Search

Results show that human acetylcholinesterase adducts containing organophosphorous toxic agents with P-N derivation and those with phosphonates age by different mechanisms. Present study is the first report to show that acetylcholinesterase adducts containing toxic P-N agents age through P-N bond scission.

The NMR spectra of several N-Boc-amino acids and their methyl esters indicate that hydrogen bonding stabilizes the syn-rotamers of the Boc-carbamate analogs of alpha-amino acids. Specifically, temperature- and concentration-dependent hydrogen bonding with carboxylic groups in solution was found to induce the formation of an unusual carbamate species corresponding to the syn-rotamer of unsaturated N-Boc-amino acids in addition to the expected product. This effect held true for all species studied, including N-Boc-alpha-aminobutyric acid, N-Boc-(4-methoxyphenyl)glycine and a saturated analog of N-Boc vinylglycine.

The degradation of the warfare agent sulfur mustard (HD) adsorbed onto KF/[Al.sub.2][O.sub.3] sorbents is described and analyzed by MAS NMR. The detoxification of the blister agent has showed the formation of nontoxic substitution and less-toxic elimination products and the reaction rates are affected by MAS conditions.

The origins of human acetylcholinesterase (HuAChE) stereoselectivity toward the enantiomers of VX through comparisons with their noncharged isosteres as well as with the symmetrical diethyl phosphates echothiophosphate and its noncharged analogue are investigated. The results indicate that the differential reactivity toward the O-ethyl S-[2[(diisopropylamino)ethyl]methylphosphonothioate (VX) enantiomers is mainly a result of a different interaction of the charged leaving group with Asp74.

The fate of chemical warfare agent VX (0-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate) in various urban matrixes was monitored utilizing 31P MAS NMR. Chosen matrixes represent buildings, roads, pavement, and earth found in urban environments. In view of the high toxicity of VX, solid state NMR afforded a fairly safe experimental mode, omitting any chance for evaporation. Moreover, due to the nondestructive nature of these experiments, measurements could be repeated over and over using the same samples. Degradation rates of VX were obtained and compared to provide a list of relative reactivity toward VX: concrete ⪢ desert sand > beach sand > asphalt ≈ bitumen sheet. Chemical interactions between VX, its degradation products, and the matrixes were often expressed by widening of the peaks to the extent that mass balance could not be achieved. It is noteworthy that these experiments were usually carried out on crushed or milled specimens, allowing high reactivity and rapid reactions. [ABSTRACT FROM AUTHOR]