Potency of novel oximes to reactivate sarin inhibited human cholinesterases.

Class of monoquaternary pyridinium oximes was in vitro tested as potential reactivators of acetylcholinesterase (AChE; EC 3.1.1.7) inhibited by nerve agent sarin. Human brain homogenate was used as an appropriate source of cholinesterases. Reactivation potency of novel oximes was compared with currently available reactivators - pralidoxime, obidoxime, and HI-6. According to the obtained results, only five reactivators were able to satisfactorily renew cholinesterase potency (pralidoxime, obidoxime, HI-6, 4-PAM, and K119). Unfortunately, none of the novel tested reactivators surpassed the reactivation potency of the currently most promising reactivator, HI-6. This study shows that monoquaternary reactivators are unable to reactivate nerve agent-inhibited AChE. Due to this, in future, only bisquaternary compounds derived from HI-6 or obidoxime should be designed as new potential cholinesterase reactivators.