Showing papers on "Thiocyanate published in 1989"
TL;DR: The method, which was applicable to both Gram‐positive and Gram‐negative bacteria, eliminated endogenous nuclease activity and avoided the need for phenol, RNase and protease treatments.
Abstract: A method is described for the rapid isolation and purification of bacterial genomic DNA. A total of 215 bacterial strains representing species of Campylobacter, Corynebacterium, Escherichia, Legionella, Neisseria, Staphylococcus and Streptococcus, were lysed with guanidium thiocyanate. DNA was prepared using just three other reagents and one high-speed centrifugation step. The method, which was applicable to both Gram-positive and Gram-negative bacteria, eliminated endogenous nuclease activity and avoided the need for phenol, RNase and protease treatments. The DNA was of high purity, high molecular mass and double-stranded.
2,148 citations
TL;DR: Lysozyme thiocyanate and nitrate crystals belong to the monoclinic system, whereas all the others have a tetragonal lattice, and SCN- precipitates and crystallizes lysozyme at low concentration, whereas sulfate is ineffective even at high concentrations.
328 citations
TL;DR: The response properties of a new solvent/polymeric membrane electrode with unique selectivity toward anionic salicylate are reported, and it is shown that the metal center of the metalloporphyrin is critical for selective salicyllate transport in the membrane phase.
Abstract: The response properties of a new solvent/polymeric membrane electrode with unique selectivity toward anionic salicylate are reported. The electrode is prepared by incorporating 5, 10, 15, 20-tetraphenyl(porphyrinato)tin(IV) dichloride (Sn[TPP]Cl2) into a plasticized poly(vinyl chloride) membrane. The resulting sensor exhibits an anti-Hofmeister selectivity pattern, with high specificity for salicylate over lipophilic inorganic anions (perchlorate, periodate, thiocyanate, iodide, etc.) and biological organic anions (citrate, lactate, acetate). Moderate selectivity over structural analogues of salicylate (3- and 4-hydroxybenzoate, benzoate) is also observed. Radiotracer uptake experiments using [14C]salicylate clearly show that the metal center of the metalloporphyrin is critical for selective salicylate transport in the membrane phase. Minimal response to chloride ions makes the new electrode potentially useful for estimating salicylate levels in biological samples.
195 citations
TL;DR: In this paper, the electrochemical oxidation of BEDT-TTF with Hg(SCN)2, KSCN, and 18crown-6 ether yielded two different BEDTs of mercury(II) thiocyanate depending on the solvent used.
Abstract: The electrochemical oxidation of BEDT-TTF with Hg(SCN)2, KSCN, and 18-crown-6 ether yielded two different BEDT-TTF salts of mercury(II) thiocyanate depending on the solvent used. The K+ containing salt, (BEDT-TTF)2[KHg(SCN)4], was metallic down to 1.5 K with various temperature dependences. The crystal structures showed an alternating stacking of two-dimensional networks of BEDT-TTF molecules and of KHg(SCN)4 anions. The other modification (BEDT-TTF)3[Hg(SCN)3] exhibited metal-insulator (MI) transition at around 180 K.
75 citations
TL;DR: A combination of three automated methods has been developed to determine total cyanide, free cyanide [i.e., HCN(aq)+ CN–], iron-cyanide complexes and thiocyanate, and Shielding the samples from diffuse daylight appeared to be necessary to prevent rapid photolysis of the iron-cyclic complexes.
Abstract: A combination of three automated methods has been developed to determine total cyanide, free cyanide [i.e., HCN(aq)+ CN–], iron-cyanide complexes and thiocyanate. The methods are based on a continuous-flow technique, combined with spectrophotometric detection, and have a detection limit of 0.6 µg l–1. The distinction between iron-cyanide complexes and free cyanide plus thiocyanate was made by UV irradiation and distillation with citric acid. The distinction between free cyanide and thiocyanate was made by masking free cyanide with formaldehyde. Rapid and complete recovery of iron-cyanide complexes was obtained; the interference from nitrate was minimised. Shielding the samples from diffuse daylight appeared to be necessary to prevent rapid photolysis of the iron-cyanide complexes.
