Modelling of the association mechanism of a series of rodenticide molecules with lipid membrane investigated by computational chemistry and biochromatography

The increase of pest rodents population in urban and rural areas is tackled by dissemination of baits poisoned with anticoagulant compounds. In order to modelize the cell membrane transport of these rodenticides, which have toxic effect on human keratynocytes and break the vitamin K cycle, a new general model based on the perturbation method was developed to describe the association process between these rodenticide and an immobilized artificial membrane (IAM). The thermodynamic functions of the rodenticide transfer from the bulk solvent to the IAM surface were also determined. The variation plots of the solute transfer data versus the salt concentration (x) in the bulk solvent allow to demonstrate hat the rolenticides-IAM surface association mechanism was governed by both the hydrophobic effect and the van der Waals interactions/hydrogen bonds between the rodenticide polar groups with the polar headgroups of phospholipid monolayers (polar retention effect). This result was also corroborated by a comparison of the number of water molecules surrounded the rodenticide in the medium (obtained by computational chemistry) and the number of water molecule release at the IAM-rodenticide interface (obtained thanks to the Tanford's equation). (c) 2005 Elsevier B.V. All rights reserved.