Carbohydrazide Research Articles

Development and optimization of an in-house heterologous ELISA for detection of prednisolone drug in enzyme conjugates using spacers.

The introduction of spacers in coating steroid protein complexes and/or enzyme conjugates or immunogens is known to exert an influence on the sensitivity of steroid enzyme immunoassays. We investigated the impact of different homobifunctional spacers, ranging in atomic length from 3 to 10, on the sensitivity and specificity of prednisolone (PSL) enzyme immunoassays. In this study, four homo-bifunctional spacers, namely, carbohydrazide (CH), adipic acid dihydrazide (ADH), ethylene diamine (EDA), and urea (U), were incorporated between PSL and horseradish peroxidase (HRP) for preparing the enzyme conjugate with an aim to improve the sensitivity of the assay without compromising assay specificity. The assays were developed using these enzymes conjugated with antibodies raised against the PSL-21-HS-BSA immunogen. The sensitivity of the PSL assays after insertion of a bridge in the enzyme conjugate was 1.22 ng/mL, 0.59 ng/mL, 0.48 ng/mL, and 0.018 ng/mL with ADH, CH, EDA, and urea as a spacer, respectively. Among the four combinations, the PSL-21-HS-BSA-antibody with PSL-21-HS-U-HRP-enzyme conjugate gave better sensitivity and less cross-reaction. The percent recovery of PSL from the exogenously spiked human serum pools was in the range of 88.32%-102.50%. The intra and inter-assay CV% was< 8.46%. The PSL concentration was estimated in the serum samples of patients on PSL treatment. The serum PSL values obtained by this method correlated well with the commercially available kit (r2 = 0.98). The present study suggests that the nature of the spacer is related to assay sensitivity and not the spacer length.

Carbohydrazide-Assisted Morphology and Structure Controlling for Lead-Free Cs2AgBiBr6 Double Perovskite Solar Cells.

The stability and toxicity problems have haunted the development and applications of metal halide perovskite materials, for which the lead-free inorganic double perovskite Cs2AgBiBr6 has emerged as a promising substitute in recent years. However, poor film quality has severely limited its photovoltaic performance that could have been induced by some key factors such as high annealing temperature. Herein, we present a facile strategy to fabricate high-quality pinhole-free Cs2AgBiBr6 films with large grain sizes by introducing carbohydrazide (CBH) into the precursor. Detailed characterizations have shown that the carbonyl group (C═O) in CBH plays the critical role in coordinating with Ag+ and Bi3+ cations during the film formation process. As another consequence, the as-fabricated devices have exhibited significantly higher reproducibility for fabrication. By optimizing the amount of CBH, the power conversion efficiency (PCE) relatively increased 37 to 1.57%, which remained 95.0% in an ambient environment for a 1000-h test. Hopefully, this work could facilitate the current technologies in the exploration of high-performance lead-free perovskites such as Cs2AgBiBr6 and better understanding of the mechanism in the additive engineering as well.

Bioinspired Fast Room-Temperature Self-Healing, Robust, Adhesive, and AIE Fluorescent Waterborne Polyurethane via Hierarchical Hydrogen Bonds and Use as a Strain Sensor.

Developing a new generation of ecofriendly water-based polymeric materials that integrate mechanical robustness, fast room-temperature self-healing, adhesive, and fluorescence remains a formidable challenge. Herein, inspired by titin protein, a series of novel waterborne polyurethanes (WPU-CHZ-NAGA) containing irregular 6-fold and diamide hydrogen bonds are synthesized by introducing carbohydrazide (CHZ) and N,N-bis(2-hydroxyethyl)-3-amino propionyl glycinamide (HO-NAGA-OH) groups. The representative WPU-CHZ2-NAGA3 exhibits outstanding mechanical properties (tensile strength of 36.58 MPa, tearing energy of 81.2 kJ m-2, and toughness of 125.82 MJ m-3) and fast room-temperature self-healing ability with the aid of ethanol (≥90% within 8 h) originated from hierarchical hydrogen bonds. These properties are superior to those of most of the reported room-temperature self-healing polymer materials. Benefiting from plentiful hydrogen bonds, the WPU matrix achieves excellent adhesive properties without heating or adding curing agents. Interestingly, WPU-CHZ2-NAGA3 film emits inherent blue fluorescence due to the aggregation-induced emission effect of tertiary amine groups, and its potential applications in information encryption and anticounterfeiting are further demonstrated. Specially, a eutectic gel strain sensor is also fabricated with WPU-CHZ2-NAGA3 and deep eutectic solvent by a simple physical blending method, which can be used to monitor the movement of human fingers and wrists as well as the change in body temperature. In summary, this work provides new insight into the design and synthesis of multifunctional WPU with fast room-temperature self-healing and high mechanical properties.

