Presence Of Sodium Cyanide Research Articles

Anodic Cyanation of β-Dicarbonyl Compounds

Several β-dicarbonyl compounds were electrochemically oxidized in a methanolic solution in the presence of sodium cyanide and sodium methoxide to yield the corresponding α-cyano-β-dicarbonyl compounds in moderate to good yields. Presumably, a two-electron transfer transforms the anion derived from the β-dicarbonyl compounds into a cation, which then reacts with a cyanide ion to afford the cyanation products.

Reaction of d-pseudoephedrine hydrochloride with anisaldehyde in the presence of sodium cyanide

2-(p-Methoxyphenyl)-3,4-dimethyl-5-phenyl-1,3-oxadiazolidine was synthesized, and its steric structure was studied by X-ray diffraction.

Inhibition of tubulin assembly and covalent binding to microtubular protein by valproic acid glucuronide in vitro

Acyl glucuronides are reactive metabolites of carboxylate drugs, able to undergo a number of reactions in vitro and in vivo, including isomerization via intramolecular rearrangement and covalent adduct formation with proteins. The intrinsic reactivity of a particular acyl glucuronide depends upon the chemical makeup of the drug moiety. The least reactive acyl glucuronide yet reported is valproic acid acyl glucuronide (VPA-G), which is the major metabolite of the antiepileptic agent valproic acid (VPA). In this study, we showed that both VPA-G and its rearrangement isomers ( iso-VPA-G) interacted with bovine brain microtubular protein (MTP, comprised of 85% tubulin and 15% microtubule associated proteins {MAPs}). MTP was incubated with VPA, VPA-G and iso-VPA-G for 2 h at room temperature and pH 7.5 at various concentrations up to 4 mM. VPA-G and iso-VPA-G caused dose-dependent inhibition of assembly of MTP into microtubules, with 50% inhibition (IC 50) values of 1.0 and 0.2 mM respectively, suggesting that iso-VPA-G has five times more inhibitory potential than VPA-G. VPA itself did not inhibit microtubule formation except at very high concentrations (≥2 mM). Dialysis to remove unbound VPA-G and iso-VPA-G (prior to the assembly assay) diminished inhibition while not removing it. Comparison of covalent binding of VPA-G and iso-VPA-G (using [ 14C]-labelled species) showed that adduct formation was much greater for iso-VPA-G. When [ 14C]- iso-VPA-G was reacted with MTP in the presence of sodium cyanide (to stabilize glycation adducts), subsequent separation into tubulin and MAPs fractions by ion exchange chromatography revealed that 78 and 22% of the covalent binding occurred with the MAPs and tubulin fractions respectively. These experiments support the notion of both covalent and reversible binding playing parts in the inhibition of microtubule formation from MTP (though the acyl glucuronide of VPA is less important than its rearrangement isomers in this regard), and that both tubulin and (perhaps more importantly) MAPs form adducts with acyl glucuronides.

Formal Asymmetric Synthesis of Pentalenolactone E and Pentalenolactone F-2. Construction of the Angular Diquinanoid δ-Lactone

A formal asymmetric synthesis of pentalenolactone E (1b) and pentalenolactone F (1a) has been accomplished. Ozonolysis of the diphenyl-substituted triquinane 3 and Kauffmann methylenation of ketone 5 with WOCl3-2 MeLi yielded the unsubstituted triquinane 9. The crucial rearrangement of the linear triquinanoid lactone 11 to the angular triquinanoid lactone 14a was accomplished using orthoformate and acid in methanol. Subjecting triquinanes 14a/b to the selenoxide method gave triquinene 15. Homologation of γ-lactone 15 to the angular diquinanoid δ-lactone 2 via a Horner-Wadsworth-Emmons or Peterson reaction of hemiacetals 16a/b was, however, not successful. Chemoselective reduction of 14a afforded hemiacetals 21a/b, reaction of which with the phosphonate salt 17a ultimately led to the ketene dithioacetal 22. The angular intermediates 25a/b were obtained from 22 by reduction to give the linear hemiacetals 24a/b, which rearranged to the dithio ortholactones 25a/b in the presence of acid. Introduction of the double bond and deprotection were accomplished via selenation of 25a/b with N,N-diethylbenzeneselenylamide and treatment of selenides 30a/b with silver nitrate. The unsaturated aldehydes 28 and 29 thus obtained were converted to 2 and 31, respectively, by oxidation with manganese dioxide in the presence of sodium cyanide, methanol and acetic acid. Alkene 2 was isolated by crystallization.

