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[en] The aim of this study is to investigate the ability of intramuscular and intravenous sulfanegen sodium treatment to reverse cyanide effects in a rabbit model as a potential treatment for mass casualty resulting from cyanide exposure. Cyanide poisoning is a serious chemical threat from accidental or intentional exposures. Current cyanide exposure treatments, including direct binding agents, methemoglobin donors, and sulfur donors, have several limitations. Non-rhodanese mediated sulfur transferase pathways, including 3-mercaptopyruvate sulfurtransferase (3-MPST) catalyze the transfer of sulfur from 3-MP to cyanide, forming pyruvate and less toxic thiocyanate. We developed a water-soluble 3-MP prodrug, 3-mercaptopyruvatedithiane (sulfanegen sodium), with the potential to provide a continuous supply of substrate for CN detoxification. In addition to developing a mass casualty cyanide reversal agent, methods are needed to rapidly and reliably diagnose and monitor cyanide poisoning and reversal. We use non-invasive technology, diffuse optical spectroscopy (DOS) and continuous wave near infrared spectroscopy (CWNIRS) to monitor physiologic changes associated with cyanide exposure and reversal. A total of 35 animals were studied. Sulfanegen sodium was shown to reverse the effects of cyanide exposure on oxyhemoglobin and deoxyhemoglobin rapidly, significantly faster than control animals when administered by intravenous or intramuscular routes. RBC cyanide levels also returned to normal faster following both intramuscular and intravenous sulfanegen sodium treatment than controls. These studies demonstrate the clinical potential for the novel approach of supplying substrate for non-rhodanese mediated sulfur transferase pathways for cyanide detoxification. DOS and CWNIRS demonstrated their usefulness in optimizing the dose of sulfanegen sodium treatment.
[en] Second-order rate constants (kCN-) have been measured for nucleophilic substitution reactions of Y-substituted phenyl benzoates (1a-r) with CN. ion in 80 mol % H2O/20 mol % DMSO at 25.0 ± 0.1 .deg. C. The Bronsted-type plot is linear with βlg = .0.49, a typical βlg value for reactions reported to proceed through a concerted mechanism. Hammett plots correlated with σ.deg. and σ- constants exhibit many scattered points. In contrast, the Yukawa-Tsuno plot for the same reaction exhibits excellent linearity with ρY = 1.37 and r = 0.34, indicating that a negative charge develops partially on the oxygen atom of the leaving aryloxide in the rate-determining step (RDS). Although two different mechanisms are plausible (i.e., a concerted mechanism and a stepwise pathway in which expulsion of the leaving group occurs at the RDS), the reaction has been concluded to proceed through a concerted mechanism on the basis of the magnitude of βlg and ρY values
[en] Complete text of publication follows. The involvement of high-valent iron-oxo intermediates in biological, environmental, and industrial processes is of current interest. FeVIO42- is relatively stable and is a potential oxidant in 'green' treatment of polluted waters. By contrast, Fe(V) and Fe(IV) are short-lived transients when produced in aqueous solution in the absence of strongly bonding ligands other than hydroxide, a feature that has limited studies of its reactivity. FeVO43- and FeIVO44- have been suggested to be the intermediates in the oxidation of inorganic and organic compounds by FeVIO43-. FeVO43- can be generated easily in the presence of excess FeVIO42- through the use of reducing carbon-centered radicals produced in pulse radiolysis. The decay of the oxyiron(V) species is dependent on pH, where completely deprotonated FeVO43- decays to a longer lived transient (t1/2 ∼ seconds) via a first-order process. However, as the pH is lowered, oxyiron(V) disappears by second-order kinetics to form ferric ions and hydrogen peroxide. The second order rate constant observed in the disappearance of Fe(V) increases as the pH is lowered and is of the order of 107 M-1s-1. Oxyiron(IV) complex with a simple inorganic ligand, P2O74- in basic medium can be generated from the corresponding parent complex by oxidation with OH/O- radical in aqueous solutions. The pyrophosphate complex of iron(IV), formed at pH ≥ 10 is short lived (t1/2 = 100-600 ms). This complex of iron(IV) disappears by