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Nuclear Medicine and Biology 2021Hydrogen cyanide (HCN) is a versatile synthon for generating carbon‑carbon and carbon-heteroatom bonds. Unlike other one-carbon synthons (i.e., CO, CO), HCN can... (Review)
Review
Hydrogen cyanide (HCN) is a versatile synthon for generating carbon‑carbon and carbon-heteroatom bonds. Unlike other one-carbon synthons (i.e., CO, CO), HCN can function as a nucleophile (as in potassium cyanide, KCN) and an electrophile (as in cyanogen bromide, (CN)Br). The incorporation of the CN motif into organic molecules generates nitriles, hydantoins and (thio)cyanates, which can be converted to carboxylic acids, aldehydes, amides and amines. Such versatile chemistry is particularly attractive in PET radiochemistry where diverse bioactive small molecules incorporating carbon-11 in different positions need to be produced. The first examples of making [C]HCN for radiolabeling date back to the 1960s. During the ensuing decades, [C]cyanide labeling was popular for producing biologically important molecules including C-labeled α-amino acids, sugars and neurotransmitters. [C]cyanation is now reemerging in many PET centers due to its versatility for making novel tracers. Here, we summarize the chemistry of [C]HCN, review the methods to make [C]HCN past and present, describe methods for labeling different types of molecules with [C]HCN, and provide an overview of the reactions available to convert nitriles into other functional groups. Finally, we discuss some of the challenges and opportunities in [C]HCN labeling such as developing more robust methods to produce [C]HCN and developing rapid and selective methods to convert nitriles into other functional groups in complex molecules.
Topics: Positron-Emission Tomography
PubMed: 34624831
DOI: 10.1016/j.nucmedbio.2021.09.002 -
The Journal of General and Applied... Sep 2016Cyanide is known as a toxic compound for almost all living organisms. We have searched for cyanide-resistant bacteria from the soil and stock culture collection of our...
Cyanide is known as a toxic compound for almost all living organisms. We have searched for cyanide-resistant bacteria from the soil and stock culture collection of our laboratory, and have found the existence of a lot of microorganisms grown on culture media containing 10 mM potassium cyanide. Almost all of these cyanide-resistant bacteria were found to show β-cyano-L-alanine (β-CNAla) synthetic activity. β-CNAla synthase is known to catalyze nitrile synthesis: the formation of β-CNAla from potassium cyanide and O-acetyl-L-serine or L-cysteine. We found that some microorganisms were able to detoxify cyanide using O-methyl-DL-serine, O-phospho-L-serine and β-chloro-DL-alanine. In addition, we purified β-CNAla synthase from Pseudomonas ovalis No. 111 in nine steps, and characterized the purified enzyme. This enzyme has a molecular mass of 60,000 and appears to consist of two identical subunits. The purified enzyme exhibits a maximum activity at pH 8.5-9.0 at an optimal temperature of 40-50°C. The enzyme is specific for O-acetyl-L-serine and β-chloro-DL-alanine. The Km value for O-acetyl-L-serine is 10.0 mM and Vmax value is 3.57 μmol/min/mg.
Topics: Alanine; Culture Media; Cyanides; Cysteine; Hydrogen-Ion Concentration; Kinetics; Lyases; Molecular Weight; Nitriles; Pseudomonas; Serine; Serine O-Acetyltransferase; Substrate Specificity; Temperature
PubMed: 27250663
DOI: 10.2323/jgam.2016.02.003 -
New Zealand Veterinary Journal Jun 2015Tuberculosis (TB) due to Mycobacterium bovis infection was first identified in brushtail possums (Trichosurus vulpecula) in New Zealand in the late 1960s. Since the... (Review)
Review
Tuberculosis (TB) due to Mycobacterium bovis infection was first identified in brushtail possums (Trichosurus vulpecula) in New Zealand in the late 1960s. Since the early 1970s, possums in New Zealand have been controlled as part of an ongoing strategy to manage the disease in livestock. The TB management authority (TBfree New Zealand) currently implements three strategic choices for disease-related possum control: firstly TB eradication in areas selected for eradication of the disease from livestock and wildlife, secondly Free Area Protection in areas in which possums are maintained at low densities, normally along a Vector Risk Area (VRA) boundary, and thirdly Infected Herd Suppression, which includes the remaining parts of VRA where possums are targeted to minimise the infection risk to livestock. Management is primarily through a range of lethal control options. The frequency and intensity of control is driven by a requirement to reduce populations to very low levels (usually to a trap-catch index below 2%), then to hold them at or below this level for 5-10 years to ensure disease eradication.Lethal possum control is implemented using aerial- and ground-based applications, under various regulatory and operational constraints. Extensive research has been undertaken aimed at improving the efficacy and efficiency of control. Aerial applications use sodium fluoroacetate (1080) bait for controlling possums over extensive and rugged areas of forest that are difficult to access by foot. Ground-based control uses a range of toxins (primarily, a potassium cyanide-based product) and traps. In the last 5 years there has been a shift from simple possum population control to the collection of spatial data on possum presence/absence and relative density, using simple possum detection devices using global positioning system-supported data collection tools, with recovery of possum carcasses for diagnostic necropsy. Such data provide information subsequently used in predictive epidemiological models to generate a probability of TB freedom.The strategies for managing TB in New Zealand wildlife now operate on four major principles: firstly a target threshold for possum population reduction is defined and set, secondly an objective methodology is applied for assessing whether target reductions have been achieved, thirdly effective control tools for achieving possum population reductions are used, and fourthly the necessary legislative support is in place to ensure compliance. TBfree New Zealand's possum control programme meets these requirements, providing an excellent example of an effective pest and disease control programme.
