128 



BACTERIOLOGICAL CHEMISTRY 



Many compounds, ])a8ecl on the structure <jf the 

 effective drug, emetine, have been synthesised and 

 tested for treatment of amoebic dysentery, but none, so 

 far, has been found to exceed emetine in therapeutic 

 value, although some are more toxic to Entamceba 

 histolytica when tested in vitro. 



Similar search for antimalarial drugs primarily based 

 on the structure of quinine, 



CHOH— CH— N CH, 



CH2— CH— CH.CH ^CHg 



N 



has led to the production of plasmoquin, 



CH3.CH. (CH2)3.N : {C,H,), 



CH,0 



and atebrine, or mepacrine, 



CH3.CH.(CHj)3.N : (C,H5)2 



I 

 NH 



I 



C2H5O 



CI 



N 



which are of considerable value. A further extension of 

 this search in recent years has led to the discovery of 

 paludrine, Ni-p-chlorophenyl-N5-mpropyl-biguanidine: — 



CH, 



/ 

 >NH.C— NH— C— NH.CH 



II II \ 



NH NH CHj 



