SECTIONAL TRANSACTIONS.— B. 



409 



there is as yet no International Standard Unit of biological activity. It is 

 generally agreed that certain amorphous adrenal cortex concentrates show 

 greater biological activity than the pure corticosterone. It is possible 

 therefore that there is in the whole extract an unidentified substance of greater 

 activity. It is certainj however, that not a single life-maintaining hormone 

 is produced by the adrenal cortex but a group of related substances some 

 of which possess biological activity. 



Since it is not yet possible to make a complete synthesis of the sterol 

 nucleus, only partial syntheses of compounds related to the adrenal cortical 

 hormones have been achieved. The following scheme shows (steps V to 

 XI) in outline a synthesis of deoxy-corticosterone (XI) from 3-hydroxy- 

 aetio-cholenic acid (V) which can be obtained by degradation of chol- 

 esterol or stigmasterol. 



"XL 



HO 



AcO/ 



COOH 



CO-Cl 



CH,N, 



AcO/\/\/ 



VI 



CO-CHN2 



KOH 



HO 



CO-CHN, 



VII 



VIII 



CH.COOH 



CO-CH^OAc 

 Brji 



HO^ 



CrOg 

 Zn 



O^/ 



X 



-CO-CH»OAc 



CO-CH,OH 



Deoxy-corticosterone 



Deoxy-corticosterone (XI) differs from natural corticosterone (I) in not 

 possessing a hydroxy-group in the 11 -position. Biological tests have 

 mostly been carried out with the acetate (X) of deoxy-corticosterone and 

 the results indicate that the activity of this compound is greater than that 

 of natural corticosterone. The acetate eliminates the pathological symptoms 

 resulting from adrenalectomy in the same manner as the natural hormone. 

 It seems probable that deoxy-corticosterone is the simplest compound 

 showing full ' cortin-activity.' Hydrogenation of the double bond prac- 

 tically eliminates the biological activity. Elimination of the hydroxy-group 



