Monooxime Bispyridinium Reactivators Bearing Xylene Linker Synthesis and In Vitro Evaluation on Model of Organophosphate-Inhibited Acetylcholinesterase.

Nine novel mono-oxime reactivators bearing xylene linker were synthesized in an effort to improve previously prepared xylene bisoximes and monocarbamoyl-monooximes. The novel compounds were tested in vitro on the model of tabun-, paraoxon-, methylparaoxon- and DFP-inhibited human erythrocyte AChE. Their reactivation ability was compared to pralidoxime, asoxime, obidoxime and two previously prepared xylene linked bisoximes (K107, K108). All compounds showed minimal reactivation of tabun-inhibited AChE at selected concentration scale. This finding was explained by molecular modelling study. Bisoximes obidoxime and K108 resulted as the best reactivators for paraoxon-, methylparaoxon-and DFP-inhibited AChE. The loss of non-oxime moiety lead to the loss of reactivation ability within the novel compounds. Though the novel reactivators did not exceed previously known compounds, they confirmed former SAR findings for xylene-linked AChE reactivators.