Showing papers on "Cyanide published in 1992"
TL;DR: Findings indicate a causal role in konzo of sustained high blood cyanide concentrations maintained by a deficient sulphur intake impairing cyanide to thiocyanate conversion, but a minor improvement of food processing may, as in beri-beri, be preventive.
270 citations
TL;DR: The combination of sodium thiosulfate and sodium nitrite has been used in the United States since the 1930s as the primary antidote for cyanide intoxication but could not be used prophylactically because each exhibits a number of side effects.
Abstract: The combination of sodium thiosulfate and sodium nitrite has been used in the United States since the 1930s as the primary antidote for cyanide intoxication. Although this combination was shown to exhibit much greater efficacy than either ingredient alone, the two compounds could not be used prophylactically because each exhibits a number of side effects. This review discusses the pharmacodynamics, pharmacokinetics, and toxicology of the individual agents, and their combination.
160 citations
TL;DR: In this paper, the speciation of dissolved cyanide was studied under pH and redox conditions relevant to soil and groundwater environments, and it was shown that the free cyanide form will predominate at chemical equilibrium in the soil.
Abstract: In order to improve the assessment of the bioavailability and behavior of cyanide in the environment, the speciation of dissolved cyanide was studied under pH and redox conditions relevant to soil and groundwater environments. The partition of cyanide over free cyanide [HCN(aq)+ CN - ] and iron cyanide complexes [or hexacyanoferrates, e.g., Fe(CN) 6 3- and Fe(CN) 6 4- ] at thermodynamic equilibrium was calculated as a function of pH and redox potential. These calculations show that the free cyanide form will predominate at chemical equilibrium in the soil
143 citations
TL;DR: The enzymes which utilize cyanide as a substrate can be categorized into the following reaction types: substitution/addition, hydrolysis, oxidation, and reduction, which are reviewed with respect to the known biochemistry and feasibility for use in treatment of cyanide containing wastes.
Abstract: Cyanide is an important industrial chemical produced on a grand scale each year. Although extremely toxic to mammalian life, cyanide is a natural product generated by fungi and bacteria, and as a result microbial systems have evolved for the degradation of cyanide to less toxic compounds. The enzymes which utilize cyanide as a substrate can be categorized into the following reaction types: substitution/addition, hydrolysis, oxidation, and reduction. Each of these categories is reviewed with respect to the known biochemistry and feasibility for use in treatment of cyanide containing wastes.
137 citations
TL;DR: In this article, it was found that high residual levels of cyanohydrin, an intermediate breakdown product of the cyanogenic glucoside, was the principal source of dietary cyanide exposure.
127 citations
TL;DR: In this paper, the vertical electron affinities of temporary negative ion states of HCN, CH{sub 3}CN, CH {sub 2}(CN){sub 2}, acrylonitrile, fumaronitrile and benzonitrile were determined using electron transmission spectroscopy and molecular orbital calculations.
Abstract: The vertical electron affinities of temporary negative ion states of HCN, CH{sub 3}CN, CH{sub 2}(CN){sub 2}, acrylonitrile, fumaronitrile, benzonitrile, tetracyanoquinodimethane, and tetracyanoethylene are determined using electron transmission spectroscopy and molecular orbital calculations.
105 citations
TL;DR: The growth of Pseudomonas fluorescens NCIMB 11764 on cyanide as the sole nitrogen source was accomplished by use of a modified fed-batch cultivation procedure and the relative yields of all four metabolites (CO2, formamide, formate, and ammonia) were shown to be dependent on the KCN concentration and availability of oxygen.
