Pd(II) complexes of acetylcholinesterase reactivator obidoxime
نویسندگان
چکیده
The ability of the acetylcholinesterase reactivator obidoxime (H2L(2+)) to bind palladium(II) cations was evaluated spectrophotometrically at different reaction conditions (pH, reaction time, metal-to-ligand molar ratio). The results showed that immediately after mixing the reagents, pH 7.4, complex species of composition [PdHL](3+) existed predominantly with a value of conditional stability constant lgβ'=6.52. The reaction was completed within 24 hours affording the formation of species [Pd2L](4+) with significantly increased stability (lgβ'=9.34). The spectral data suggest that obidoxime coordinates metal(II) ions through the oximate functional groups. The in vitro reactivation assay of paraoxon-inhibited rat brain acetylcholinesterase revealed that the new complex species were much less active than the non-coordinated obidoxime. The lack of reactivation ability could be explained by the considerable stability of complexes in solution as well as by the deprotonation of oxime groups essential for recovery of the enzymatic activity.
منابع مشابه
Reactivation potency of the acetylcholinesterase reactivator obidoxime is limited.
BACKGROUND Obidoxime is the only one reactivator of acetylcholinesterase (AChE) approved in Czech Republic for the treatment of nerve agent and pesticide poisonings for civilian sector. Due to the fact that misuse of nerve agents by terrorists or by an accidental poisoning by farmers is possible, re-evaluation of its universality is needed. It is also needed by the fact that clinical findings c...
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