470 



Colchicine 



K-be}2zoyI-coIchicinic anJiydride (XII) , have been tested on tumors.'^^ 

 None has shown an activity comparable to colchicine, and the reader 

 should refer to the papers of the National C;anccr Institute group for 

 detailed data on this subject.^- i- ^^' «^' ^'^ 



Although colchicine derivatives have been tested on few materials, 

 the main pinpose of the work having been a search for substances of 



NH.C0CH5 



CH'jO 



= 



NHo 



(X) 



CH3O 



CH3O 



NH.COCH3 



CH3O 



CH3O 



CH3O 



NH-CO 



c = o 



o = c- 



-0 



%/ OH 



(XI) N-Acetylcolchinol 



(XII) 



interest in cancer chemotheraj))', the following conclusions can be 

 drawn for the papers published: 



1. The /^ocolchicine derivatives, and /^colchicine itself, are con- 

 siderably less active. It appears important that the esterified side- 

 chains of rings B and C are at a proper distance one from another. 



2. At least one methoxy group appears indispensable in ring A. 



.H. The amino group of ring B does not need to be esterided, though 



this increases the activity. 

 4. Ring C must be seven-membered, and the hydroxyl grouj) esteri- 

 fied, or better, replaced by an amino group itself esterified (colchi- 

 camide derivatives) . 



These facts help to reveal which are the active groups of the 

 colchicine molecule. However, they are yet of no help in explain- 

 ing how these react with the spindle. Results obtained with spindle 



