Synthesis of some new cyclic aminophosphonates and their physiological activities

The synthesis of 19 newly synthesized cyclic aminophosphonic acid derivativ es was described and their biological activity studied. It was found, as in the case of the previously described series of acyclic analogues, that the phytotoxicity of the compounds, tested on aquatic plant Spirodela oligorrh iza depended mainly on their hydrophobic parameters. The most pronounced ph ytotoxicity, the measure of which was concentration of aminophosphonates ca using 50% inhibition of plant growth (EC50), exhibited compounds with not t oo long hydrocarbon substituent on the nitrogen atom (8-10 carbon atoms) an d branched propyl groups on the phosphorus atom. The test had preliminary c haracter and permitted to eliminate the less promising compounds for furthe r studies.