A comparison of the therapeutic and reactivating efficacy of newly developed bispyridinium compounds (K206, K269) with currently available oximes against tabun in rats and mice

The benefit of combinations of oximes for the ability of antidotal treatment to counteract sarin-induced brain damage in rats

Background

The aim of our study was to compare the ability of two combinations of oximes (HI-6 + trimedoxime and HI-6 + K203) with atropine to counteract acute sarin-induced brain damage with the efficacy of antidotal treatment involving single oxime (HI-6) and atropin using in vivo methods.

Methods

Brain damage and neuroprotective effects of antidotal treatment were evaluated in rats poisoned with sarin at a sublethal dose (108 μg/kg i.m.; 90% LD₅₀) using histopathological, Fluoro-Jade B and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis 24 h after sarin administration.

Results

Both combinations of oximes reduce the number of rats that died before the end of experiment compared to non-treated sarin poisoning and sarin poisoning treated with HI-6 and atropine. In the case of treatment of sarin poisoning with HI-6 in combination with K203, all rats survived till the end of experiment. HI-6 with atropine was able to reduce sarin-induced brain damage, however, both combinations were slightly more effective.

Conclusions

The oxime HI-6 in combination with K203 and atropine seems to be the most effective. Thus, both tested oxime combinations bring a small benefit in elimination of acute sarin-induced brain damage compared to single oxime antidotal therapy.

A study on quantum chemical calculations of 3-, 4-nitrobenzaldehyde oximes

The molecular geometry, vibrational frequencies, 1H and 13C NMR chemical shifts, UV-vis spectra, HOMO-LUMO analyses, molecular electrostatic potentials (MEPs), , thermodynamic properties and atomic charges of 3- and 4-Nitrobenzaldehyde oxime (C7H6N2O3) molecules have been investigated by using Hartree-Fock (HF) and density functional theory (DFT/B3LYP) methods with the 6-311++G(d, p) basis set. The calculated optimized geometric parameters (bond lengths and bond angles), the vibrational frequencies calculated and 13C and 1H NMR chemical shifts values for the mentioned compounds are in a very good agreement with the experimental data. Furthermore, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) have been simulated and the transition states, energy band gaps and molecular electrostatic potential (MEP) maps for each oxime compound have been determined. Additionally, we also report the infrared intensities and Raman activities for the compounds under study.

Oxime K027: novel low-toxic candidate for the universal reactivator of nerve agent- and pesticide-inhibited acetylcholinesterase

Oxime K027 is a low-toxic bisquaternary compound originally developed as a reactivator of acetylcholinesterase (AChE) inhibited by nerve agents. The reactivation potency of K027 has been tested as a potential reactivator of AChE inhibited by tabun, sarin, cyclosarin, soman, VX, Russian VX, paraoxon, methylchlorpyrifos, and DDVP. The results show that oxime K027 reactivated AChE inhibited by almost all tested inhibitors to more than 10%, which is believed to be enough for saving the lives of intoxicated organisms. In the case of cyclosarin- and soman-inhibited AChE, oxime K027 did not reach sufficient reactivation potency.