Topics: Animals; Introduced Species; Mycobacterium bovis; New Zealand; Population Surveillance; Trichosurus; Tuberculosis
PubMed: 25582863
DOI: 10.1080/00480169.2014.981315 -
Current Research in Microbial Sciences 2022Modern intensive agricultural practices face numerous challenges that pose major threats to global food security. In order to address the nutritional requirements of the... (Review)
Review
Modern intensive agricultural practices face numerous challenges that pose major threats to global food security. In order to address the nutritional requirements of the ever-increasing world population, chemical fertilizers and pesticides are applied on large scale to increase crop production. However, the injudicious use of agrochemicals has resulted in environmental pollution leading to public health hazards. Moreover, agriculture soils are continuously losing their quality and physical properties as well as their chemical (imbalance of nutrients) and biological health. Plant-associated microbes with their plant growth- promoting traits have enormous potential to solve these challenges and play a crucial role in enhancing plant biomass and crop yield. The beneficial mechanisms of plant growth improvement include enhanced nutrient availability, phytohormone modulation, biocontrol of phytopathogens and amelioration of biotic and abiotic stresses. Solid-based or liquid bioinoculant formulation comprises inoculum preparation, addition of cell protectants such as glycerol, lactose, starch, a good carrier material, proper packaging and best delivery methods. Recent developments of formulation include entrapment/microencapsulation, nano-immobilization of microbial bioinoculants and biofilm-based biofertilizers. This review critically examines the current state-of-art on use of microbial strains as biofertilizers and the important roles performed by these beneficial microbes in maintaining soil fertility and enhancing crop productivity.
PubMed: 35024641
DOI: 10.1016/j.crmicr.2021.100094 -
BMJ Case Reports Jul 2019While potassium cyanide poisoning has been well described, the toxicity of potassium gold cyanide is less well understood. This case describes an 84-year-old man who...
While potassium cyanide poisoning has been well described, the toxicity of potassium gold cyanide is less well understood. This case describes an 84-year-old man who presented after an intentional ingestion of 0.5-1 teaspoons of potassium gold cyanide. Despite antidotal therapy, the patient rapidly developed severe lactic acidosis, multiorgan dysfunction and ultimately expired. While the patient's clinical findings were consistent with acute cyanide poisoning, a serum cyanide level was below the toxic threshold. Previous reports have suggested that gold toxicity may also contribute to the effects of potassium gold cyanide, and may have played a role in the patient's rapid decline. In addition to treatment of cyanide toxicity, management of acute gold toxicity should also be considered in potassium gold cyanide ingestion.
Topics: Acidosis, Lactic; Aged, 80 and over; Cyanates; Gold; Gold Compounds; Humans; Male; Potassium Cyanide; Suicide
PubMed: 31350229
DOI: 10.1136/bcr-2019-229947 -
Anatomical Science International Jan 2016Bacterial β-galactosidase is one of the most widely used reporter genes in experiments involving transgenic and knockout animals. In this review we discuss the current... (Review)
Review
Bacterial β-galactosidase is one of the most widely used reporter genes in experiments involving transgenic and knockout animals. In this review we discuss the current histochemical methods and available reagents to detect β-galactosidase activity. Different substrates are available, but the most commonly used is X-gal in combination with potassium ferri- and ferro-cyanide. The reaction produces a characteristic blue precipitate in the cells expressing β-galactosidase, and despite its efficiency in staining whole embryos, its detection on thin tissue sections is difficult. Salmon-gal is another substrate, which in combination with ferric and ferrous ions gives a reddish-pink precipitate. Its sensitivity for staining tissue sections is similar to that of X-gal. Combining X-gal or Salmon-gal with tetrazolium salts provides a faster and more sensitive reaction than traditional β-galactosidase histochemistry. Here, we compare the traditional β-galactosidase assay and the combination of X-gal or Salmon-gal with three tetrazolium salts: nitroblue tetrazolium, tetranitroblue tetrazolium and iodonitrotetrazolium. Based on an assessment of the sensitivity and specificity of the different combinations of substrates, we are proposing an optimized and enhanced method for β-galactosidase detection in histological sections of the transgenic mouse brain. Optimal staining was obtained with X-gal in combination with nitroblue tetrazolium, which provides a faster and more specific staining than the traditional X-gal combination with potassium ferri- and ferro-cyanide. We recommend the X-gal/nitroblue tetrazolium staining mixture as the first choice for the detection of β-galactosidase activity on histological sections. When faster results are needed, Salmon-gal/nitroblue tetrazolium should be considered as an alternative, while maintaining acceptable levels of noise.
