CYC LOSES 95 



employment of lubricants will diminish the necessary consumption of 

 gasoline in an automobile-engine. Their influence upon the nutrition 

 of animals is indirect, however, and not direct, and the hydro-aromatic 

 derivatives must for this reason be classified as Accessory Foodstuffs 

 or foodstuffs which are primarily utilized for other purposes than the 

 production of work and heat, or the building up of the structural 

 elements of tissues. 



THE CYCLOSES. 



The hydro-aromatic compounds which lie nearest to the carbo- 

 hydrates in their physical properties and physiological behavior are 

 the Cy closes, or hexa-hydroxy-benzoles, which are represented by the 

 formula : 



CHOH 



HOHC CHOH 



HOHC CHOH 



\/ 



CHOH 



A number of isomeric compounds are represented by this formula, 

 differing from one another in the arrangement of hydrogen and hydroxyl 

 groups about the carbons. The form which occurs in animal tissues is 

 optically inactive, the levo- and dextrorotatory carbons being balanced 

 and equalized within the molecule. This cyclose is designated Inosite. 

 In vegetable tissues it is found widely distributed, occasionally in the 

 form of ester-like compounds (dambonite, bornesite), but chiefly in 

 the form of the hexaphosphate, the calcium-magnesium salt of which 

 is known commercially as Phytin. This substance occurs particularly 

 abundantly in seeds and grains, the husks of which also contain a fer- 

 ment, Phytase, which is capable of splitting the compound, in aqueous 

 solution, into inosite and phosphoric acid, a hydrolysis which other- 

 wise can only be accomplished completely by exposing the substance 

 in acid solution to a temperature very considerably above that of boil- 

 ing water. Intermediate steps in the hydrolysis of inosite hexaphos- 

 phate by phytase are the tri- and mono-phosphates which do not, 

 however, occur preformed in the tissues of grains. 



In mammals i-inosite is found in small amounts in muscular tissue, 

 from which it was first obtained and recognized as a distinct chemical 

 entity. It is also found in combination with a complex fatty substance, 

 containing phosphorus and nitrogen, in the tissue of the anterior lobe 

 of the pituitary body. This compound, to which the name Tethelin 

 has been applied, is probably the physiologically active principle of the 

 gland. On somewhat prolonged hydrolysis by alkalies and acids the 

 substance breaks up and yields free i-inosite. 



Inosite is readilv soluble in water and alcohol and is obtained in the 