61 citations
60 citations
TL;DR: In this paper, D. desulfuricans can generate a proton gradient by pumping protons across the cytoplasmic membrane using electron acceptors and hydrogen pulses.
Abstract: Proton translocation by washed cells of the sulfate-reducing bacterium Desulfovibrio desulfuricans strain Essex 6 was studied by means of pH and sulfide electrodes. Reversible extrusion of protons could be induced either by addition of electron acceptors to cells incubated under hydrogen, or by addition of hydrogen to cells incubated in the presence of an appropriate electron acceptor. Proton translocation was increased in the presence of ionophores that dissipate the membrane potential (thiocyanate, methyl triphenylphosphonium cation, but not valinomycin) and was sensitive to the uncoupler carbonylcyanide m-chlorophenylhydrazone (CCCP). Upon micromolar additions of H2, usually sulfide was formed in stoichiometric amounts, and extrapolated H+/H2 ratios were 1.8±0.5 with sulfate, 2.3±0.3 with sulfite and 0.5±0.1 with thiosulfate. In several experiments hydrogen pulses caused increased proton extrusion not associated with sulfide production. This was a hint that sulfite might be reduced via intermediates. In the absence of H2S formation, extrapolated H+/H2 ratios were 3.1±0.8 with sulfate, 3.4±1.1 with sulfite, 4.4±0.8 with thiosulfate and 6.3±1.2 with oxygen. Micromolar pulses of electron acceptors to cells incubated under H2 caused less proton translocation than H2 pulses in presence of excess of electron acceptor; extrapolated H+/H2 ratios were 1.3±0.4 with sulfite, 3.3±0.9 with nitrite and 4.2±0.5 with oxygen. No proton translocation was observed after micromolar pulses of sulfate, thiosulfate or nitrate to cells incubated under hydrogen in the presence of thiocyanate. Inhibition experiments with CO and CuCl2 revealed that the hydrogenase activity was localized in the intracellular space, and that no periplasmic hydrogenase was present. The results indicate that D. desulfuricans can generate a proton gradient by pumping protons across the cytoplasmic membrane.
59 citations
53 citations
TL;DR: The pH dependence of line width of 15N resonance of SC15N- in the presence of the enzyme has revealed that the binding of the thiocyanate to the enzyme is facilitated by protonation of an ionizable group (with pKa of 6.4), which is presumably distal histidine.
Abstract: The binding of thiocyanate to lactoperoxidase (LPO) has been investigated by 1H and 15N NMR spectroscopy. 1H NMR of LPO shows that the major broad heme methyl proton resonance at about 61 ppm is shifted upfield by addition of the thiocyanate, indicating binding of the thiocyanate to the enzyme. The pH dependence of line width of 15N resonance of SC15N- in the presence of the enzyme has revealed that the binding of the thiocyanate to the enzyme is facilitated by protonation of an ionizable group (with pKa of 6.4), which is presumably distal histidine. Dissociation constants (KD) of SC15N-/LPO, SC15N-/LPO/I-, and SC15N-/LPO/CN- equilibria have been determined by 15N T1 measurements and found to be 90 +/- 5, 173 +/- 20, and 83 +/- 6 mM, respectively. On the basis of these values of KD, it is suggested that the iodide ion inhibits the binding of the thiocyanate but cyanide ion does not. The thiocyanate is shown to bind at the same site of LPO as iodide does, but the binding is considerably weaker and is away from the ferric ion. The distance of 15N of the bound thiocyanate ion from the iron is determined to be 7.2 +/- 0.2 Amore » from the 15N T1 measurements.« less
49 citations
TL;DR: In this paper, a new solvent/polymeric-membrane electrode which exhibits significant potentiometric response toward sulfite ion in the 1 X 1O-6-1 X 10m3 M range is described.
