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Chemosphere May 2022In spite of available information demonstrating the assimilation of cyanide (CN) by β-cyanoalanine synthase (β-CAS) in plants, involvement of sulfurtransferase (ST) in...
In spite of available information demonstrating the assimilation of cyanide (CN) by β-cyanoalanine synthase (β-CAS) in plants, involvement of sulfurtransferase (ST) in CN assimilation in rice plants is still undefined. In this study, a microcosmic hydroponic system was used to investigate the involvement of β-cyanoalanine synthase (β-CAS) and sulfurtransferase (ST) in the CN assimilation in rice seedlings under the exposure of potassium cyanide (KCN) in presence or absence of 1-amino-cyclopropane-1-carboxylic acid (ACC). Our results indicated that the measurable thiocyanate (SCN) was detected in both rice roots and shoots under KCN exposure, and the abundances of ST-related transcripts were up-regulated significantly (p < 0.05), suggesting that the ST pathway is involved in CN assimilation in the rice plants. The application of exogenous ACC significantly (p < 0.05) decreased the accumulation of CN and SCN in rice tissues after KCN exposures, and also up-regulated the expression of β-CAS and ST genes and their enzymatic activities, suggesting a positive interaction between aminocyclopropane-1-carboxylate oxidase (ACO), β-CAS and ST in rice plants during the CN assimilation. This is the first attempt to experimentally clarify the involvement of ST in CN assimilation in rice seedlings.
Topics: Cyanides; Lyases; Oryza; Seedlings; Sulfurtransferases
PubMed: 35101430
DOI: 10.1016/j.chemosphere.2022.133789 -
PeerJ 2021Rubber () is a perennial plant crop grown in many parts of Africa, South East Asia, and South America, especially within the hot and humid climatic regions. Rubber seed,...
Rubber () is a perennial plant crop grown in many parts of Africa, South East Asia, and South America, especially within the hot and humid climatic regions. Rubber seed, either as feed or food, is a useful raw material to produce edible oil and protein. Despite the huge quantity of rubber seeds produced in Nigeria and its potential as a protein source, rubber seeds still appear neglected and under-utilised as feed/food given its perception as inedible and toxic due to the high concentration of cyanogenic glycoside. Therefore, the quest for effective processing technique(s) that would enhance its food use application is very fitting. This current study was directed to determine the changes in anti-nutrient, phytochemical, and micronutrient contents of different processed rubber seed meals. Specifically, the rubber seeds underwent processing, which employed boiling and the combined action of boiling and fermentation methods that brought about three seed meal flour groups, i.e., raw (RRSM), boiled (BRSM), and fermented (FRSM) seed meals. These were subsequently analysed for anti-nutrient/phytochemical (oxalate, phytate, tannin, phenols, saponin, hydrogen cyanide (HCN), alkaloids, flavonoids, and trypsin inhibitors), and micronutrient (which involved minerals (magnesium, phosphorus, calcium, iron, zinc, potassium, sodium, manganese, lead, and selenium) and vitamin (vitamin B1, B2, B3, C, E, and beta carotene)) contents. The results showed that the processing methods used to achieve the RRSM, BRSM, and FRSM, reduced the anti-nutrients (phytate, tannin, and oxalate) below the acceptable limits, and the HCN below the toxic levels. Importantly, the processing methods herein have not yet succeeded in removing HCN in the (processed) rubber seed meals, but can be seen to be heading toward the right direction. The FRSM obtained significantly lower ( < 0.05) anti-nutrient/phytochemical, but significantly higher ( < 0.05) mineral contents, compared with the other groups (RRSM and BRSM), except for flavonoids that obtained a 30% increase over the BRSM. Some mineral and vitamin contents could be lost in the BRSM compared to the others (RRSM and FRSM) in this study. Additionally, the FRSM obtained higher vitamin contents, after those of RRSM. Overall, the combined action of boiling and fermentation should be recommended for the proper utilisation of rubber seed as food/feed.
PubMed: 34055479
DOI: 10.7717/peerj.11327 -
Journal of Forensic Sciences May 2021Hydrogen cyanide (HCN) can be a major contributory factor in death from fire-related inhalation injury. Although carbon monoxide (CO) is considered the lethal agent of...