Abstract: The growth of Pseudomonas fluorescens NCIMB 11764 on cyanide as the sole nitrogen source was accomplished by use of a modified fed-batch cultivation procedure. Previous studies showing that cyanide metabolism in this organism is both an oxygen-dependent and an inducible process, with CO2 and ammonia representing conversion products, were confirmed. However, washed cells (40 mg ml-1 [dry weight]) metabolized cyanide at concentrations far exceeding those previously described; 85% of 50 mM KCN was degraded in 6 h. In addition, two other C1 metabolites were detected in incubation mixtures; their identities were confirmed as formamide and formate by 13C nuclear magnetic resonance spectrocopy, high-pressure liquid chromatography, radioisotopic trapping experiments, and other analytical means. The relative yields of all four metabolites (CO2, formamide, formate, and ammonia) were shown to be dependent on the KCN concentration and availability of oxygen; at 0.5 to 10 mM substrate, CO2 was the major C1 product, whereas at 20 and 50 mM substrate, formamide and formate were principally formed. The latter two metabolites also accumulated during prolonged anaerobic incubation, suggesting that P. fluorescens NCIMB 11764 can elaborate several pathways of cyanide conversion. One is formally similar to that proposed previously (R. E. Harris and C. J. Knowles, FEMS Microbiol. Lett. 20:337-341, 1983), involving the oxygen-dependent conversion of cyanide to CO2 and ammonia. The other two, occurring in the presence or absence of oxygen, involve separate reactions to yield, respectively, formate plus ammonia or formamide.(ABSTRACT TRUNCATED AT 250 WORDS)
100 citations
TL;DR: Results indicate that both CORT and glutamate can potentiate hypoxia-induced energy failure in hippocampal astrocytes, albeit by different mechanisms.
78 citations
TL;DR: A flavomonooxygenase, pentachlorophenol hydroxylase, isolated from a Flavobacterium sp.
Abstract: An understanding of the enzymatic reactions catalyzing the degradation of substituted phenols, a major group of environmental pollutants, is required for the development of biological methods for the decontamination of halophenol-polluted sites. We found that a flavomonooxygenase, pentachlorophenol hydroxylase, isolated from a Flavobacterium sp., catalyzed a primary attack on a broad range of substituted phenols, hydroxylating the para position and removing halogen, nitro, amino, and cyano groups to produce halide, nitrite, hydroxylamine, and cyanide, respectively. Elimination of 1 mol of a halogen, nitro, or cyano group required 2 mol of NADPH, while only 1 mol of NADPH was required to remove 1 mol of an amino group or hydrogen.
75 citations
TL;DR: In this article, a plug flow digester (Transpaille) was used to solve the problem of acidification through localization of the acidogenic phase in the first half of the fermenter and nitrogen deficiency because a permanent liquid phase allowed nitrogen accumulation.
72 citations
TL;DR: Data indicate that in tobacco cell-suspension culture, SA induces the activity and the capacity of cyanide-resistant respiration without affecting thecapacity of the cytochrome c respiration pathway.
Abstract: Cyanide-resistant, alternative respiration in Nicotiana tabacum L. cv Xanthi-nc was analyzed in liquid suspension cultures using O(2) uptake and calorimetric measurements. In young cultures (4-8 d after transfer), cyanide inhibited O(2) uptake by up to 40% as compared to controls. Application of 20 mum salicylic acid (SA) to young cells increased cyanide-resistant O(2) uptake within 2 h. Development of KCN resistance did not affect total O(2) uptake, but was accompanied by a 60% increase in the rate of heat evolution from cells as measured by calorimetry. This stimulation of heat evolution by SA was not significantly affected by 1 mm cyanide, but was reduced by 10 mm salicylhydroxamic acid (SHAM), an inhibitor of cyanide-resistant respiration. Treatment of SA-induced or uninduced cells with a combination of cyanide and SHAM blocked most of the O(2) consumption and heat evolution. Fifty percent of the applied SA was taken up within 10 min, with most of the intracellular SA metabolized in 2 h. 2,6-Dihydroxybenzoic and 4-hydroxybenzoic acids also induced cyanide-resistant respiration. These data indicate that in tobacco cell-suspension culture, SA induces the activity and the capacity of cyanide-resistant respiration without affecting the capacity of the cytochrome c respiration pathway.
