REACTIVATORS OF ACETYLCHOLINESTERASE INHIBITED BY ORGANOPHOSPHORUS COMPOUNDS - IMIDAZOLE DERIVATIVES .2.

A series of mono and bis imidazolium compounds containing benzyl, phenyl and 4-metoxyphenyl substituents in position 3 of imidazole ring were prepared and characterized by elemental analysis, IR and H-1 NMR spectroscopy. Compounds in which one imidazole ring was replaced by 2- and 4-hydroxyiminomethylpyridine were also prepared. The inhibitory power of the oximes (IC-50), percentage of reactivation after inhibition by sarin, VX, tabun and soman have been determined for human erythrocyte AChE. IC-50 values varied from 0.315 to 560-mu-mol l-1. With 20-mu-mol l-1 percentage of reactivation was 2.87 - 96.3% for sarin, 2.7 - 72.8% for VX, 0 - 44.1% for tabun and 0 - 10.1% for soman inhibited AChE. Benzylimidazolium oximes (30-mu-mol kg-1) given to rats together with atropine (10 mg kg-1) provided good protection against VX (5.7 to 24.0 LD-50), tabun (3.6 to 4.9 LD-50) and sarin (1.4 to 5.9 LD-50) while being little effective in soman poisoning (1.3 to 1.8 LD-50).