PREPARATION OF CORTICAL HORMONE 247 



Several workers have reported physiological experiments, the 

 results of which they attributed to the cortical hormone because 

 the effects were not elicited after heating the extract to boiling. 

 As a matter of fact, the hormone is not readily destroyed by 

 heat. At a pH of 6.7 one can maintain the extract at its 

 boiling point for ten minutes without appreciable destruction 

 of the hormone. Heating strongly acid or alkaline solutions of 

 the hormone, on the other hand, leads to its rapid destruction. 

 In fact, if kept in an alkaline aqueous solution in the refrigera- 

 tor, the hormone will be found to become inactivated. Appar- 

 ently it undergoes a molecular rearrangement or other spon- 

 taneous chemical change in the presence of alkali. This 

 destruction must be guarded against by keeping all aqueous 

 solutions of the hormone at a pH of about 6.8 to 7.0. 



One of the most striking chemical properties of the purified 

 extract of the hormone is the ease with which it reduces a 

 number of the common reagents, — permanganate, silver ni- 

 trate, phosphomolybdic acid, etc. If this property proves to be 

 inherent in the hormone, and not a result of contaminating 

 agents, it will offer a chemical method for estimating the hor- 

 mone. The fact that extracts free of ascorbic acid, uric acid, 

 and epinephrine still reduce the Folin-Denis reagent makes it 

 impossible to use this colorimetric method for the determina- 

 tion of the epinephrine content of cortical extracts. Extracts 

 in which epinephrine may be shown to be absent by the usual 

 biological tests, still give the blue coloration when tested by 

 this method. 



Wintersteiner and his collaborators 512 have recently described 

 a procedure for concentrating the cortical hormone. Their 

 final product is a yellow syrup containing the hormone, which 

 they believe to be an «-/3-unsaturated ketone. The evidence 

 adduced to substantiate this view is not, however, conclusive. 