Cell-free extract(s) of Pseudomonas putida catalyzes the conversion of cyanides, cyanates, thiocyanates, formamide, and cyanide-containing mine waters into ammonia.

Our isolate, Pseudomonas putida, is known to be capable of utilizing cyanides as the sole source of carbon (C) and nitrogen (N) both in the form of free cells and cells immobilized in calcium alginate. In the present study, the cell-free extract(s) were prepared from the cells of P. putida grown in the presence of sodium cyanide. The ability of enzyme(s) to convert cyanides, cyanates, thiocyanates, formamide and cyanide-containing mine waters into ammonia (NH3) was studied at pH 7.5 and pH 9.5. The kinetic analysis of cyanide and formamide conversion into NH3 at pH 7.5 and pH 9.5 by the cell-free extract(s) of P. putida was also studied. The Km and Vmax values for cyanide/formamide were found to be 4.3/8 mM and 142/227 mumol NH3 released mg protein-1 min-1 respectively at pH 7.5 and 5/16.67 mM and 181/434 mumol NH3 released mg protein-1 h-1 respectively at pH 9.5. The study thus concludes that the cell-free extract(s) of P. putida is able to metabolize not only cyanides, cyanates, thiocyanates, and formamide but also cyanide-containing mine waters to NH3.

Carbon‐11 labelled analogs of alanine by the strecker synthesis

AbstractDerivatives of alanine, α‐[2‐11C]aminoisobutyric acid 1a and α‐(N‐methyl)‐[2‐11C]aminoisobutyric acid 1b were prepared for the in‐vivo study of amino acid transport phenomena by positron‐emission‐tomography (PET). Compounds 1a and 1b were obtained by a Zelinski‐Stadnikoff variant of the Strecker α‐amino acid synthesis from in‐situ formed [11C]acetone in presence of sodium cyanide and either ammonium sulfate (for 1a) or methylamine hydrochloride (for 1b). The complete preparation required 50 min from the end of [11C]CO2 production, and delivered 1.2 ‐ 2 GBq of labelled product for application (2.4 ‐ 4%; not corrected for decay; related to trapped [11C]CO2). The specific activity of the labelled products was 16 to 20 GBq·μmol−1. The radiochemical and chemical purity of the preparations was greater than 98%.

ChemInform Abstract: Electrochemical Oxidation of Ketone Acylhydrazones and Their HCN Adducts in NaCN‐MeOH. Transformation of Ketones to Nitriles.

AbstractEleven acylhydrazones such as (I) are converted into nitriles such as (III) by electrolysis in the presence of sodium cyanide (II).

The mechanism of copper leaching by intact cells of Thiobacillus ferrooxidans.

Under aerobic conditions, washed intact cells of Thiobacillus ferrooxidans AP19-3 solubilized copper enzymatically from a copper concentrate containing Cu(20.48%), Fe(31.61%), 8(38.22%), Pb(3.84%), and Zn(4.22%). The optimum pH of copper solubilization from copper concentrate was at pH 3.0. In contrast, under anaerobic conditions or under aerobic conditions in the presence of sodium cyanide, inhibitor of iron oxidase, the amount of copper solubilized enzymatically from the ore markedly decreased, indicating that iron oxidase is involved in the copper solubilization. Under the conditions under which iron oxidase of the cells cannot operate, Fe2+ and Cu+ ions were produced enzymatically, suggesting that a hydrogen sulfide: ferric ion oxidoreductase (SFORase) was involved in this copper solubilization from the ore. A short treatment of the strain with 0.5% phenol completely destroyed the SFORase. However, this treatment did not affect the iron oxidase of the cells. A concomitant loss of the activity of copper solubilization from the ore was observed in 0.5% phenol-treated cells. The results strongly suggest that both iron oxidase and SFORase are crucial in copper ore leaching by T. ferrooxidans AP19-3.

