INHIBITION OF ACETYLCHOLINESTERASE AND ACUTE TOXICITY OF ORGANOPHOSPHOROUS COMPOUNDS TO FISH - A PRELIMINARY STRUCTURE-ACTIVITY ANALYSIS

The acute toxicity of twenty organophosphorous pesticides to guppies was determined and related to several physico-chemical properties by quantitative structure-activity relationships. Differences in LC50) data were analysed in terms of. (a) differences in potencies to inhibit acetylcholinesterase, (b) differences in rates of activation into the oxon analogues, (c) differences in alkylating potencies and (d) differences in biotransformation and bioconcentration. The analysis showed that it was not possible to obtain a complete model of the LC50 data in terms of the different processes. However, a QSAR analysis of the individual processes resulted in many interesting observations on the influence of the physico-chemical properties of the compounds on these processes.