342 INOSITOLS 



decolorized with bone black or activated carbon, filtered to remove carbon, 

 and concentrated by vacuum-pan evaporation. 



Crystallization of inositol from the mother liquor is generally accom- 

 plished by gradual cooling to as low a temperature as practical with con- 

 tinuous, moderate agitation. Crystals are separated from the mother 

 liquor by centrifugation and are then further washed and dried. Several 

 crops of crystals may be recovered by concentration of the mother liquor 

 and a repetition of the crystallization process. 



The inositol obtained in this manner is an anhydrous, colorless, crystal- 

 line material having a melting point of approximately 225°, which is char- 

 acteristic of the pure myo isomer. 



IV. Biochemical Systems 



HENRY A. LARDY 



The widespread occurrence and relatively great abundance of myo- 

 inositol make this compound unique among the vitamins in that it may 

 act both catalytically, like the other vitamins, and as an energy-yielding 

 foodstuff or metabolite. These two aspects of the biochemical systems in 

 which mi/o-inositol participates will therefore be discussed separately. 



A. BIOCATALYTIC FUNCTIONS OF MFO-INOSITOL 



?n?/o-Inositol is an essential nutrient for several strains of yeast, ^"^ for 

 fungi,^' * for a mutant of Neurospora crassa,^ and for mice,'^- ^ rats,^ cotton 

 rats,^"' " hamsters, ^2 and chicks^^ under certain deitary regimens. In spite 



1 E. V. Eastcott, J. Physiol. Chem. 32, 1094 (1928). 



2 R. J. Williams, R. E. Eakin, and E. E. Snell, /. Am. Chem. Soc. 62, 1204 (1940). 



3 L. Atkin, A. S. Schultz, W. L. Williams, and C. N. Frey, Ind. Eng. Chem. Anal. Ed. 

 15, 141 (1943). 



* F. Kogl and N. Fries, Hoppe-Seijler's Z. physiol. Chem. 249, 93 (1937). 

 6 W. J. Robbins, J. E. Mackinnon, and R. Ma, Bull. Torrey Botan. Club 69, 509 

 (1942). 



6 G. W. Beadle, /. Biol. Chem. 156, 683 (1944). 



7 D. W. Woolley, J. Biol. Chem. 136, 113 (1940). 



8 D. W. Woolley, J. Biol. Chem. 139, 20 (1941). 



9 T. J. Cunha, S. Kirkwood, P. H. Phillips, and G. Bohstedt, Proc. Soc. Exptl. Biol. 

 Med. 54, 236 (1943). 



10 J. M. Mclntire, B. S. Schweigert, and C. A. Elvehjem, J. Nutrition 27, 1 (1944). 

 " B. S. Schweigert, Vitamins and Hormones 6, 55 (1948). 



12 J. M. Cooperman, H. A. Waisman, and C. A. Elvehjem, Proc. Soc. Exptl. Biol. 

 Med. 52, 250 (1943). 



13 D. M. Hegsted, G. M. Briggs Jr., R. C. Mills, C. A. Elvehjem, and E. B. Hart, 

 Proc. Soc. Exptl. Biol. Med. 47, 376 (1941). 



