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Journal of Ethnopharmacology Jan 2022Different parts of Antiaris africana Englea (Moraceae) are used traditionally for the treatment of various diseases, including epilepsy and other nervous system...
ETHNOPHARMACOLOGICAL RELEVANCE
Different parts of Antiaris africana Englea (Moraceae) are used traditionally for the treatment of various diseases, including epilepsy and other nervous system disorders.
AIMS OF THIS STUDY
The current study was designed to evaluate the neuroprotective activity of flavonoids isolated from A. africana against potassium cyanide (KCN)-induced oxidative damage in brain homogenate.
MATERIALS AND METHODS
Dried and ground leaves of A. africana were extracted with methanol and fractioned into n-hexane (HFA), dichloromethane (DFA), ethyl acetate (EFA) and methanol (MFA). Each fraction was assessed for neuroprotective potential by anticholinesterase activity test. The fraction with the best anticholinesterase activity was subjected to various chromatographic techniques through bioassay-guided fractionation to isolate the bioactive compounds. The protective ability of the extract, fractions and compounds against Potassium cyanide (KCN)-induced mitochondrial damage in rat brain homogenate was evaluated. Structures of the isolated compounds were determined using 1D and 2D NMR, mass spectrometry and by comparison with literature data.
RESULTS AND DISCUSSION
The ethyl acetate fraction showed the best anticholinesterase activity with an IC of 23.23 ± 1.12 μg/ml. Quercetin and a biflavonoid glucoside identified as 3'-4'-bisquercetin-3β-D-diglucoside from this fraction displayed a remarkable antioxidant activity in the DPPH assay and showed significant (P < 0.05) increase in the activity of dehydrogenase inhibited by KCN in a concentration dependent manner. However, quercetin was more effective in reducing the MDA level and acetylcholinesterase activity that were elevated by KCN.
CONCLUSION
Quercetin and the bisquercetin-diglucoside isolated from the leaves of A. Africana for the first time, are major contributors to the observed neuroprotective property of the plant which supports its folkloric usage in the management of seizures, epilepsy and other neurological disorders.
Topics: Animals; Antiaris; Antioxidants; Cholinesterase Inhibitors; Flavonoids; Medicine, Traditional; Nervous System Diseases; Neuroprotective Agents; Oxidative Stress; Plant Extracts; Plant Leaves; Potassium Cyanide; Quercetin; Rats
PubMed: 34480996
DOI: 10.1016/j.jep.2021.114592 -
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 -
Acta Crystallographica. Section E,... Aug 2021The investigation of the coordination chemistry of rare-earth metal complexes with cyanide ligands led to the isolation and crystallographic characterization of the...
The investigation of the coordination chemistry of rare-earth metal complexes with cyanide ligands led to the isolation and crystallographic characterization of the cyano-tri-phenyl-borate complexes di-chlorido-(cyano-tri-phenyl-borato-κ)tetra-kis-(tetra-hydro-furan-κ)lanthanide(III), [Cl(CHBN)(CHO)] [lanthanide () = dysprosium (Dy) and yttrium Y)] from reactions of LnCl, KCN, and NaBPh. Attempts to independently synthesize the tetra-ethyl-ammonium salt of (NCBPh) from BPh and [NEt][CN] in THF yielded crystals of the phenyl-substituted cyclic borate, tetra-ethyl-aza-nium 2,2,4,6-tetra-phenyl-1,3,5,2λ,4,6-trioxatriborinan-2-ide, CHN·CHBO or [NEt][B(μ-O)(CH)]. The mechanochemical reaction of BPh and [NEt][CN] without solvent produced crystals of tetra-ethyl-aza-nium cyano-diphenyl-λ-boranyl di-phenyl-borinate, CHN·CHBNO or [NEt][NCBPh(μ-O)BPh]. Reaction of BPh and KCN in THF in the presence of 2.2.2-cryptand (crypt) led to a crystal of bis-[(2.2.2-cryptand)potassium] 2,2,4,6-tetra-phenyl-1,3,5,2λ,4,6-trioxatriborinan-2-ide cyano-methyl-diphenyl-borate tetra-hydro-furan disolvate, 2CHKNO ·CHBO ·CHBN·2CHO or [K(crypt)][B(μ-O)(CH)][NCBPhMe]·2THF. The [NCBPh(μ-O)BPh] and (NCBPhMe) anions have not been structurally characterized previously. The structure of was refined as a two-component twin with occupancy factors 0.513 (1) and 0.487 (1). In , one solvent mol-ecule was disordered and included using multiple components with partial site-occupancy factors.
PubMed: 34422304
DOI: 10.1107/S2056989021006861 -
Clinical and Experimental Pharmacology... Dec 2021Serotonin (5-HT) accumulates in the heart during myocardial ischaemia and induces deleterious effects on the cardiomyocytes. We aimed to investigate whether...