Regulating 3D Phase in Quasi-2D Perovskite Films for High-Performance and Stable Photodetectors.

The charge transport in quasi-2D perovskites limits their applications despite the superior stability and optoelectronic properties. Herein, a novel strategy is proposed to enhance the charge transport by regulating 3D perovskite phase in quasi-2D perovskite films. The carbohydrazide (CBH) as an additive is introduced into (PEA)2 MA3 Pb4 I13 precursors, which slows down the crystallization process and improves the phase ratio and crystal quality of the 3D phase. This structure change results in a significant improvement in charge transport and extraction, leading to the device demonstrating an almost 100% internal quantum efficiency, a peak responsivity of 0.41AW-1 , and a detectivity of 1.31×1012 Jones at 570nm under 0V bias. Furthermore, the air and moisture stability of (PEA)2 MA3 Pb4 I13 films is not deteriorated but gets significantly improved due to the better crystal quality and the passivation of defects by the residual CBH molecule. This work demonstrates a strategy for improving the charge transport properties of quasi-2D perovskites and also sheds light on solving the stability issue of 3D perovskite films via the proper passivation or additives, which will inspire the fast development of the perovskite community.

Film-forming amine product as an alternative to carbohydrazide oxygen scavenger in high pressure boilers

Hydrazine has been largely replaced by carbohydrazide (CHZ) as an oxygen scavenger due to safety and health concerns and CHZ is now used in Saline Water Conversion Corporation (SWCC) high pressure boilers. However, the operational problem of phosphate hide-out has become a continuous challenge for the plant operators. Advances in boiler water treatment have shown that effective corrosion control and prevention of scaling can be achieved by using a mixture of film-forming and alkalizing amines and polycarboxylates [Film Forming Amine Product (FFAP)]. With the use of FFAP, carbohydrazide/ammonia treatment of make-up water and phosphate treatment in the drum will not be required. A uniform FFAP formulation was used throughout the test.The evaluation study was carried out at a boiler of the Yanbu Phase 1 Desalination and Power Plant (Mitsubishi) generating 60 MWh, with make-up water of 15 t h−1 producing 330 t h−1 steam at a pressure of 67 barg and temperature of 480 °C.The trial provided evidence that FFAP was a good alternative to use of an oxygen scavenger. Changeover from CHZ to FFAP without phosphate addition in the drum was done initially by dosing FFAP from both hydrazine tank and phosphate tank so that pH was maintained to the required values in both feed water and drum water. With the optimal dose rate (0.6 ppm) maintaining FFAP in the range of 0.3–1.0 ppm in feed water, all the key parameters (pH, ammonia and specific conductivity) were within the specified boiler design limits. The average corrosion rates on the water side were low for both CHZ and FFAP treatment (0.009 ± 0.001 mm y−1), however FFAP treated coupons showed much lower corrosion rates compared to CHZ in the steam side (0.0006 ± 0.0003 mm y−1 cf. 0.0075 ± 0.0006 mm y−1).

Self‐Supporting and Shell‐Core Pd−Ni@Ni Nanowire Arrays Electrode as Anode of Direct Carbohydrazide Fuel Cell

AbstractConsidering the excessively high onset potential on pure Ni catalyst and the generation of gaseous products in carbohydrazide (CHZ) electrooxidation, a self‐supporting and shell‐core Pd−Ni@Ni nanowire arrays (NAs) catalytic electrode is prepared by the first templating electrodeposition of Ni and the subsequent galvanic replacement of Pd. The introduction of Pd with minute mass loadings of 2.7–5.3 μg cm−2 enables a negative shift of onset potential of CHZ electrooxidation by 320 mV regardless of Ni supports. Pd in Ni@Pd−Ni NAs electrode can facilitate the chemical dissociation of CHZ into N2H4 and/or H2 and then provoke the occurrence of side reactions, i. e., N2H4 and/or H2 electrooxidation. The direct CHZ fuel cell made of Ni@Pd−Ni NAs anode delivers an open circuit voltage of 1.05 V and a peak power density of 22.90 mV cm−2 at the operating temperature of 303 K.