ChemInform Abstract: Synthesis of 2,4,5‐Trisubstituted Oxazoles and a Study of Their Fluorescent Properties.

AbstractBenzoyl chloride (II) reacts with equimolar amounts of benzaldehyde (I) in the presence of sodium cyanide (III) to give the intermediate O‐benzoylarylcyanohydrin (IV) which is treated with a further equimolar amount of benzaldehyde (I), yielding the benzoyloxybenzyl phenyl ketone (V).

Effects of reduced oxygen tension on endothelium-dependent relaxation induced by acetylcholine differ in rabbit femoral artery and jugular vein.

In intact rabbit femoral artery rings pre-contracted with phenylephrine, acetylcholine (ACh; 10(-9)-10(-6) M) produces endothelium-dependent relaxation, abolished after mechanical rubbing to remove the endothelium. The response to ACh was absent at low oxygen tension (less than or equal to 4 kPa) or in the presence of sodium cyanide (1 mM). Intact rabbit jugular veins relaxed to ACh in lower concentration than did the femoral artery, 10(-10)-10(-8) M; at sufficient ACh concentration the relaxation was complete. In veins with completely removed endothelium no relaxation to ACh occurred, and at concentrations above 3 x 10(-7) M the response was a contraction. The relaxation response to ACh of intact veins persisted during contraction at lower oxygen tension or in the presence of 1 mM sodium cyanide. In rubbed veins, cyanide consistently induced a transient contraction, which was absent in intact veins. The study demonstrates pronounced endothelium-dependent relaxation to ACh in a venous preparation, with a markedly lower sensitivity of the relaxation response to hypoxia than in a muscular artery of the same species.

Active-site modification of mammalian pyruvate dehydrogenase by pyridoxal 5'-phosphate.

The pyruvate dehydrogenase multienzyme complex from bovine kidney and heart is inactivated by treatment with pyridoxal 5'-phosphate and sodium cyanide or sodium borohydride. The site of this inhibition is the pyruvate dehydrogenase (E1) component of the complex. Inactivation of E1 by the pyridoxal phosphate-cyanide treatment was prevented by thiamin pyrophosphate. Equilibrium binding studies showed that E1 contains two thiamin pyrophosphate binding sites per molecule (alpha 2 beta 2) and that modification of E1 increased the dissociation constant (Kd) for thiamin pyrophosphate about 5-fold. Incorporation of approximately 2.4 equiv of 14CN per mole of E1 tetramer in the presence of pyridoxal phosphate resulted in about a 90% loss of E1 activity. Radioactivity was incorporated predominantly into the E1 alpha subunit. Radioactive N6-pyridoxyllysine was identified in an acid hydrolysate of the E1-pyridoxal phosphate complex that had been reduced with NaB3H4. The data are interpreted to indicate that in the presence of sodium cyanide or sodium borohydride, pyridoxal phosphate reacts with a lysine residue at or near the thiamin pyrophosphate binding site of E1. This binding site is apparently located on the alpha subunit.

ChemInform Abstract: ELECTROOXIDATIVE CONVERSION OF ALDEHYDES INTO METHYL CARBOXYLATES

The electrolytic oxidation of methanolic solutions of aldehydes in the presence of sodium cyanide at a platinum anode was found to produce corresponding methyl carboxylates.

