STUDIES ON THE QUANTITATIVE STRUCTUREACTIVITY RELATIONSHIP OF THE SCHISTOSOMICIDAL SUBSTANCES——BROMOACETIC ESTERS

The quantum mechanical indices of 26 antischistosomal bromoacetic esters were computed by the HMO method. The lgP value of BrCH₂CO₂ NHCOCH₃ was determined, π_BrCH2CO2, was calculated, and the lgP values of these bromoacetic esters were thus obtained. Progressive regression analysis indicated that lg²P, lgP and E_LEMO were related to the biological activities, which were supported by the mechanism of physiological action of halogenoacetic acid derivatives reported in the literature. The optimum lgP value calculated (1.09) was within the range of lgP values of the schistosomicides in the literature. The Hansch equation obtained predicted that BrCH₂CO₂CH=N may have somewhat higher biological activity, and the value calculated was in fair accordance with the value determined.