Topics: Animals; Brain; Ferricyanides; Ferrocyanides; Galactosides; Histocytochemistry; Indicators and Reagents; Indoles; Mice, Transgenic; Nitroblue Tetrazolium; beta-Galactosidase
PubMed: 26394634
DOI: 10.1007/s12565-015-0300-3 -
Food Technology and Biotechnology Dec 2016In this study, optimization conditions for cyanide biodegradation by strain were determined to be 25 °C, pH=7 and 150 rpm at the concentration of 0.5 mM potassium...
In this study, optimization conditions for cyanide biodegradation by strain were determined to be 25 °C, pH=7 and 150 rpm at the concentration of 0.5 mM potassium cyanide in the medium. Additionally, it was found that strain is not only able to degrade potassium cyanide, but also to degrade potassium hexacyanoferrate(II) trihydrate and sodium ferrocyanide decahydrate with the efficiencies of 85 and 87.5%, respectively. Furthermore, this strain degraded potassium cyanide in the presence of different ions such as magnesium, nickel, cobalt, iron, chromium, arsenic and zinc, in variable concentrations (0.1, 0.25 and 0.5 mM) and as a result the amount of the bacteria in the biodegradation media decreased with the increase of ion concentration. Lastly, it was also observed that sterile crude extract of strain degraded potassium cyanide on the fifth day of incubation. Based on these results, it is concluded that both culture and sterile crude extract of will be used in cyanide removal from different wastes.
PubMed: 28115902
DOI: 10.17113/ftb.54.04.16.4518 -
Toxicological Sciences : An Official... Jan 2023Cyanide-a fast-acting poison-is easy to obtain given its widespread use in manufacturing industries. It is a high-threat chemical agent that poses a risk of occupational...
Cyanide-a fast-acting poison-is easy to obtain given its widespread use in manufacturing industries. It is a high-threat chemical agent that poses a risk of occupational exposure in addition to being a terrorist agent. FDA-approved cyanide antidotes must be given intravenously, which is not practical in a mass casualty setting due to the time and skill required to obtain intravenous access. Glyoxylate is an endogenous metabolite that binds cyanide and reverses cyanide-induced redox imbalances independent of chelation. Efficacy and biochemical mechanistic studies in an FDA-approved preclinical animal model have not been reported. Therefore, in a swine model of cyanide poisoning, we evaluated the efficacy of intramuscular glyoxylate on clinical, metabolic, and biochemical endpoints. Animals were instrumented for continuous hemodynamic monitoring and infused with potassium cyanide. Following cyanide-induced apnea, saline control or glyoxylate was administered intramuscularly. Throughout the study, serial blood samples were collected for pharmacokinetic, metabolite, and biochemical studies, in addition, vital signs, hemodynamic parameters, and laboratory values were measured. Survival in glyoxylate-treated animals was 83% compared with 12% in saline-treated control animals (p < .01). Glyoxylate treatment improved physiological parameters including pulse oximetry, arterial oxygenation, respiration, and pH. In addition, levels of citric acid cycle metabolites returned to baseline levels by the end of the study. Moreover, glyoxylate exerted distinct effects on redox balance as compared with a cyanide-chelating countermeasure. In our preclinical swine model of lethal cyanide poisoning, intramuscular administration of the endogenous metabolite glyoxylate improved survival and clinical outcomes, and ameliorated the biochemical effects of cyanide.
Topics: Swine; Animals; Cyanides; Disease Models, Animal; Antidotes; Hemodynamics; Glyoxylates; Poisoning
PubMed: 36326479
DOI: 10.1093/toxsci/kfac116 -
Organic Letters Sep 2021A nickel-catalyzed cyanation of aryl thioethers using Zn(CN) as a cyanide source has been developed to access functionalized aryl nitriles. The ligand dcype...
A nickel-catalyzed cyanation of aryl thioethers using Zn(CN) as a cyanide source has been developed to access functionalized aryl nitriles. The ligand dcype (1,2-bis(dicyclohexylphosphino)ethane) in combination with the base KOAc (potassium acetate) is essential for achieving this transformation efficiently. This reaction involves both a C-S bond activation and a C-C bond formation. The scalability, low catalyst and reagents loadings, and high functional group tolerance have enabled both late-stage derivatization and polymer recycling, demonstrating the reaction's utility across organic chemistry.
PubMed: 34433260
DOI: 10.1021/acs.orglett.1c02285