Serotonin (5-HT) accumulates in the heart during myocardial ischaemia and induces deleterious effects on the cardiomyocytes. We aimed to investigate whether carrier-mediated 5-HT efflux contributed to the increase in interstitial 5-HT level during ischaemia. Using microdialysis technique applied to the heart of anaesthetised Wistar rats, myocardial interstitial concentration of 5-HT was measured by electro-chemical detection coupled with high-performance liquid chromatography (HPLC-ECD) while simultaneously various pharmacological agents, which create a similar condition to ischaemia, were locally administered by reverse-microdialysis. Sodium cyanide-induced chemical anoxia increased dialysate 5-HT concentration. A similar increase in dialysate 5-HT concentration was induced by ouabain, an inhibitor of sodium-potassium ATPase and reserpine, an inhibitor of vesicular monoamine transporter. Fluoxetine, a selective serotonin reuptake inhibitor raised the baseline level of 5-HT, and neither sodium cyanide nor the combination of ouabain and reserpine induced further increase in 5-HT in the presence of fluoxetine. The results indicate that reverse transport of 5-HT via SERT, which is caused by an impaired ion gradient, contributes to the rise in interstitial level of 5-HT during ischaemia suggesting carrier-mediated 5-HT efflux occurs in the heart in vivo.
Topics: Serotonin
PubMed: 34411314
DOI: 10.1111/1440-1681.13576 -
Data in Brief Aug 2021This research data set contains data related to experimental dataset on the effect of the electron acceptors in energy generation from brewery wastewater via a microbial...
This research data set contains data related to experimental dataset on the effect of the electron acceptors in energy generation from brewery wastewater via a microbial fuel cell. The presented data gives information on the generation of electricity and waste minimization as various electron acceptors adopted in microbial fuel cells. Dual-chamber microbial fuel cell (MFC) system was assembled with aluminium mesh electrode as an anode and sulfonated tetrafluoroethylene membrane for proton exchange as a cathode at 500-2000 mg/L chemical oxygen demand (COD). A 0.4 and 0.6 M of Potassium permanganate (KMnO) and potassium cyanide K[Fe(CN) were used anaerobically as a mediator for electron acceptor in the cathode chamber. Furher more, The pH, COD, total nitrogen, biochemical oxygen demand, total phosphorous, total suspended solid and electrical conductivity for the raw brewery wastewater were measured. Inaddition, the voltage generated and the current density have been obtained for both (KMnO) and K[Fe(CN) electron acceptors. Moreover, the COD removal efficiency, Columbic efficiency, voltage generation, current, and power density were measured.
PubMed: 34409139
DOI: 10.1016/j.dib.2021.107272 -
Scientific Reports Jul 2021Sodium azide is an old poison with toxicity comparable to potassium cyanide. It would seem to be completely forgotten however, between 2000 and 2020, the number of...
Sodium azide is an old poison with toxicity comparable to potassium cyanide. It would seem to be completely forgotten however, between 2000 and 2020, the number of intentional ingestions and murders committed with sodium azide significantly increased. Furthermore, due to its extreme instability, sodium azide is difficult to detect, which poses an additional risk when used to commit a crime. In this study, the epidemiology of sodium azide exposures between 1920 and 2020 was investigated. For the determination the azide concentration in biological samples, a simple, precise and selective headspace gas chromatography method (HS-GC-FID/FID) was developed and fully validated. The limit of quantification was 0.65 µg/mL; and the limit of detection was 0.35 µg/mL; precision and accuracy did not exceed 20%. The stability study was conducted for various biological fluids (urine, bile, blood, gastric content) for 91 days in the refrigerator (4 °C) and the method for stabilization of azide was presented. The addition of a mixture of borax and sodium fluoride (w/w 3:1) to the test tubes can stabilize this poison. The described unique technique of collecting the biological samples poses a great potential for azide detection in clinical and toxicology laboratories even long time after human exposure to this substance.
Topics: Azides; Chromatography, Gas; Sodium Azide
PubMed: 34330976
DOI: 10.1038/s41598-021-95104-5 -
Journal of the American Chemical Society Jul 2021The stereoselective cyanoalkylation of electron-deficient olefins with potassium cyanide and alkyl halides was developed based on the utilization of modular chiral...
The stereoselective cyanoalkylation of electron-deficient olefins with potassium cyanide and alkyl halides was developed based on the utilization of modular chiral 1,2,3-triazolium salts featuring a hydrogen bond-donor ability as catalysts. The reaction involving multiple carbon-carbon bond formations proceeds via the enantioselective conjugate addition of a cyanide ion and the consecutive catalyst-controlled diastereoselective alkylation of intermediary chiral triazolium enolates. Control experiments revealed that the use of a properly tuned chiral triazolium ion as a catalyst and the presence of the cyano functionality in the intermediary enolate are of crucial importance for achieving high levels of acyclic absolute and relative stereocontrol.
PubMed: 34270904
DOI: 10.1021/jacs.1c05380 -
Plant, Cell & Environment Nov 2021Flooding is a major environmental constraint that obliges plants to adopt plastic responses in order to cope with it. When partially submerged, tomato plants undergo...
