The Physicochemical Properties of Some New Aminophosphonates

The hemolytic activity of some newly synthesized aminomethanephosphonic acid derivatives was studied. The compounds studied differed in their polarity and the hydrophobicity of the electronic substituents at their nitrogen and carbon atoms. It was found that acyclic aminophosphonates exhibited significantly stronger hemolytic properties than cyclic aminophosphonates. To cause the same level of hemolysis of pig erythrocytes, it was necessary to use about a tenfold higher concentration of cyclic aminophosphonates than acyclic ones. The hemolytic activities of the compounds were related to the possibilities of their incorporation into the lipid phase of erythrocyte membranes. Once incorporated, they changed the fluidity of those membranes; the changes were more pronounced in the case of cyclic aminophosphonates. Acyclic compounds were also found to exhibit a slight antioxidative activity, which may be a consequence of their stronger interaction with the membrane lipids. The results obtained in the experiments performed with the use of planar lipid membranes were similar to those obtained in the hemolytic studies, i.e., acyclic aminophosphonates interacted more effectively with those membranes. The general conclusion is that both stereochemistry and hydrophobicity are the factors that determine the efficiency of the interaction of the compounds studied with the model membranes used, and that most likely location of aminophosphonates is the lipid phase of the erythrocyte membrane. Another conclusion is that newly synthesized aminophosphonates may be used as potentially good pesticides.