46 citations
TL;DR: In this article, a thiocyanate-selective solvent-polymeric membrane electrode was proposed for detection of thioxyanate in 22 human saliva samples with good correlation to a classical colorimetric method (r = 0.981).
Abstract: The response properties of a new thiocyanate-selective solvent-polymeric membrane electrode are reported. The membrane contains (5,10,15,20-tetrakis(2,4,6-triphenylphenyl)porphyrinato)manganese(III) chloride (Mn[TPPP]CI) in a plasticized polyvinyl chloride matrix. The electrode deviates from the Hofmeister selectivity pattern by responding to thiocyanate preferentially over inorganic anions (perchlorate, chloride, iodide, and bromide) and several organic anions often present in biological samples (ascorbate, citrate, urate, and salicylate). The performance of this electrode as an ion-selective detector in a low-dispersion, flow-injection system is also evaluated. While selectivity in such a nonequilibrium flow arrangement is found to be somewhat different than that observed under equilibrium conditions, the electrode's response and selectivity is still adequate to allow for measurement of thiocyanate in biological samples. This application is demonstrated via the flow-injection analysis (FIA) detection of thiocyanate in 22 human saliva samples with good correlation to a classical colorimetric method (r = 0.981).
TL;DR: The interaction of aromatic donor molecules with lactoperoxidase (LPO) was studied using 1H-NMR and optical difference spectroscopy techniques and suggested that hydrogen bonding of the donors with the distal histidine amino acid, and hydrophobic interaction between the donors and the active site contribute significantly towards the associating forces.
TL;DR: In this paper, it was found that the vibrational frequency of the C-N stretching mode is dependent upon the nature of the supporting electrolyte cation and the applied electric field within the interfacial region.
TL;DR: Good nitrification and denitrification efficiencies are attainable in the anoxic–oxic activated‐sludge process in the presence of high feed cyanide and thiocyanate concentrations, provided that MCRT is maintained at a desirable level.
Abstract: The anoxic-oxic activated-sludge process has been evaluated in a laboratory investigation as a means for effective treatment of cyanide-laden wastewaters, with phenols used as the organic carbon sources for denitrification reactions. The performance of the process was evaluated at different levels of feed cyanide concentration and mean cell residence time (MCRT). The results obtained indicate that the phenolic compounds used can be effectively used as the organic carbon sources to promote denitrification reactions. The effects of cyanide inhibition on overall TOC removal can be alleviated at longer MCRTs. Between 1.2 and 2.2 g TOC can be utilized per gram NO(2) + NO(3) (-) -N removed in the anoxic chamber depending on the prevailing MCRT. Microbial oxidation of cyanide and thiocyanate which yields ammonia is the main mechanism responsible for the removal of cyanide and thiocyanate observed in the anoxic-oxic activated-sludge process. Excellent removal efficiencies have been observed with feed concentrations up to 60 mg CN(-)/L and 100 mg SCN(-)/L Frequent exposure of autotrophic and aerobic cyanideutilizing microbes does not impede their activities in the oxic environment. Good nitrification and denitrification efficiencies are attainable in the anoxic-oxic activated-sludge process in the presence of high feed cyanide and thiocyanate concentrations, provided that MCRT is maintained at a desirable level. As a result, the microbial degradation of cyanide and thiocyanate in conjunction with nitrification and denitrification to produce innocuous nitrogen gas is feasible in the anoxic-oxic activated-sludge process.
Patent•
28 Sep 1989TL;DR: In this paper, a method for reducing the amount of anionic metal-ligand complex in a solution comprises: (a) contacting the solution with a substance selected from: a compound having the formula: A w B x (OH) y C z ·nH 2 O, wherein A represents a divalent metal cation, B represents a trivalent metalcation, C represents a mono-to tetravalent anion, and w, x, y, z and n satisfy the following: 0.
