson^-^ re\'iewed the general 

 subject of the occurrence of vitamin K in plants. 1 hey concluded that the 

 parts of the plant from which chlorophyll is al^sent are largely devoid of 

 \'itamin K. However, yellow-spotted leaf areas \\ere found to contain as 

 much vitamin K as did the green areas. A^ariations m the mtensity of green 

 in the leaA'es of different varieties of plants could not be correlated with a 

 similar difference in vitamin K content. The natural changes in chloro- 

 phyll which occiu" on the death of the leaves in the autumn do not bring 

 about a corresponding destruction of the vitamin K. Finally, no relation- 

 ship has been established between the carotene or xanthophyll content and 

 the amount of A'itamin K.^^ Vitamin K present in the pressjuice of spin- 

 ach leaves was stable after standing overnight. Most of the vitamin was 

 found in the chloroplasts."*^ 



(^) Occurrence in Microorganisms 



According to Almquist, Pentler, and Mecchi,^^ most bacteria contain 

 ^'itamin Ko. Antihemorrhagic activity was shown to develop in foodstuffs 

 duruig bacterial spoilage," and also to be present in the feces of chicks which 

 (lid not receive vitamin K in their diet."**^ In a further study of this problem, 

 Almcjuist^^ cultivated \'arious pure strains of bacteria on a vitamin K-free 

 medium, and determined the vitamin K activity of the bacterial cultures. 

 The \'itamin K activities (expressed as 2-methyl-l,4-naphthoquinone units 

 per g.) were as follows:''^ Bacilhcs suhtilis, 190; Bacillus mycoides, 155; 

 Bacillus cereus, 115; Sarcina lutea, 100; Proteus vulgaris {Bacterium pro- 

 teus), 75; Micrococcus pyogenes A^ar. aureus, 60; Mycobacterium tuberculo- 

 sis, 55; Shigella flexneri, 30; A er abactor aerogenes, 20: Serratia marcescens 

 {Erythrobacillus prodigiosus), 20; Salmonella typhosa, 15; and Escherichia 

 coli, 15. 



Intestinal l)acteria, in general, can readily synthesize vitamin K. For 

 this reason the vitamin appears in feces of the chick'*"' and of human subjects. 

 It is also present in the rumen of the cow, even when the animal is on a 

 ^-itamin K-deficient diet.*^ In this case the vitamin is synthesized by the 

 microorganisms in the rumen. Molds, yeasts, and fungi contain practically 

 no vitamin Ki or K2. 



" H. Dam, Angew. Chem., 50, 807-811 (1937). 



** E. M. Nelson and C. D. Tolle, Ann. Rev. Biochem., 8, 415-434 (1939). 

 « H. Dam, J. Glavind, and E. K. Gahrielson, Acta Ph/siol. Scand., 13, 9-19 (1947). 

 *« H. Dam, E. Hjorth, and I. Kruse, Phiisiologia Plantarum, 1, 379-381 (1948). 

 " J. Almquist, C. F. Pentler, and E. Mecchi, Proc. Soc. Exptl. Biol. Med., 38, 336-338 

 (1938). 



« H. J. AlnKiuist and E. L. R. Stokstad, J. Nutrition, 12, 329-335 (1936). 

 « L. W. McElroy and H. Goss, /. Nidrilion, 20, 527-540 (1940). 