Hydrogen cyanide (HCN) can be a major contributory factor in death from fire-related inhalation injury. Although carbon monoxide (CO) is considered the lethal agent of smoke in fires, its liability as a cause of death is sometimes debatable. The purpose of this report is to present the case of an 80-year-old man with locomotor disabilities who died due to an open space fire of vegetation debris and household waste in his yard. We evaluated here the concentrations of HCN and carboxyhemoglobin (COHb) and their contribution to the mechanism of death. In addition, the risk factors and the contributing effect of the factors that compose the complex toxic environment that develops in fires were discussed. COHb was determined by spectrophotometry as recommended by Katsumata et al. in 1982. HCN was determined with ninhydrin in postmortem blood samples after removal with 20% phosphoric acid and capture in a potassium carbonate solution. A toxic concentration of 1.3 μg ml HCN and a lethal COHb level of 73.7% were determined in the blood samples. Although death was mainly attributed to CO poisoning and extremely severe burns in this open space burning case, the additive effect of HCN in the mechanism of death was also highlighted. The results suggested the possibility that the man's clothing may have played an important role in the production of HCN in this open space fire, as well as other types of garbage that were burned.
Topics: Aged, 80 and over; Burns; Carbon Monoxide Poisoning; Carboxyhemoglobin; Fires; Forensic Medicine; Humans; Hydrogen Cyanide; Male; Mobility Limitation; Spectrophotometry
PubMed: 33369895
DOI: 10.1111/1556-4029.14649 -
BMC Biology Jul 2020Neuronal computations related to sensory and motor activity along with the maintenance of spike discharge, synaptic transmission, and associated housekeeping are...
BACKGROUND
Neuronal computations related to sensory and motor activity along with the maintenance of spike discharge, synaptic transmission, and associated housekeeping are energetically demanding. The most efficient metabolic process to provide large amounts of energy equivalents is oxidative phosphorylation and thus dependent on O consumption. Therefore, O levels in the brain are a critical parameter that influences neuronal function. Measurements of O consumption have been used to estimate the cost of neuronal activity; however, exploring these metabolic relationships in vivo and under defined experimental conditions has been limited by technical challenges.
RESULTS
We used isolated preparations of Xenopus laevis tadpoles to perform a quantitative analysis of O levels in the brain under in vivo-like conditions. We measured O concentrations in the hindbrain in relation to the spike discharge of the superior oblique eye muscle-innervating trochlear nerve as proxy for central nervous activity. In air-saturated bath Ringer solution, O levels in the fourth ventricle and adjacent, functionally intact hindbrain were close to zero. Inhibition of mitochondrial activity with potassium cyanide or fixation of the tissue with ethanol raised the ventricular O concentration to bath levels, indicating that the brain tissue consumed the available O. Gradually increasing oxygenation of the Ringer solution caused a concurrent increase of ventricular O concentrations. Blocking spike discharge with the local anesthetics tricaine methanesulfonate diminished the O consumption by ~ 50%, illustrating the substantial O amount related to neuronal activity. In contrast, episodes of spontaneous trochlear nerve spike bursts were accompanied by transient increases of the O consumption with parameters that correlated with burst magnitude and duration.
CONCLUSIONS
Controlled experimental manipulations of both the O level as well as the neuronal activity under in vivo-like conditions allowed to quantitatively relate spike discharge magnitudes in a particular neuronal circuitry with the O consumption in this area. Moreover, the possibility to distinctly manipulate various functional parameters will yield more insight in the coupling between metabolic and neuronal activity. Thus, apart from providing quantitative empiric evidence for the link between physiologically relevant spontaneous spike discharge in the brain and O-dependent metabolism, isolated amphibian preparations are promising model systems to further dissociate the O dynamics in relation to neuronal computations.
Topics: Animals; Brain; Larva; Neurons; Oxygen; Oxygen Consumption; Xenopus laevis
PubMed: 32615976
DOI: 10.1186/s12915-020-00811-6 -
Toxics Feb 2021Carbon monoxide (CO) and hydrogen cyanide (HCN) are two common toxic products of combustion. HCN concentrations of fire victims are not routinely determined in most...
Carbon monoxide (CO) and hydrogen cyanide (HCN) are two common toxic products of combustion. HCN concentrations of fire victims are not routinely determined in most legal medicine services in Romania. We present the case of a room fire victim in which we evaluated the concentrations of HCN and carboxyhemoglobin (COHb), their contribution to the mechanism of death, and the possibility that HCN concentration can be interpreted as vital sign. COHb was determined by spectrophotometry. HCN was spectrophotometrically determined with ninhydrin in postmortem blood samples after its removal with 20% phosphoric acid and uptake into a solution of potassium carbonate. The presence of ethyl alcohol was determined by gas chromatography. The COHb concentration was 6.15%, while the blood HCN concentration was 1.043 µg × mL and the total HCN was 1.904 µg × ml. A blood alcohol content of 4.36 g‰ and a urine alcohol content of 5.88 g‰ were also found. Although the fire produced a considerable amount of soot, and there were signs of inhalation of soot particles, the COHb level cannot be interpreted as a vital sign. Toxic concentrations of HCN and total HCN can be interpreted as a vital sign and indicates a contributive effect of HCN in the mechanism of death.