Abstract: A method for reducing the amount of anionic metal-ligand complex in a solution comprises: (a) contacting the solution with a substance selected from: a compound having the formula: A w B x (OH) y C z ·nH 2 O, wherein A represents a divalent metal cation, B represents a trivalent metal cation, C represents a mono- to tetravalent anion, and w, x, y, z and n satisfy the following: 0≦z≦x≦4≦w≦1/2y and 12≧n≧3/2x; a calcined product of said compound and mixtures thereof; and (b) separating the substance from the solution. A method for removing substantially all metal-cyanide, -thiocyanate, -thiosulfate, -citrate and/or -EDTA complex from a solution containing one or more of said complexes is also disclosed. The latter method comprises contacting the solution with a sufficient amount of substance consisting essentially of a compound selected from: hydrotalcite, calcined hydrotalcite and mixtures thereof.
TL;DR: This method for the rapid colorimetry of cyanide in blood, applicable to patients exposed to toxic levels of cyanides, is based on the König reaction, which produces a chromophore from cyanide as well as thiocyanate.
Abstract: This method for the rapid colorimetry of cyanide in blood, applicable to patients exposed to toxic levels of cyanide, is based on the Konig reaction, which produces a chromophore from cyanide as well as thiocyanate. The latter compound, normally present in blood, is confined to plasma. Thus, its interference with determination of cyanide was eliminated by performing the assay on the erythrocytes, which contain most of the blood cyanide. Furthermore, cyanide was trapped in the erythrocytes and stabilized during the initial washing steps by conversion of hemoglobin to methemoglobin with inorganic nitrite.
TL;DR: The synthesis of 4-thio-D-galactofuranose and derivatives, starting from methyl a-Dglucopyranoside (l), is described in this article.
Abstract: The synthesis of 4-thio-D-galactofuranose (15) and derivatives, starting from methyl a-D-glucopyranoside (l), is described Esterification of 1 with N-benzoylimidazole afforded regioselectively methyl 2,3,6-tri-O-benzoyla-D-glucopyranoside (2c) Further sulfonylation of HO-4 of 2c gave methyl 2,3,6-tri-O-benzoyl-4-O-(p-tolylsulfonyl)-a-Dglucopyranoside (2e) or methyl 2,3,6-tri-O-benzoy1-4-0[ (p-bromophenyl)sulfonyl]-a-~glucopyanoside (2f) Nucleophilic substitution of the sulfonyloxy group by thiocyanate led to methyl 2,3,6-tri-O-benzoyl-4deoxy-4-thiocyano-a-~-galactopyranoside (3) This reaction allowed the simultaneous introduction of a group precursor of thiol and the inversion of the configuration a t C-4 Compound 3 was reduced to methyl 4-Sacetyl-2,3,6-tri-0-benzoyl-4-thio-a-~-galactopyranoside (4a) or methyl 2,3,6-tri-0-benzoyl-4-thio-a-~-galactopyranoside (4b) The latter was debenzoylated to give methyl 4-thio-a-~-galactopyranoside (5) This product was also obtained by alkaline methanolysis of 3 Ring contraction was achieved by acetolysis of 5, which produced 1,2,3,5,6-penta-0-acetyl-4-thio-a-~-galactofuranose (10)and its /3-anomer (11) as the main products The product distribution in the acetolysis reaction of 4-thiopyranose derivatives would depend on the stability of the ionic intermediates involved 0-Deacetylation of 10 led to 4-thio-~-galactofuranose (15)
TL;DR: The results obtained for the determination of iron(III) using the described procedure and the thiocyanate method were compared statistically by means of the Student t-test and no significant difference was found.