a second order process to form a Fe(III) pyrophosphate complex and molecular oxygen. A premix pulse radiolysis was used to measure the reactivity of FeVIO42-, FeVO43-, and FeIVO44- with cyanides, oxysulfur species, and aminopolycarboxylates (APCs) and their radicals. The oxidation rates decrease with increase in pH and are, in the order of FeVO43- > FeIVO44- > FeVIO42-. Reduction rate constants of FeVIO42- to FeVO43- by ·CONH2, ·SO3- and S4O6·3- radicals were found to be 2.6 ± 0.6 x 109, 1.9 ± 0.3 x 108 and 7.5 ± 0.8 x 107 M-1 s-1. The oxidation of cyanides by Fe(V) indicate a two-electron transfer with SCN- while one-electron reduction of FeV to FeIV to FeIII takes place in case of CN-. The formation of a Fe(IV)-cyano complex in reduction of FeV by metalcyanide will be discussed. The reaction rates of FeVO43- with the two oxysulfur ions were separated by an order of magnitude, with SO32- reacting at 3.9 ± 0.3 x 104 while S2O32- reacted with Fe(V) at 2.1 ± 0.1 x 103 M-1 s-1 at pH 11.4. Measurements for FeVO43- reactivity with oxy-sulfur species suggest two-electron reduction. Fe(V) reactivity with APCs at pH 12.5 increase in order tertiary < secondary < primary amines and proceed via a two-electron oxidation.
[en] Published data on the use of cyanoacetamides, cyanothio- and -selenoacetamides in fine organic synthesis and the prospects of application of these compounds in combinatorial synthesis are analysed and generalised. The bibliography includes 653 references.
[en] Attempted suicide by cyanide poisoning causes rapid death by inhibition of cell-mediated oxidation. There are few cases of survival and most reports on the victims involve postmortem pathological studies. We present the case of a long-term survivor who developed parkinson, focusing especially on the contribution of neuroimaging to the diagnosis and follow-up. (Author) 15 refs
[en] Hydroxocobalamin has been used as a cyanide poisoning antidote for many years in France. It has recently been approved by the US FDA. In Paris, hydroxocobalamin is carried by the Brigade de Sapeurs Pompiers (Paris Fire Brigade) in mobile intensive care vehicles and has been administered empirically to victims of enclosed-space fire smoke inhalation who meet the criteria of having soot in the nose, mouth, or throat, any alteration in mental status or disturbance in consciousness, and especially if any degree of hypotension is present (BP less than or equal to 100 mmHg systolic). The administration of hydroxocobalamin at the scene was shown to be safe. Hydroxocobalamin has also been efficacious and safe in 'pure' cyanide poisoning, as long as brain death has not already occurred. A 'toxidrome' of cyanide poisoning has been developed in our institution in Paris, and its application can assist in making the diagnosis of this life-threatening poisoning which cannot be emergent diagnosed by currently-available laboratory methods.(author)
[en] Nucleophilic substitution of benzyl-type chlorides with cyanide ion in deuterochloroform, deuteroacetonitrile or deuterobenzene catalyzed by 18-crown-6 results in the introduction of deuterium onto the benzyl carbon. Benzyl cyanides are labelled by refluxing with cyanide ion and crown ether in deutero solvent. Two such exchanges in deuterochloroform produced greater than 90% incorporation. Side-chain labelled phenylethylamine, tryptamine and m- and p-tyramine were synthesized in this way. (author)
[en] A novel colorimetric and fluorescent sensor 6 for fluoride and cyanide was developed based on BODIPY-coumarin platform and its anions sensing properties were investigated in the mixture of acetonitrile and Tris–HCl buffer (v/v = 95:5, pH = 7.5). Probe 6 could simultaneously detect F– and CN– through colorimetric method over the other competitive anions, such as Cl–, Br–, I–, NO3–, ClO4–, HSO4–, S2– and H2PO4–. It exhibited a distinct color change from red to green upon addition of F– through deprotection of tert-butyldiphenylsilyl group of coumarin. Moreover, it displayed an obvious color change from red to yellow through deprotection process firstly, then with a nucleophilic displacement mechanism. Therefore, the sensor 6 provides a novel method to simultaneously detect F− and CN− with different color change in the same solvent environment. The detection limit of sensor 6 toward F– and CN– ion was determined to be 0.43 μM and 1.9 μM respectively,