Zlatko Binenfeld

Antidotal efficacy of quinuclidinium oximes against soman poisoning

The efficiency of newly synthesized oxime derivatives of quinuclidinium were tested in vitro on soman inhibited acetylcholinesterase (AChE) of human erythrocytes and in vivo using soman poisoned mice. For this purpose, the inhibitory power of oximes (IC50), acute toxicity (LD50) as well as reactivating and protective capacities with respect to soman-inhibited AChE were determined for each of the oximes. All oximes tested were ineffective in vitro but protected mice very efficiently (BM-1 protects against 4LD50 of soman). The results indicate that the in vivo effectiveness of quinuclidinium oximes against soman poisoning may not be related to reactivation or protection of AChE but rather to some other mechanism of the cholinergic system.

Reactivators of organophosphate-inhibited cholinesterase

Two isomeric cyclopentylcarbonyl and two cycloheptylcarbonyl derivatives of 2-hydroxyiminomethyl-1-[3-(1-pyridinio-2-oxapropyl] pyridinium diiodide and 4-hydroxyiminomethyl-1-[3-(1-pyridinio-2-oxapropyl] pyridinium diiodide were prepared and characterized by spectroscopic methods. The inhibitory power (I50) of the investigated oximes was determined using purified bovine erythrocyte AChE and human erythrocyte AChE. Percentage of reactivation after 30 min was estimated after inhibition of human erythrocyte AChE by sarin, VX, tabun, soman, and paraoxon. The in vitro protective indices (p.i. and P50) against inhibition by soman have been calculated using bovine erythrocyte AChE for p.i. and human erythrocyte AChE for P50. Their I50 for human erythrocyte AChE varied from 1.4–9.8 (10−4 mol · dm−3) and for bovine erythrocyte AChE in the range of 1.1–17 (10−5 mol · dm−3). With 2 × 10−5 mol · dm−3 oximes the percent of reactivation was: 0–17% for paraoxon-inhibited AChE, 9–49% for sarin-inhibited AChE, 16–65% for VX-inhibited AChE, 0–8% for tabun-inhibited AChE, and 0–4% for soman-inhibited AChE. The 2-hydroxyimino derivatives protect human erythrocyte AChE and purified bovine erythrocyte AChE from inhibition by soman.

Spectrophotometric behaviour of quinolinium oxime-palladium(II) complexes

SummaryIt has been established that 1-(2-phenyl-2-hydroxyiminoethyl)-1-quinolinium chloride, 1-(2-phenyl-2-hydroxyiminoethyl)-1-isoqui-nolinium chloride, 1-(2-phenyl-2-hydroxyiminoethyl)-1-(4′-methyl)-quinolinium chloride and 1-(2-phenyl-2-hydroxyiminoethyl)-1-(6′-methyl)quinolinium chloride react with palladium(II) chloride in the pH range 3.3–7.1 and form yellow water-soluble 1∶1 complexes with maximum absorbance at 413 nm. The conditional stability constants of the complexes at the optimum pH of 6.5 are all about 104.7, and the molar absorptivities are in the range 2.2–2.6×103 l·l mole−1·cm−1 at pH 6.5 and 413 nm. Beers law is obeyed up to 3–4×10−4M oxime concentration, depending on the oxime determined.