TRISOXIME – a Bulky Trisquaternary Reactivator of Acetylcholinesterase

Structure of acetylcholinesterase (AChE) reactivators influences their reactivation activity. Monoquaternary or bisquaternary reactivators are generally used for this purpose. In this work, there is discussed in vitro activity of trisquaternary AChE reactivator – Trisoxime (K388). Its reactivation activity is tested on the AChE inhibited by selected nerve agents – tabun, sarin, cyclosarin, soman, VX, Russian VX and diisopropyl fluorophosphates (DFP). As a result, only AChE inhibited by three nerve agents (VX, Russian VX and DFP) was satisfactorily reactivated at tested oxime concentrations (10-5 M and 10-3 M). This relatively poor reactivation potency was probably caused by the bulky spherical structure of tested oxime. Although results obtained in this study are not favorable, they are showing that the addition of one more quaternary ring to the reactivator´s molecule is not the right way to improve its reactivation potency.