334 INOSITOLS 



D. DISTRIBUTION 



1. meso-lNOSiTOL 



meso-Inositol, discovered by J. Scherer^^ in 1850, appears to be an almost 

 ubiquitous and possibly essential cellular component. A survey of its oc- 

 currence in plant and animal tissues has been given by Fleury and Balatre.^ 

 The extent to which it is present in all microorganisms cannot yet be 

 stated. It is doubtless an important constituent of the Hpids and other 

 fractions of acid-fast bacteria from which it has been isolated in quan- 

 tity .^^-^e 



When meso-inositol is stated to occur in almost all types of cell, this 

 must not be taken to mean that it can always be isolated from them without 

 more or less extensive degradative action. There are obviously many types 

 of derivatives in which inositol is able, and often has been shown, to exist, 

 such as ethers, esters, lipids, and therefore also in lipoproteins, phospho- 

 proteins, etc. It has frequently been found in the free form; but this may 

 often have been due to enzymatic liberation taking place in the course of 

 the preparation or the assay. 



Among the naturally occurring derivatives of meso-inositol, the following 

 may be mentioned. Bornesitol, a dextrorotatory monomethyl ether f- ^^ 

 sequoitol, an optically inactive monomethyl ether;^^' »" and dambonitol, an 

 inactive dimethyl ether.^^-^^ One of the most widely distributed forms of 

 meso-inositol is phytin, the hexaphosphoric acid ester. The various phos- 

 phates of inositol have been reviewed recently by Courtois.^^ The occur- 

 rence of meso-inositol as a component of an entire series of lipids is of 

 great interest. It was first discovered, in this combination, in lipid prepara- 

 tions from tubercle bacilli and related acid-fast microorganisms,^^- ^s and 

 later it was shown to occur in soybean phosphatides^^- *^ and in brain 

 phosphatides.^^ The structure of the soybean inositide, for which the name 



2* J. Scherer, Ann. Chem. Justus Liebigs 73, 322 (1850). 



" R. J. Anderson, /. Am. Chem. Soc. 52, 1607 (1930). 



26 E. Chargaff and R. J. Anderson, Hoppe-Seyler's Z. physiol. Chem. 191, 172 (1930). 



2' A. Girard, Compt. rend. 73, 426 (1871). 



28 E. R. Flint and B. Tollens, Ann. Chem. Justus Liebigs 272, 288 (1893). 



29 E. C. Sherrard and E. F. Kurth, /. Am. Chem. Soc. 51, 3139 (1929). 



30 N. V. Riggs, /. Chem. Soc. 1949, 3199. 



31 A. Girard, Compt. rend. 67, 820 (1868). 



32 C. O. Weber, Ber. deut. chem. Ges. 36, 3108 (1903). 



33 A. W. K. De Jong, Rec. trav. chim. 27, 257 (1908). 



34 J. E. Courtois, Bull. soc. chim. biol. 33, 1075 (1951). 



36 E. Klenk and R. Sakai, Hoppe-Seyler's Z. physiol. Chem. 258, 33 (1939). 



36 D. W. Woolley, /. Biol. Chem. 147, 581 (1943). 



37 J. Folch and D. W. Woolley, /. Biol. Chem. 142, 963 (1942). 