Abstract: The complexation of iron(III) with norfloxacin in acidic solution at 25 °C, at an ionic strength of about 0.3 M and a pH of 3.0 has been studied. The water-soluble complex formed, which exhibits an absorption maximum at 377 nm, was used for the spectrophotometric determination of trace amounts of iron(III). The molar absorptivity was 9.05 × 103 l mol–1 cm–1 and the Sandell sensitivity 6.2 ng cm–2 of iron(III) per 0.001 A. The formation constant (Kf) was determined spectrophotometrically and was found to be 4.0 × 108 at 25 °C. The calibration graph was rectilinear over the range 0.25–12.0 p.p.m. of iron(III) and the regression line equation was A= 0.163c– 0.00042 with a correlation coefficient of 0.9998 (n= 9). Common cations, except cerium(IV), did not interfere with the determination. The results obtained for the determination of iron(III) using the described procedure and the thiocyanate method were compared statistically by means of the Student t-test and no significant difference was found.
TL;DR: It was found that the presence of cyanide and resorcinol did not have any effect on the binding of thiocyanate, indicating that the binding site of the thiOCyanate ion is located away from the ferric center as well as from the aromatic donor binding site.
TL;DR: In this paper, the structural distortion due to steric hindrances has been detected in orthopalladated complexes of the type: Pd2(μ-Y)2(C10H21OC6H4C(CH3)NC6h4C6 h4R)2.
TL;DR: In this paper, the title complexes have been synthesized and their crystal and molecular structures determined by a single crystal X-ray diffraction technique, and they have been shown to be orthorhombic with a space group of A21am; a=10.773(2), b=16.574(4), c=9.542(5), and Z=2.94(4)°.
Abstract: The title complexes have been synthesized and their crystal and molecular structures determined by a single crystal X-ray diffraction technique. [(C2H5)4N][Cd(SCN)3] (1) is orthorhombic with a space group of A21am; a=10.773(2), b=16.574(4), c=9.871(2) A, and Z=4, while [(C3H7)4N][Cd(SCN)3] (2) is triclinic with a space group of P\bar1; a=10.297(5), b=11.542(5), c=9.374(3) A, α=90.10(3), β=91.61(4), γ=80.94(4)°, and Z=2. In 1, the metal atom has a 3N,3S-hexa-coordinated octahedral geometry, and three ligated N atoms take fac-configuration. Each pair of a metal atoms are bridged by three thiocyanate (SCN) ions, where two SCN ions are S-coordinated, while the other is N-coordinated to the same side metal atom, forming a linear polymeric form. In 2, the metal atom is in a 3N,2S-penta-coordinated trigonal-bipyramidal geometry, where one non-bridging SCN ion is N-coordinated equatorially, while four bridging SCN ions are ligated with two N (axially), and two S atoms (equatorially), respectively. Each pair of me...
TL;DR: In this article, the kinetics of the reaction between NCS− and the diprotonated forms of [ReO2(CN)4]3− have been studied in the ca. 1 to 3 pH range.
Abstract: The kinetics of the reaction between NCS− and the diprotonated forms of [ReO2(CN)4]3− have been studied in theca. 1 to 3 pH range. This study showed that the diprotonated form [ReO(OH2)(CN)4]−1 is the only reactive species and that only the aqua ligand is substituted by the thiocyanate ions according to the following reaction:
$$[ReO(OH_2 )(CN)_4 ]^{1 - } + NCS - [\operatorname{Re} O(NCS)(CN)_4 ]^{2 - } + H_2 O$$
The k1 and k−1 values are 3.48(4)×10−3 M−1 s−1 and −3(2)×10−5 s−1 respectively at 25°C. A dissociative activated substitution process is proposed.
TL;DR: The lactoperoxidase system had a strong bactericidal effect against C. jejuni and C. coli and decreased with decreasing pH-values.
TL;DR: In this paper, the reaction between copper(I) thiocyanate and imidazolidine-2-thione (imdtH2)2(NCS) has been characterised by a combination of spectroscopic thermal and crystal structure analysis.