Flooding is a major environmental constraint that obliges plants to adopt plastic responses in order to cope with it. When partially submerged, tomato plants undergo profound changes involving rearrangements in their morphology and metabolism. In this work, we observed that partial submergence markedly dampens root respiration and halts root growth. However, the flooded hypocotyl surprisingly enhances oxygen consumption. Previous results demonstrated that aerenchyma formation in the submerged tomato stem re-establishes internal oxygen tension, making aerobic respiration possible. Indeed, potassium cyanide abruptly stops oxygen uptake, indicating that the cytochrome c pathway is likely to be engaged. Furthermore, we found out that leaf-derived sugars accumulate in large amounts in hypocotyls of flooded plants. Girdling and feeding experiments point to sucrose as the main carbon source for respiration. Consistently, submerged hypocotyls are characterized by high sucrose synthase activity, indicating that sucrose is cleaved and channelled into respiration. Since inhibition of hypocotyl respiration significantly prevents sugar build-up, it is suggested that a high respiration rate is required for sucrose unloading from phloem. As substrate availability increases, respiration is fuelled even more, leading to a maintained allocation of sugars to flooded hypocotyls.
Topics: Floods; Hypocotyl; Solanum lycopersicum; Plant Roots; Plant Stems; Sucrose
PubMed: 34268805
DOI: 10.1111/pce.14152 -
Clinical Toxicology (Philadelphia, Pa.) Jan 2022Cyanide (CN) is a metabolic poison that is capable of intoxicating individuals through accidental or intentional means. With high concentration exposures, death can...
BACKGROUND
Cyanide (CN) is a metabolic poison that is capable of intoxicating individuals through accidental or intentional means. With high concentration exposures, death can occur in minutes. In cases of mass casualty exposures, there is a need for a rapid-acting countermeasure capable of being administered in a short period of time in a pre-hospital setting to treat victims.
OBJECTIVE
These studies evaluate the safety and efficacy of a novel aqueous formulation of dimethyl trisulfide (DMTS) as an intramuscular (IM) CN countermeasure using non-anesthetized rodent models.
METHODS
Non-anesthetized rodents (mice and rats) were exposed to hydrogen cyanide (HCN) or potassium cyanide (KCN) along with immediate IM 10% DMTS treatment or vehicle treatment. Survival and other parameters, such as the time to recovery and assessment of clinical toxic signs (e.g., gasping, loss of righting reflex, convulsions, etc.), were quantified to determine the effectiveness of 10% DMTS treatment (12.5, 25, 75 mg/kg IM) compared to vehicle control treatment. A rat KCN delayed-treatment model with a 15-minute treatment delay was also utilized to simulate a real-life exposure/treatment scenario with 10% DMTS treatment. The stability of the 10% DMTS formulation was also assessed.
RESULTS
A 25 mg/kg IM dose of 10% DMTS exhibits potent efficacy against subcutaneous (SC) KCN challenge in both mice and rats and inhalational HCN exposure in mice. 10% DMTS treatment also shortens the time to recovery in rats using a delayed-treatment model.
CONCLUSION
IM treatment with 10% DMTS improves survival and clinical outcomes in non-anesthetized rodent models of acute CN toxicity. Additionally, the use of an SC KCN delayed-treatment model in rats is advised to assess the performance of a candidate CN countermeasure in a more realistic exposure/treatment scenario.
Topics: Animals; Antidotes; Cyanides; Humans; Mice; Potassium Cyanide; Rats; Sulfides
PubMed: 34219566
DOI: 10.1080/15563650.2021.1935991 -
International Journal of Molecular... Jun 2021A novel cytoplasmic dye-decolorizing peroxidase from was investigated that oxidizes anthraquinone dyes, lignin model compounds, and general peroxidase substrates such...
A novel cytoplasmic dye-decolorizing peroxidase from was investigated that oxidizes anthraquinone dyes, lignin model compounds, and general peroxidase substrates such as ABTS efficiently. Unlike related enzymes, an aspartate residue replaces the first glycine of the conserved GXXDG motif in DyPA. In solution, DyPA exists as a stable dimer with the side chain of Asp146 contributing to the stabilization of the dimer interface by extending the hydrogen bond network connecting two monomers. To gain mechanistic insights, we solved the DyPA structures in the absence of substrate as well as in the presence of potassium cyanide and veratryl alcohol to 1.7, 1.85, and 1.6 Å resolution, respectively. The active site of DyPA has a hexa-coordinated heme iron with a histidine residue at the proximal axial position and either an activated oxygen or CN molecule at the distal axial position. Asp149 is in an optimal conformation to accept a proton from HO during the formation of compound I. Two potential distal solvent channels and a conserved shallow pocket leading to the heme molecule were found in DyPA. Further, we identified two substrate-binding pockets per monomer in DyPA at the dimer interface. Long-range electron transfer pathways associated with a hydrogen-bonding network that connects the substrate-binding sites with the heme moiety are described.
Topics: Catalysis; Catalytic Domain; Coloring Agents; Crystallography, X-Ray; Dictyostelium; Heme; Hydrogen Bonding; Hydrogen Peroxide; Oxidation-Reduction; Peroxidase
PubMed: 34200865
DOI: 10.3390/ijms22126265