TL;DR: In this article, the reaction of p-toluenesulphonyl cyanide or methanesulfonyl cyanides with carbon radicals, generated from the corresponding O-acyl-N-hydroxy-2-thiopyridone derivatives by visible light photolysis gives nitriles in good yield.
TL;DR: 1H NMR spectra of manganese peroxidase from Phanerochaete chrysosporium and of its cyanide derivative are reported and the shift pattern of the protons of the proximal histidine is discussed relative to the structural properties which affect the Fe3+/Fe2+ redox potential.
Abstract: 1H NMR spectra at 200- and 600-MHz of manganese peroxidase from Phanerochaete chrysosporium and of its cyanide derivative are reported. The spectrum of the native protein is very similar to that of other peroxidases. The assignment of the spectrum of the cyanide derivative has been performed through 1D NOE, 2D NOESY, and COSY experiments. This protein is very similar to lignin peroxidase, the only meaningful difference being the shift of H delta 2 of the proximal histidine. The spectra of the cyanide derivative of these two proteins are compared with those of horseradish peroxidase and cytochrome c peroxidase. The shift pattern of the protons of the proximal histidine is discussed relative to the structural properties which affect the Fe3+/Fe2+ redox potential.
TL;DR: In this paper, the disappearance of CN −, consumption of O 2, formation of OCN − an intermediate and ultimate mineralization to CO 2 and N 2 were quantitatively determined and a large-scale photoreactor was also manufactured, which is an excellent device for the photodecomposition of a large amount of cyanide.
Abstract: A reagent KCN solution and an industrial wastewater containing CN − can be efficiently degraded photocatalytically in aqueous TiO 2 semiconductor dispersions. The disappearance of CN − , consumption of O 2 , formation of OCN − an intermediate and ultimate mineralization to CO 2 and N 2 were quantitatively determined. A large-scale photoreactor (5 l) was also manufactured, which is an excellent device for the photodecomposition of a large amount of cyanide.
TL;DR: Simultaneous infusion of thiosulfate with nitroprusside provides the sulfur donor necessary to prevent cyanide accumulation and eliminates the possibility of cyanide intoxication without altering the efficacy of nitroPRusside.
Abstract: Sodium nitroprusside is an antihypertensive agent used frequently in the critical care setting. Recently, the Food and Drug Administration (FDA) published a report that led to a labeling change emphasizing the pharmacokinetics of nitroprusside with metabolism to highly toxic cyanide. Although evidence validates that cyanogenesis occurs with nitroprusside administration, prevention and treatment of cyanide poisoning is rarely instituted in clinical practice. Simultaneous infusion of thiosulfate with nitroprusside provides the sulfur donor necessary to prevent cyanide accumulation. Cyanide combines with thiosulfate to form the less toxic sodium thiocyanate, which is then excreted. A 10:1 ratio of nitroprusside to thiosulfate in the infusion eliminates the possibility of cyanide intoxication without altering the efficacy of nitroprusside.
TL;DR: The overall incidence appears to be infrequent; however, certain patients may be at high risk because of risk factors that may include hypoalbuminemia, cardiopulmonary bypass procedures, or the administration of moderate to high doses of nitroprusside.
Abstract: OBJECTIVE:To review the risks, manifestations, and treatment of cyanide toxicity from nitroprusside therapy.DATA SOURCES:All English case reports identified in Index Medicus (MEDLINE) of cyanide intoxication related to nitroprusside from 1970 to the present were reviewed. In addition, literature regarding the incidence, risks, and treatment of cyanide toxicity from nitroprusside is presented.CONCLUSIONS:Numerous cases of cyanide toxicity associated with nitroprusside have been reported. The overall incidence appears to be infrequent; however, certain patients may be at high risk. Risk factors may include hypoalbuminemia, cardiopulmonary bypass procedures, or the administration of moderate to high doses of nitroprusside. Treatment of cyanide toxicity requires the cessation of nitroprusside and, for severe toxicity, use of the cyanide antidote kit. Cyanide toxicity from nitroprusside may be prevented by concomitant administration of sodium thiosulfate infusions.