Assimilation of ?-butyrobetaine, and d-and l-carnitine by resting cell suspensions of Acinetobacter calcoaceticus and Pseudomonas putida

The metabolic pattern of utilization of [1,2,3,4-14C, methyl-3H] γ-butyrobetaine and d-and l-[1-14C, methyl-3H]carnitine has been examined with variously grown resting cell suspensions of Acinetobacter calcoaceticus and Pseudomonas putida. Ps. putida grown on d, l-carnitine as the sole source of carbon, degraded only l-carnitine with stoichiometric accumulation of glycinebetaine. Alternatively, when grown on γ-butyrobetaine, Ps. putida rapidly metabolized γ-butyrobetaine, and to a lesser but significant extent, both d-and l-carnitine with equivalent formation of trimethylamine and degradation of the betaine carbon skeleton. Ac. calcoaceticus grown on either d,l-carnitine or γ-butyrobetaine, effectively utilized all three betaines at nearly the same rates. Disappearance of each of these quarternary ammonium compounds was accompanied by stoichiometric formation of trimethylamine and degradation of the carbon backbone. Utilization of the betaines and corresponding formation of trimethylamine by resting cell suspensions of appropriately grown Ac. calcoaceticus and Ps. putida, was essentially abolished under conditions of anaerobiosis and severely impaired in the presence of sodium cyanide, sodium azide, 2,4-dinitrophenol or 2,2′-bipyridine. The results of the present investigations with resting cell suspensions of both Ac. calcoaceticus and Ps. putida do not support an earlier suggestion that γ-butyrobetaine degradation in these organisms proceeds by its prior hydroxylation to l-carnitine. Indeed, disrupted cell-free preparations of Ac. calcoaceticus and Ps. putida grown on either d,l-carnitine or γ-butyrobetaine showed no detectable γ-butyrobetaine hydroxylase activity.

Electrooxidative Conversion of Aldehydes into Methyl Carboxylates

Abstract The electrolytic oxidation of methanolic solutions of aldehydes in the presence of sodium cyanide at a platinum anode was found to produce corresponding methyl carboxylates.

Effect of metabolic inhibitors and ouabain on amphetamine- and potassium-induced release of biogenic amines from isolated brain tissue

In experiments on isolated rat cerebral cortex, it was observed that d-amphetamine released norepinephrine from cerebral cortex into the incubation medium. Amphetamine-induced release of norepinephrine was markedly potentiated in the presence of the metabolic inhibitors sodium cyanide, 2,4-dinitrophenol and iodoacetate. Release of norepinephrine by the metabolic inhibitors in the absence of amphetamine was minimal. Amphetamine-induced release of dopamine from corpus striatum was also potentiated by sodium cyanide. The EC 50 for amphetamine-induced release of dopamine was 20μM with amphetamine alone and 0.58 μM in the presence of sodium cyanide. Release of norepinephrine and dopamine by elevated concentrations of potassium chloride was again potentiated by the metabolic inhibitors. Similarly, ouabain (10–25 μM) produced minimal release of norepinephrine but potentiated amphetamine- and potassium-induced release of catecholamines. The metabolic inhibitors markedly reduced the ATP content of the chopped tissue during the incubation while ouabain had no effect. The results suggest that the potentiation of amphetamine- and potassium-induced release of biogenic amines from isolated brain tissue is not simply due to depletion of tissue ATP levels but may be related to sodium or potassium transport. The Na + , K + -ATPase sodium pump is inhibited either: (1) when ATP levels are reduced by metabolic inhibitors, or (2) when Na + , K + -ATPase is inhibited by ouabain. Inhibition of the sodium pump would lead to an increase in the intraneuronal sodium concentration. A model is described in which norepinephrine and sodium are co-transported across the membrane during amphetamine-induced release of the biogenic amine. Elevation of the intraneuronal sodium concentration would provide increased levels of the co-substrate for transport and could account for the potentiation of release produced by metabolic inhibitors and ouabain.

Absence of ultrafast processes of repair of single-strand breaks in mammalian DNA.