PubMed: 33669200
DOI: 10.3390/toxics9020036 -
Enzyme and Microbial Technology Oct 2021Aromatic nitriles are important structural motifs that frequently existed in pharmaceutical drugs. Due to the convenient synthesis of aldoximes from aldehydes, the...
Aromatic nitriles are important structural motifs that frequently existed in pharmaceutical drugs. Due to the convenient synthesis of aldoximes from aldehydes, the dehydration of aldoximes to corresponding nitriles by aldoxime dehydratases (Oxds) is considered as a safe and robust enzymatic production route. Although the Oxd genes are widely distributed in microbial kingdom, so far less than ten Oxds were expressed and further characterized. In this study, we found 26 predicted putative Oxd genes from the GenBank database using a genome mining strategy. The Oxd gene from Pseudomonas putida F1 was cloned and functionally expressed in Escherichia coli BL21 (DE3). The amino acid sequence of OxdF1 shows high identities of 33∼85 % to other characterized Oxds, and contained a ferrous heme as the catalytic site. The optimum reaction pH and temperature of recombinant OxdF1 were 7.0 and 35 °C, respectively. OxdF1 was stable in pH 7.0 potassium phosphate buffer at 30 °C, and its half-life was approximately 3.8 h. OxdF1 can efficiently dehydrate aromatic and heterocyclic aldoximes to nitriles, such as 2-bromobenzaldoxime, 2-chloro-6-fluorobenzaldoxime, thiophene-2-carboxaldoxime, and pyridine-3-aldoxime. Therefore, the recombinant OxdF1 shows a potential application in the cyanide-free synthesis of aromatic nitriles.
Topics: Heme; Hydro-Lyases; Nitriles; Oximes; Pseudomonas putida
PubMed: 34489036
DOI: 10.1016/j.enzmictec.2021.109883 -
Molecules (Basel, Switzerland) Oct 2022Allyl halides with triflamide under oxidative conditions form halogen-substituted amidines. Allyl cyanide reacts with triflamide in acetonitrile or THF solutions in the...
Allyl halides with triflamide under oxidative conditions form halogen-substituted amidines. Allyl cyanide reacts with triflamide in acetonitrile or THF solutions in the presence of NBS to give the products of bromotriflamidation with a solvent interception, whereas in CHCl two regioisomers of the bromotriflamidation product without a solvent interception were obtained. The formed products undergo base-induced dehydrobromination to give linear isomers with the new C=C bond conjugated either with the nitrile group or the amidine moiety or alkoxy group. Under the same conditions, the reaction of allyl alcohol with triflamide gives rise to amidine, which was prepared earlier by the reaction of diallyl formal with triflamide. Unlike their iodo-substituted analogs, bromo-substituted amidines successfully transform into imidazolidines under the action of potassium carbonate.
Topics: Amidines; Solvents; Nitriles; Acetonitriles; Halogens; Imidazolidines
PubMed: 36296503
DOI: 10.3390/molecules27206910 -
Journal of Labelled Compounds &... Feb 2021The two isotopomers of teriflunomide were synthesized starting from isotopically stable-labeled stocks of [ C]potassium cyanide and [1- C]ethyl bromoacetate. The two...
The two isotopomers of teriflunomide were synthesized starting from isotopically stable-labeled stocks of [ C]potassium cyanide and [1- C]ethyl bromoacetate. The two C-labeled compounds 1a, b were applied in several NMR studies to study the E/Z ratio in different matrices. In a solution, such as dimethyl sulfoxide (DMSO), a dynamic equilibrium between E/Z-isomers (ratio of 8:92) was determined by initial C-carbon NMR experiments. To get insights into the E/Z ratio of teriflunomide under in vivo conditions, advanced heteronuclear NMR (heteronuclear Overhauser effect spectroscopy [HOESY]) in D O and mixtures of D O/plasma were performed. Whereas NMR experiments in mixtures of water and plasma failed owing to extreme line broadening, NMR spectra in water at pH 7.4 showed only the Z-isomer.
Topics: Acetates; Carbon Isotopes; Crotonates; Hydrocarbons, Brominated; Hydroxybutyrates; Isomerism; Isotope Labeling; Magnetic Resonance Spectroscopy; Nitriles; Potassium Cyanide; Toluidines
PubMed: 32840004
DOI: 10.1002/jlcr.3876 -
Clinical Toxicology (Philadelphia, Pa.) Aug 2021In this proof-of-concept study, the aim was to evaluate the short-term clinical effectiveness of isosorbide dinitrate (ISDN) oral spray in non-anaesthetized...
