Growth factor present in minute amounts in every living cell. Plays an indispensable role in numerous naturally occurring carboxylation reactions. Occurs mainly bound to proteins or polypeptides. The richest sources are liver, kidney, pancreas, yeast, and milk. The biotin content of cancerous tumors is higher than that of normal tissue. Biotin combines with the proteinaceous substance, avidin, in raw egg-white and becomes inactive. When on diets contg large amounts of raw egg-white the rat or chick develops characteristic skin lesions and growth is retarded; these symptoms can be prevented by feeding additional biotin. Isoln from egg yolk: K"ogl, T"onnis, Z. Physiol. Chem. 242, 43 (1936); from liver: Gy"orgy et al., J. Biol. Chem. 131, 745 (1939); du Vigneaud et al., ibid. 140, 643 (1941). Identity of biotin with vitamin H: du Vigneaud et al., Science 92, 62 (1940). Structure: du Vigneaud et al., J. Biol. Chem. 146, 475 (1942). First synthesis: Harris et al., J. Am. Chem. Soc. 67, 2096 (1945). Configuration: Traub, Nature 178, 649 (1956). Stereospecific total synthesis of the naturally occurring d-form: P. N. Confalone et al., J. Am. Chem. Soc. 97, 5936 (1975); eidem, J. Org. Chem. 42, 1630 (1977); T. Ogawa et al., Carbohydr. Res. 57, C31 (1977); F. G. M. Vogel et al., Ann. 1980, 1972; R. R. Schmidt, M. Maier, Synthesis 1982, 747. Synthesis of the dl-form: P. N. Confalone et al., Helv. Chim. Acta 59, 1005 (1976); M. Marx et al., J. Am. Chem. Soc. 99, 6794 (1977); A. Fliri, K. Hohenlohe-Oehringen, Ber. 113, 607 (1980); Ph. Rossy et al., Tetrahedron Lett. 22, 3493 (1981). Biosynthetic studies: R. J. Parry, M. G. Kunitani, J. Am. Chem. Soc. 98, 4024 (1976); R. J. Parry, M. V. Naidu, Tetrahedron Lett. 1980, 4783. Coordination properties: H. Siegel, Experientia 37, 789 (1981). Mechanism of action: M. J. Cravey, H. Kohn, J. Am. Chem. Soc. 102, 3928 (1980); D. L. Vesely, Science 216, 1329 (1982). Reviews: A. F. Wagner, K. Folkers, Vitamins and Coenzymes (Wiley, New York, 1964) pp 138-159; Harris in The Vitamins vol. II, W. H. Sebrell, R. S. Harris, Eds. (Academic Press, New York, 2nd ed., 1968) pp 261-359; D. B. McCormick, Nutr. Rev. 33, 97-102 (1975). Review of assay methods: P. Gy"orgy, The Vitamins vol. VII, P. Gyorgy, W. N. Pearson, Eds. (1967) pp 303-313.
Vitamin (enzyme cofactor).
Vitamin/Vitamin Source