Thermal behavior and thermolysis mechanisms of graphene oxide-intercalated energetic complexes of carbohydrazide

Graphene-based carbohydrazide coordination polymers are beneficial for improving solid propellants’ energy level and safety, so the study of their thermal decomposition mechanism is promoted for their wide application. In this paper, graphene oxide (GO) intercalated transition metal (Cu2+, Co2+, and Ni2+) complexes of carbohydrazide (CHZ) have been evaluated by using DSC/TGA apparatus and the TG-FTIR technique. Both isoconversional and combined kinetic methods were employed to calculate the kinetic parameters. The components inside GOCHZ-M would react with each other to cause a large mass loss rate and lead to a larger heat-releasing value than pure GO. The types of metal ions could affect their reaction model. Compared with GO, G-CHZ-Co shows a two-sided effect (stabilization and catalytic) on its decomposition. For G-CHZ-Co, the reaction model of each peak is close to the random 2d nucleation and nucleus growth model.

Highly stable and permeable graphene oxide membrane modified by carbohydrazide for efficient dyes separation

As natural resources become more and more limited, it is exceptionally essential to decrease energy consumption in membrane separation processes, which makes membranes with ultra-high water permeance increasingly expected. Graphene oxide (GO) membranes have exhibited an unsurpassed future for wastewater purification. However, it is two key challenges to greatly increase the water permeance while retaining the removal efficiency of contaminants and improve the enduring stability of membranes in aqueous solution. In this work, the membranes with ultrafast water permeability were prepared by self-assembly vacuum filtration method using carbohydrazide (CHZ) as reducing and cross-linking agent. The obtained lamellar rGO/CHZ nanofiltration membranes exhibited water permeance bigger than 1600 L m-2h−1 bar−1, and outstanding separation efficiency, e.g., Congo Red (CR), Malachite Green (MG), and Crystal Violet (CV) removal rate of 99%. More importantly, the composite membrane exhibited efficiently selective separation of various mixed dyes. Such as binary mixed dyes of MG/MO, the removal rate of MG is 99%, while the removal rate of MO is merely 23%. In addition, the membrane still showed excellent stability after long-term immersion in solutions of various pH values. The separation performance in terms of complete rejection of single dyes and selective filtration of mixed dyes makes them one of the promising materials for dye separation, purification, and reuse.

Application of Microwave Radiation to Produce Uranium Dioxide Powder from Its Trioxide

The possibility of producing UO2 powder from UO3 using microwave radiation (power 300 W) in the presence of organic compounds with amino groups: carbohydrazide (CH), acetohydroxamic (AHA), and aminoacetic (glycine) acids has been investigated. It was found that in these processes in an oxygen-free atmosphere, UO2 is produced from UO3, and in an air, U3O8. It was shown that under the action of microwave radiation in the presence of CH and AHA, powdered UO2 are synthesized from UO3. The physical properties of the powders obtained (bulk density with tapping 2.6–2.7 g/cm3, specific surface area up to 3.2 m2/g, moisture content less than 0.1 wt %) meet the requirements for ceramic-quality powders in the production of fuel pellets.

SYNTHESIS OF (Z)-N'-(PHENYL(PYRIDIN-2-YL)METHYLENE)-NICOTINOHYDRAZIDE: STRUCTURAL CHARACTERIZATION AND ANTIOXIDANT ACTIVITY SCREENING

Asymmetrical ligand ( Z )- N '-(phenyl(pyridin-2-yl)methylene)nicotinohydrazide ( I ) was synthesized from the condensation of nicotinic acid hydrazide with 2-benzoylpyridine. The compound was characterized by physicochemical analyses, elemental analysis, FTIR, 1 H and 13 C NMR spectroscopy techniques. The structure of the compound was determined by a single-crystal X-ray diffraction study. The ligand crystallizes in the triclinic space group P-1 with the following unit cell parameters: a = 8.2699 (11) A, b = 8.6514 (8) A, c = 11.583 (11) A, a = 91.308 (3)°, b = 94.155 (5)°, g = 109.008 (4)°, V = 755.17 (14) A 3 , Z = 2, R 1 = 0.050, wR 2 = 0.145. The carbonohydrazone moiety of the molecule is slightly twisted as reflected by the torsion angles values of -1.2 (2)° [O1—C13—N3—N2]. The dihedral angle between the mean planes of the pyridine rings is 11.799 (9)°. The crystal packing of compound ( I ) is stabilized by intramolecular N(carbohydrazide)–H···N(pyridine) and intermolecular C(phenyl)–H···O(amide) and C(phenyl)–H···N(hydrazino) hydrogen bonds, leading to the formation of sheets parallel to ac plane. The compound screened for antioxidant activity showed variable DPPH inhibition value for different concentrations of DPPH solution.

