Preliminary estimation of physiological activity of 9-amine-9-fluorenephosphonic acid derivatives

The physiological activity of twenty one 9-amine-9-fluorenephosphonic acid derivatives was tested. The compounds were synthesized by the Wrocław Technical University. Spirodela oligorrhiza was used as the test plant. There was tested the inhibiting influence of these compounds on the growth of Spirodela and synergism with the herbicide "mecoprop". Ethyl esters substituted at the nitrogen atom with buthyl and heptyl group appeared to be most active. Their concentration of 0.5-1.5 × 10-5 M inhibited the growth of Spirodela by 50%. Most of the 9-amine-9-fluorenephosphonic acid derivatives tested with different substitutes showed a strong synergism with the herbicide "mecoprop". An addition of these compounds to sublethal solution of the herbicide killed Spirodela within 10-20 houres