Town, Smith and Kaplan (1972) reported that the yield of DNA single-strand breaks (SSB) in E. coli is largely independent of the presence of molecular oxygen during irradiation. They suggested that the oxygen enhancement ratio (o.e.r.) normally observed is due to the presence of an ultrafast repair mechanism acting (in bacterial cells) mainly on anoxically-produced breaks. To determine whether similar mechanisms exist in mammalian cells, we carried out comparable experiments on two cell-lines, one from Chinese hamster, the other from mouse. Both heat inactivation and chemical inhibition were treatment inactivated all the enzymatic processes assayed, it did not alter the o.e.r. for SSB production, which remained about 3-0. The presence of sodium cyanide, hydroxyurea, iodoacetic acid, EDTA and quinacrine all failed to alter significantly the o.e.r. Isolated nuclei also demonstrated the full o.e.r. For these cell-lines at least, ultrafast reprir does not seem to exist. Isolated Adenovirus 2, which presumably lacks enzymic activity, demonstrated an o.e.r. of 3-6 for SSB production. From these results and others it seems unlikely that the so-called ultrafast enzymic repair is a general phenomenon accounting for the o.e.r. in a wide range of biological systems. Rather, the o.e.r. for SSB seems to result from differences in the direct physico-chemical effects of radiation under aerobic and anoxic conditions in most organisms.

Constriction of human umbilical vein under aerobic and anaerobic conditions.

In the presence of metabolic inhibitors, the responses to serotonin of helically cut strips of human umbilical vein in Krebs–Henseleit solution at 37 °C were recorded isotonically. The tissues contracted to serotonin in a 95% nitrogen – 5% carbon dioxide atmosphere and in the presence of sodium cyanide (NaCN, 10−3M) and 2,4-dinitrophenol (DNP, 10−3M). The results indicate that human umbilical vein is capable of responding quite well to serotonin at very low oxygen levels and in the presence of sodium cyanide. The average maximum contractions to serotonin in the presence of NaCN and in the 95% nitrogen – 5% carbon dioxide atmosphere were, respectively, 91% and 88% of control. The contractile responses to serotonin were quite inhibited in the presence of 2,4-dinitrophenol. The combination of NaCN plus DNP did not inhibit the contractions to serotonin over that inhibited by DNP alone.

Studies on Acyl Alkyl Diimides

A number of acyclic acyl alkyl diimides have been obtained by oxidation of the corresponding alkyl hydrazides. A new method for the synthesis of α-cyanoalkyl hydrazides, the reaction of acid hydrazides with ketones in the presence of sodium cyanide, has been explored. All the acyl alkyl diimides so obtained exhibit a medium to weak i.r. band at ca. 1550 cm−1; evidence supporting the assignment of this band to the —N=N— stretch is given. The results of oxidation of 5-methyl and 5-phenyl-pyrazolidin-3-one are reported, together with the synthesis and oxidation of tetrahydro-6-methyl-3(2H)-pyridazinone.

Properties of the Hemolytic Activities of Escherichia coli

Some properties of the cell-free and cell-associated hemolysins of Escherichia coli were studied. Several strains of E. coli that were isolated from intestines of pigs with edema disease produce large quantities of cell-free hemolysin when grown in the presence of an extract of meat. The component of meat that stimulates production of cell-free hemolysin is not extracted by lipid solvents and is not dialyzable. The cell-free hemolysin is an acidic substance that occurs in two forms. It is inactivated by trypsin but not by lecithinase, lysozyme, ribonuclease, or deoxyribonuclease, shows optimum activity between pH 7 and 8, and requires calcium ion for activity. It does not appear to be an enzyme. The kinetics of the lytic reaction are most consistent with the hypothesis that one molecule of cell-free hemolysin is sufficient to lyse one erythrocyte and that it is inactivated in the lytic reaction. The cell-free hemolysin does not sufficiently damage the cell during the prelytic period to cause lysis after the hemolysin-calcium-erythrocyte complex has been disrupted. The cell-associated hemolysin was not separated from the cell by autolysis, freezing, sonic treatment, or treatment with trypsin or lysozyme. It appears to be closely associated with the metabolic status of the cell. Organisms that are highly hemolytic under usual conditions of assay immediately lose most of their hemolytic capability in the presence of sodium cyanide, streptomycin, nalidixic acid, and rifampin.

The preparation of carboxylic amides from aldehydes by oxidation

The oxidation of aromatic and αβ-unsaturated aldehydes with maganese dioxide in the presence of sodium cyanide and an amine leads to high yields of the corresponding carboxylic amides.