III. INDUSTRIAL PREPARATION 339 



III. Industrial Preparation 



E. R. WEIDLEIN, JR. 



In the absence of a practical chemical synthesis for inositol, the com- 

 pound has been obtained industrially by isolation of the natural vitamin 

 from plant sources. 



A. PRESENCE IN PLANTS 



Inositol is found widely distributed in many different types of plants. 

 It is most frequently encountered in combination with phosphoric acid, 

 although free inositol and monomethyl and dimethyl ethers of inositol 

 have also been isolated from some plant species. Phospholipids which con- 

 tain inositol, rather than glycerol, as the polyalcohol are an important 

 class of phosphoric acid derivatives in plants as well as in animals. How- 

 ever, the most common form for the occurrence of inositol in plants is as a 

 hexaphosphoric acid ester called phytic acid, a compound which is capable 

 of forming salts with potassium, calcium, magnesium, iron, manganese, 

 and other metals of importance in plant nutrition. 



Phytic acid and its salts appear to be heavily concentrated in seeds and 

 cereal grains, in which phytate may account for as much as 86 % of the 

 total phosphorus present.^ In some instances the phytate has also been 

 shown to exist in combination as a protein complex.^ Little is known of 

 the functions of phytates in plant metabolism, but they have been pre- 

 sumed to act as stores of phosphoric acid which may be utilized by the 

 plant during sprouting. This opinion is supported by the fact that the 

 concentration of free inositol has been found to increase in several different 

 types of seeds during germination.^ It also has been recognized that phytates 

 may function as carriers for trace metals needed to insure normal plant 

 growth.^ 



Approximately 80% of the phosphorus in corn exists as phytate, corn 

 having been reported to have a content of phytic acid phosphorus which 

 varies from 0.199 to 0.270 %, compared with a variation in total phosphorus 

 of 0.248 to 0.330 % on the same basis. ^ Among the other plants in which 

 phytic acid has been found are wheat, rye, oats, peas, beans, barley, rice, 

 cottonseed, flaxseed, soybeans, and peanuts. 



In extracting the phytate from plant materials, investigators have most 



1 H. Mollgaard, K. Lorenzen, I. G. Hansen, and P. E. Christensen, Biochem. J. 

 (London) 40, 589 (1946). 



2 T. D. Fontaine, W. A. Pons, Jr., and G. W. Irving, Jr., J. Biol. Chem. 164, 487 

 (1946). 



3 V. H. Cheldelin and R. L. Lane, Proc. Soc. Exptl. Biol. Med. 54, 53 (1943). 

 * E. R. Weidlein, Jr., Mellon Inst. Bibliographic Ser. Bull. 6 (1951). 



