Abstract

JARAMILLO C, BEATRIZ EUGENIA; MARTELO E, IRINA  and  DUARTE R, EDISSON. ACUTE TOXICITY OF ORGANOPHOSPHORUS PESTICIDES AND ANALYSIS OF QUANTITATIVE STRUCTURE - ACTIVITY RELATIONSHIP (QSAR). Rev.Bio.Agro [online]. 2013, vol.11, n.2, pp.76-84. ISSN 1692-3561.

Organophosphate pesticides are phosphoric acid esters (OPs) often used as insecticides and acaricides. They are a very important group of environmental pollutants used in intensive agriculture for protection against pests, produce disturbances in biochemical reactions necessary for normal metabolism, exhibit a wide range of mammalian toxicity and act on the central nervous system as inhibitors of acetylcholinesterase. In this study, the median lethal concentration (LC50) of seventeen organophosphorus compounds against Artemiafranciscana was evaluated. The most toxic compound was Fenthion with LC50 of 6,26 µg/mL at 24 h of exposure and 0,11 µg/mL at 48 h; and those with less toxicity were Chlorpyrifos and Malathion with LC50 values greater than 100 µg/mL. Quantitative structure activity relationships (QSAR) models were developed to predict toxicity of OPs by correlating LC50 values with molecular descriptors by using computational methods and statistical tools. The molecular descriptors, which showed the best relationship, were Dipole moment (µ) and the partition coefficient octanol/water (LogP). They showed a significant linear correlation with R2 of 0,8107 and 0,8546 for 24 h and 48 h of exposure against A. franciscana respectively.

Keywords : Artemia franciscana; Median lethal concentration; Molecular descriptors.

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