TL;DR: A method for the determination of cyanide in human red cells has been developed by reversed-phase high-performance liquid chromatography with fluorescence detection, which recovery from red cells was 83%, and the limit of detection was 100 pmol/ml.
TL;DR: The guanidine ion pairing functionality, which exists in its protonated form at pH 13.5, has been shown to be feasible for leach-SX-EW technology in the gold industry.
TL;DR: In this paper, the addition of cyanide occurs at the least substituted carbon, which is the case for β-hydroxy nitriles with stoichiometic triethylamine.
TL;DR: The results support a model in which one CN- binds through the carbon atom to ferrous a3, supporting a low-spin (S = 0) configuration on the Fe; bridging by this cyanide to the CuB is weak or absent.
Abstract: Cytochrome ba3 from Thermus thermophilus reacts slowly with excess HCN at pH 7.4 to create a form of the enzyme in which CuA, cytochrome b, and CuB remain oxidized, while cytochrome a3 is reduced by one electron, presumably with the formation of cyanogen. We have examined this form of the enzyme by UV-visible, resonance Raman, EPR, and electron nuclear double resonance spectroscopies in conjunction with permutations of 13C- and 15N-labeled cyanide. The results support a model in which one CN- binds through the carbon atom to ferrous a3, supporting a low-spin (S = 0) configuration on the Fe; bridging by this cyanide to the CuB is weak or absent. Four 14N atoms, presumably donated by histidine residues of the protein, provide a strong equatorial ligand field about CuB; a second CN- is coordinated through the carbon atom to CuB in an axial position.
TL;DR: The kinetics of the enzymatic degradation of cyanide were studied in a batch reactor using the powdered immobilized enzyme preparation and modeled using a simple Michaelis‐Menten equation.
Abstract: CYANIDASE@ is a new enzyme preparation capable of degrading cyanide in industrial wastewaters to ammonia and formate in an apparently one-step reaction, down to very low concentrations. This enzyme has both a high selectivity and affinity toward cyanide. A granular form of the biocatalyst was used in a recirculation fixed bed reactor in order to characterize the new biocatalyst with respect to pH, ionic strength, common ions normally present in wastewaters, mass transfer effects, and temperature. Long term stability was investigated. The kinetics of the enzymatic degradation of cyanide were studied in a batch reactor using the powdered immobilized enzyme preparation and modeled using a simple Michaelis-Menten equation.
TL;DR: Pseudomonas putida, a saprophytic root-colonizing bacterium, produces multiple forms of catalase, which increases in specific activity during growth phase and after treatment with H2O2.
Abstract: Pseudomonas putida, a saprophytic root-colonizing bacterium, produces multiple forms of catalase. Catalase A, which increases in specific activity during growth phase and after treatment with H2O2, is located in the cytoplasm and is inhibited by 3-amino-1,2,4-triazole, EDTA, and cyanide, but not by chloroform–methanol treatment. Catalase B, which is induced by external H2O2 or during stationary phase of growth, is membrane associated and is inhibited by chloroform–methanol, EDTA, and cyanide, but not by aminotriazole. Catalase A has a broad pH optimum, from pH 6.0 to 11.0, with two peaks, at pH 8.0 and 11.0. Catalase B is most active at pH 5.0–11.0. Mutant J-1, generated by ethyl methanesulfonate mutagenesis, lacked catalase A activity in extracts of cells harvested throughout lag to early stationary growth phase in liquid medium. Catalase B was produced by J-1 in stationary phase. Exposure of J-1 to H2O2 caused the production of both catalase A and catalase B. Mutant J-1 was more susceptible to cell deat...
