Four new 4-substituted pyridinium-2-aldoxime methoiodides were prepared and their physico-chemical properties were estimated, including their pKa values. Compounds were tested as reactivators of acetylcholinesterase inhibited by isopropyl-methylphosphonofluoridate in vitro. Their acute toxicities were estimated in mice after i.m. administration. Results show that these compounds are less toxic than 2—pyridinium-aldoxime methiodide (2-PAM) alone, but only one compound was better reactivator than 2-PAM.

Keywords: Acetylcholinesterase; Organophosphates; Inhibition; Pyridinium-Aldoxlmes; Reactivators