VIII. OCCURRENCE 363 



VIII. Occurrence 



ARTHUR H. LIVERMORE 



The naturally occurring inositol isomers are found in many plants and 

 in some animal tissues.^ ■ ^ The two optically active isomers have been 

 found chiefly in various trees. D-Inositol occurs as the monomethyl ether, 

 pinitol, and L-inositol as the monomethyl ether, quebrachitol. The other 

 naturally occurring isomer of inositol is scyllitol. Scyllitol has been found 

 both in plant products and in elasmobranch fishes. It has also recently been 

 found, together with m^/o-inositol, in urine and in blood. ^ In addition to 

 these compounds, other related substances have also been found in plant 

 products. Among these are the desoxyinositols, C-methylinositols, inososes 

 (pentahydroxycyclohexanones), and also the tri- and tetrahydroxy hexane 

 carboxylic acids (quinic acid and shikimic acid).^'^ 



A. IN FOODS 



Since m^/o-inositol is the only inositol isomer having significant vitamin 

 activity, only this isomer has been determined extensively in food products. 

 Most of the determinations of the inositol content of foods have been made 

 by microbiological methods. Since the microorganisms which are used for 

 these determinations use m?/o-inositol specifically, the results of these 

 determinations undoubtedly give the m?/o-inositol content of the food 

 products. The same cannot be said of chemical methods since these pro- 

 cedures (e.g., periodate oxidation) will not distinguish between the various 

 isomers, and it is possible that scyllitol and d- or L-inositol might in some 

 cases be determined as well as myo-inositol. 



Some of the results of analyses of various food products for inositol 

 have been collected in Table VII. This is by no means an exhaustive list 

 of the food products studied. The original literature cited should be con- 

 sulted for other foods. 



B. NATURAL ANTIVITAMINS OF INOSITOL 



The structure of the streptamine moiety of streptomycin is very similar 

 to the structure of inositol. Streptamine is a diaminotetrahydroxycyclo- 



1 H. G. Fletcher, Jr., Advances in Carbohydrate Cheni. 3, 45 (1948). 



2 W. W. Pigman and R. M. Goepp, Jr., Chemistry of the Carbohydrates, p. 266, 

 Academic Press, New York, 1948. 



» P. Fleury, Bull. soc. chim. biol. 33, 1061 (1951). 



* V. H. Cheldelin and R. J. Williams, Univ. Texas Publ. 4237, 105, (1942). 



