Toxicological Investigation of New Synthesized Reagents - Functionalized Phosphonates with Photocontrolled Biological Activity

The toxic properties of newly synthesized vinylphosphonates, namely, diene compounds with ethyl and isopropyl substituents in the phosphonate group were examined in this study. Previous studies have revealed laser-induced cistrans isomerization of these compounds. In addition, the high biological activity of vinylphosphonates and its significant dependence on photoirradiation have been found. The proven possibility of controlling the biological activity of synthesized phosphonates under laser irradiation opens prospects for applying them in photopharmacology and producing drugs with the capability of remote and precise control over the area and duration of their therapeutic effect. Due to the promising application of synthesized phosphonates in photopharmacology, the relevant task for the first stages of research was ascertaining the toxic effects of these synthesized compounds. The toxicity of the substances, including daphnia, ciliates, and unicellular green algae, was tested using a bioassay system. Considering the insolubility of the synthesized phosphonates in water, experiments were carried out after the preliminary dissolution of the phosphonates in dichloromethane at a harmless dichloromethane concentration in water for the selected test organisms. Major Findings: Based on the results obtained, the toxicological parameters of phosphonates were calculated including lethal concentration LC50 (0.2×10-5 M/L) and effective concentration EC50 (3.3 × 10-5 M/L), as well as no observed effect concentration NOEC (0.9 × 10-6 M/L), which do not cause a statistically significant toxic effect. Daphnia were the most sensitive to synthesized phosphonates.