TL;DR: In this paper, a rapid spectrophotometric flow-injection method is described for the determination of cyanide and thiocyanate, which involves a two-step procedure in which the total concentration of both species is first determined (using sodium isonicotinate/sodium barbiturate reagents), after which the cyanide is complexed with nickel(II) and thio-yanate is quantified separately; the concentration is calculated by difference.
TL;DR: The crystal and molecular structure of [Cu(paphy)(NCS)(SCN) has been determined from three-dimensional X-ray data in this paper, where the two copper(II) ions are linked in an unusual way through the N end of two N-thiocyanate bridging groups.
Abstract: The crystal and molecular structure of [Cu(paphy)(NCS)(SCN)](paphy = pyridine-2-carbaldehyde 2′-pyridylhydrazone) has been determined from three-dimensional X-ray data. It crystallizes in the monoclinic space group P21/a with four formula units in a cell of dimensions a= 15.778(3), b= 9.937(2), c= 9.795(3)A, and β= 91.31(2)°. Least-squares refinement of 1 163 reflections with I 2.5σ(I) gave a final R= 0.073 (R′= 0.073). The structure consists of isolated centrosymmetric [Cu(paphy)(NCS)(SCN)]2 dimeric units where the two copper(II) ions are linked in an unusual way through the N end of two N-thiocyanate bridging groups. The resulting co-ordination geometry around each copper(II) ion is elongated tetragonal octahedral. The N bridging atoms occupy simultaneously an equatorial position in the co-ordination sphere of one of the copper atoms and an axial one in the other. The remaining axial positions are occupied by sulphur atoms of the S-bonded thiocyanate groups. Magnetic susceptibility measurements down to 2.8 K and e.s.r. spectra provide evidence of the existence of very weak exchange coupling. These results are discussed on the basis of the structural features. A comparison is made with previously published data on related copper(II) thiocyanate complexes.
TL;DR: In this paper, the thermodynamics of the formation of gold(I) halide and thiocyanate complexes in pyridine and acetonitrile has been studied by means of potentiometric and calorimetric measurements at 25{degree}C. All solutions contained 0.1 M tetraethylammonium ions; perchlorate was used as a supplementary anion.
Abstract: The thermodynamics of the formation of gold(I) halide and thiocyanate complexes in pyridine and acetonitrile has been studied by means of potentiometric and calorimetric measurements at 25{degree}C. All solutions contained 0.1 M tetraethylammonium ions; perchlorate was used as a supplementary anion. Changes of free energies, enthalpies, and entropies could be determined for the two mononuclear complexes formed in each system, except for the iodide and thiocyanate complexes in acetonitrile, where only the formation of the second complex could be studied. The solubility was too low for the neutral thiocyanate complex, and gold(I) was reduced when the iodide/gold ratio was <2. The complexes are much less stable in pyridine than in acetonitrile, certainly due to the stronger solvation of Au{sup +} in the former solvent. The formation reactions are characterized by very large entropy gains. An analogous lowering of the coordination number therefore most probably takes place in the case of gold(I), in spite of the fact that the crystallized solvates are two-coordinated. Structural studies of gold(I) solutions by means of the EXAFS technique have fully confirmed this inference for both solvents. The Au-N distances are 2.16 and 2.19 {angstrom} in pyridine and acetonitrile, respectively, which is about 0.2 {angstrom} longermore » than in the corresponding two-coordinated solid solvates. Similar differences in metal-ligand distance are found between two- and four-coordinated complexes of other d{sup 10} acceptors, not only for the monovalent copper(I) and silver(I) but also for the divalent mercury(II). In pyridine and acetonitrile solutions, gold(I) thus certainly exists as a tetrahedral solvate. 50 refs., 7 figs., 5 tabs.« less
TL;DR: Practical methods for the quantitative measurement of cyanide and thiocyanate content in small biological samples are presented and precautions include a provision for sequestering cyanide in storage, the use of an antioxidant, and an avoidance of the spontaneous sulfide formation from proteins that occurs in even mildly alkaline solutions.