54079-33-3Relevant academic research and scientific papers
Sulfur Derivatives of 2-Oxopropanal Oxime as Reactivators of Organophosphate-Inhibited Acetylcholinesterase in Vitro: Synthesis and Structure-Reactivity Relationships
Degorre, Francoise,Kiffer, Daniel,Terrier, Francois
, p. 757 - 763 (1988)
We have prepared four new oximes, 1b-e, which conform to the general structure RCH2COCH=NOH where R = CH3S, CH3SO, CH3SO2, and (CH3)2S(+), respectively, and have the same E configuration as the parent 2-oxopropanal oxime 1a (R=H, MINA).The pKa values range from 6.54 (1e) to 8.16 (1b), as compared with 8.30 for 1a.Rates of reaction (k1) with 4-nitrophenyl acetate indicate that the oximate anions have a much higher nucleophilicity than common oxyanions of similar basicities: the α effects measured for 1a-e are of the order of 200-250.The abilities of 1b-e to reactivate acetylcholinesterase (AChE) inhibited by organophosphates have been evaluated.In vitro experiments reveal a significant reactivation potency of 1b-e against VX-, sarin-, and paraoxon-inhibited immobilized eel AChE.The highly lipophilic methylthio oxime 1b (log P > 1) is intrinsically (k2) 3 times more reactive than the more basic MINA (log P 1).The sulfonium oxime 1e is a potent reactivator against paraoxon.Interestingly, both 1b and 1e have a low toxicity and they exhibit a significant antidotal effect at a relative low dose against paraoxon in rats.
The effect of solvation on the reactivity of α-nucleophiles in aqueous solution. 1. Oximate anions
Terrier, Francois,Degorre, Francoise,Kiffer, Daniel,Laloi, Marguerite
, p. 415 - 419 (2007/10/02)
A kinetic study of the nucleophilic attack of an homogeneous series of α-ketoaldoximate anions of moderate basicity (pKa=6.54-8.30) on p-nitrophenyl acetate in aqueous solution is reported.The corresponding Broensted plot is linear at low pKa with a slope (βnuc ca. 0.7) that is as large as that found for normal oxyanions like phenoxide anions but shows very strong downward curvature at pKa > 7.8.Is is shown that the observed curvature fits very well the data previously obtained for a number of more basic oximate anions (pKa=8-11), suggesting that the phenomenon is typical for the behaviour of these bases.An explanation in terms of a requirement for desolvation of the oximate anion before nucleophilic attack which is more difficult with more basic oximate anions is proposed.