Patent•
30 Jan 1992
TL;DR: An apparatus and method for treating streams containing cyanide, heavy metal and precious metal values to recover those values where the method includes the following steps: a) providing a membrane filtration means having an inlet, a product outlet and an discharge outlet, b) contacting the waste stream to be treated with an effective amount of carbon dioxide to adjust the pH to about 8.0 to about 10.
Abstract: An apparatus and method for treating streams containing cyanide, heavy metal and precious metal values to recover those values where the method includes the following steps: a) providing a membrane filtration means having an inlet, a product outlet and an discharge outlet, b) contacting the waste stream to be treated with an effective amount of carbon dioxide to adjust the pH to about 8.0 to about 10.0, c) further contacting the waste stream with an effective amount of a soluble metal compound to react with the cyanide in the waste stream to form membrane rejectable cyanide compounds, and d) passing the treated stream through the membrane filtration means to thereby separate recoverable cyanide and precious metal values from the treated stream and produce an effluent stream for further processing or discharge to the environment.
TL;DR: The data support a hypothesis on a catalase cycle catalysed by cylochrome c oxidase in the presence of excess H2O2 that superoxide dismutase is shown to affect spectral changes observed upon cytochroma c oxidation reaction with H2 O2.
TL;DR: Two isomeric compounds (α and β) of the composition Cu{N(CN)2}2(imidazole)2 were prepared and studied by IR, far-IR, electronic and ESR spectra, as well as by temperature-dependent (down to 4.2 K) magnetic susceptibility measurements as mentioned in this paper.
TL;DR: Evidence is presented suggesting that mediation of electron transfer from one-electron-reduced, cyanide-liganded enzyme to free, ferric oxidase, rather than a global protein conformational change of the enzyme, is responsible for the greatly enhanced cyanide binding rates seen in the presence of cytochrome c or poly(L-lysine.
TL;DR: The analysis of gold deportment with the diagnostic leaching technique has opened a research field to gain more insight into the fundamentals of the kinetic behaviour of gold dissolution from refractory ores as discussed by the authors.
TL;DR: The photocatalytic oxidation of cyanide at titanium(IV) oxide powder induced by UV irradiation was investigated in this article, where it was verified that cyanide is first oxidized to cyanate.
Abstract: The photocatalytic oxidation of cyanide at titanium(IV) oxide powder induced by UV irradiation was investigated. It is verified that cyanide is first oxidized to cyanate. However, contrary to earlier studies, it is established that cyanate is subsequently further photocatalytically oxidized via nitrite all the way to nitrate. Experimental conditions were varied and the effects of various sparging gases and pH, as well as the concentrations of both cyanide and photocatalyst, were investigated. As nitrate is a significantly less hazardous contaminant than cyanide, complete photocatalytic oxidation of cyanide to nitrate may be a viable method for decontamination of cyanide wastes.
TL;DR: In this paper, α-aminonitriles and bis(α-)aminonitrile are prepared by adding a primary amine to a mixture of aldehyde/trimethylsilyl cyanide (TMSCN).
TL;DR: A rapid, inexpensive screening assay was developed in order to measure the cyanide content of cassava (Manihot esculenta Crantz) tubers and the intensity of the blue colour which developed within one hour was rated visually on a graded scale from 0 to 5.
Abstract: A rapid, inexpensive screening assay was developed in order to measure the cyanide content of cassava (Manihot esculenta Crantz) tubers. A small disc of parenchyma tissue cut with a cork borer or alternatively grated tissue was placed in a stoppered glass tube and the hydrogen cyanide liberated produced a blue colour on a filter paper previously spotted with a drop of tetra-base [4,4'-methylenebis-(N,N-dimethylaniline)] and cupric acetate. The intensity of the blue colour which developed within one hour was rated visually on a graded scale from 0 to 5. The correlation coefficient between samples accurately analysed for total cyanide and also tested using the rapid assay was 0.77.