OBJECTIVE
In this proof-of-concept study, the aim was to evaluate the short-term clinical effectiveness of isosorbide dinitrate (ISDN) oral spray in non-anaesthetized cyanide-poisoned swine.
METHODS
A comparative study was conducted using domestic swine. Animals were intravenously poisoned with potassium cyanide (KCN), either 2 mg/kg or 4 mg/kg dose. Two control groups (one for each cyanide dose) were not further treated. Two other groups (one for each cyanide dose) were treated within 1 min after poisoning with ISDN oral spray: 3 spray actuations (averaging a total of 3.75 mg) after the lower cyanide dose and 4 spray actuations (averaging a total of 5.0 mg) after the higher dose. The study outcomes were clinical score, time to death, and blood tests including pH, lactate, and methemoglobin levels.
RESULTS
All the animals started to convulse within 20 to 30 sec after KCN poisoning, then became unresponsive and hemodynamically depressed after another 20 to 30 sec. After the KCN 2 mg/kg dose, 3 of 4 control animals survived, while all treated animals survived. Compared with control animals, ISDN-treated animals displayed significantly better clinical scores starting 5 min after KCN poisoning. Acidosis was significantly more pronounced in the untreated animals. After the KCN 4 mg/kg dose, similar survival rates were observed for control and ISDN-treated groups (1/4), but treated animals had longer time to death and better pH and lactate levels.
CONCLUSION
ISDN oral spray administration following KCN poisoning in this porcine model did not result in statistically significant increased survival. However, based on clinical scores and clinical laboratory values, ISDN may benefit as a bridging countermeasure until currently-available specific cyanide antidotes can be administered. Further research is warranted to better characterize this potential role of ISDN in cyanide poisoning.
Topics: Animals; Antidotes; Case-Control Studies; Cyanides; Dose-Response Relationship, Drug; Isosorbide Dinitrate; Lactic Acid; Male; Methemoglobin; Oral Sprays; Potassium Cyanide; Proof of Concept Study; Survival Rate; Swine
PubMed: 33274646
DOI: 10.1080/15563650.2020.1856382 -
Annals of Emergency Medicine Sep 2019Cyanide is a deadly poison, particularly with oral exposure, in which larger doses can occur before any symptoms develop. Multiple governmental agencies highlight oral...
STUDY OBJECTIVE
Cyanide is a deadly poison, particularly with oral exposure, in which larger doses can occur before any symptoms develop. Multiple governmental agencies highlight oral cyanide as an agent that can be used in a terrorist attack because it can be easily weaponized and is readily available. Currently, there are no Food and Drug Administration-approved antidotes specifically for oral cyanide. An oral countermeasure that can neutralize and prevent absorption of cyanide from the gastrointestinal tract after oral exposure is needed. The objective of this study is to determine if the combination of glycine and sodium thiosulfate administered orally is effective in reducing mortality in a large, swine model of oral cyanide toxicity.
METHODS
Nine swine (45 to 55 kg) were instrumented, sedated, and stabilized. Potassium cyanide (at 8 mg/kg) in saline solution was delivered as a onetime bolus through an orogastric tube. Three minutes after cyanide administration, animals that were randomized to the treatment group received sodium thiosulfate (508.2 mg/kg, 3.25-M solution) and glycine (30 mg/kg, 3.5-M solution) through an orogastric tube. Survival at 60 minutes was the primary outcome. We compared survival between groups by log-rank Mantel-Cox analysis and trended laboratory results and vital signs.
RESULTS
At baseline and treatment, all animals were similar. Survival at 60 minutes was 100% in treated animals compared with 0% in the control group (P=.003). By the study end, defined as death or 60 minutes after cyanide administration, there was a significant difference in the lactate concentration between the treatment and control groups (control 9.43 mmol/L [SD 4.08]; treatment 1.66 mmol/L [SD 0.82]; difference between means 7.69 mmol/L [SD 2.07]; 95% confidence interval difference -14.05 to -1.32). Mean arterial pressure was significantly different between the treatment and control groups at study end (control 26 mm Hg [SD 6.7]; treatment 81 mm Hg [SD 14]; difference between means 55.2 mm Hg [SD 7.1]; 95% confidence interval difference 37.8 to 72.6). pH and oxygen saturation were also significantly different between the treatment and control groups at study end.
CONCLUSION
The combination of oral sodium thiosulfate and glycine significantly improved survival and physiologic parameters in a large-animal model of oral cyanide toxicity.
Topics: Administration, Oral; Animals; Antidotes; Disease Models, Animal; Drug Therapy, Combination; Female; Glycine; Humans; Poisons; Potassium Cyanide; Random Allocation; Swine; Thiosulfates; Time Factors
PubMed: 31080026
DOI: 10.1016/j.annemergmed.2019.03.023