STRUCTURE-ACTIVITY-RELATIONSHIPS FOR ORGANOTIN COMPOUNDS ON THE RED KILLIFISH ORYZIAS-LATIPES

The LC50 values of a series of 29 organotin compounds were determined for the red killifish (Oryzias latipes) according to an OECD test guideline. Their toxicities varied from 10(-1) to 10(-5) mmol dm-3 in five orders of magnitude. In this paper a quantitative structure-activity relationship (QSAR) study of these organotin compounds was carried out using physicochemical and topological parameters as independent variables. These parameters were found not to be good descriptors for estimating the LC50 values. However, when the term Index Value (IV), which is created as a new parameter and is defined by the number of phenyl or alkyl groups attached to the tin atom, was used, excellent regression equations to predict the toxicities of organotin compounds were obtained and a multiparametric relationship including IV, Information Index (I(D)W) and Mean Information Index (IBAR(D)W) showed the best correlation.