SYNTHESIS , CHARACTERIZATION AND STUDY BIOLOGICAL ACTIVITY SOME NEW DERIVATIVES AMIDE AND PYRAZOLE –PYRAZOLINE OF STEROID ANALOGS .

ABSTRACT&#x0D; The number of steroids and their derivatives possess divers pharmacological activities as drugs for the treatment of a large number of diseases so in this work was suggested prepared two series amides and pyrazoles of steroid analogs ( methyl((5-pregnant-3β,17-diol-15-yl) thio) propanoate) . Amides derivatives ( 6 - 9 ) prepared directionally after treated the steroid analogs with primary amine substituted in basic medium . Carbo hydrazide steroid derivative (10 ) was obtained by treated steroid analogs with hydrazine hydrate , this compound use as intermediate for synthesis Pyrazolin (13 ) as well as Pyrazole (14) .&#x0D; All the newly synthesized compounds have been identified by IR, 1H NMR, 13CNMR, 2D-NMR ( HMBC , HSQC ) and C.H.N Analysis

Carbohydrate triazole tethered 2-pyridyl-benzimidazole ligands: Synthesis of their palladium (II) complexes and antimicrobial activities

A series of carbohydrate-tethered 1-triazolyl-2-pyridyl-benzimidazole ligands have been prepared and the antimicrobial activity of their Pd(II) complexes has been studied. The alkyne, 1-propargyl-2-pyridyl-benzimidazole (2) was synthesized by the reaction of 2-pyridyl-benzimidazole and propargyl bromide in the presence of sodium hydride. The carbohydrate triazoles (4a-e) were synthesized by the Huisgen 1,3-dipolar cycloaddition reaction of alkyne (2) and different carbohydrate azides (3a-e). For comparative studies, benzyl triazole ligand (4f) was also synthesized. The palladium complexes (5a-f and 6), obtained from the reaction of the ligands (4a-f and 2 respectively) and Pd(COD)Cl2 (1:1 ratio) in dichloromethane solution, were characterized by NMR, mass and elemental analysis. All the ligands and metal complexes were tested for the antibacterial activity against Gram positive and Gram negative bacterial strains. In this study, the ligands have displayed superior antimicrobial activity as compared to their corresponding metal complexes.

Synthesis, characterization of some novel 1,3,4-oxadiazole compounds containing 8-hydroxy quinolone moiety as potential antibacterial and anticancer agents

In the present work a series of novel derivatives of 8-hydroxy quinolone substituted 1,3,4-oxadiazole compounds were synthesized by convergent synthetic method and studied for their antibacterial and anticancer properties. The cell lines used for cytotoxic evaluation were HeLa , Caco-2 and MCF7 . The synthetic chemistry involved conversion of various substituted aromatic acids into ethyl ester 2a-e . The ethyl ester was converted into corresponding carbohydrazide 3a-e . Carbohydrazides are reacted with chloroacetic acid, phosphorous oxytrichloride and irradiated with microwave in order to obtain the various key intermediates 2-(chloromethyl)-5-(substituted phenyl)-1,3,4-oxadiazole 4a-e . The 2-(chloromethyl)-5-(substituted phenyl)-1,3,4-oxadiazole was reacted with 8-hydroxy quinolone in presence of sodium hydride and obtained a series of 8-hydroxy quinoline substituted 1,3,4-oxadiazoles 5a-e . Among the synthesised compounds, the cytotoxicity of the compound 5b i.e. 8-{[5-(2,4-dichlorophenyl)-1,3,4-oxadiazol-2-yl]methoxy}quinoline against MCF7 with IC 50 of 5.3µM and the compound 5e i.e. 8-{[5-(4-bromophenyl)-1,3,4-oxadiazol-2-yl]methoxy}quinoline showed MIC of < 6.25µg/mL against Staphylococcus aureus which is comparable with the known standards. The standards used for cytotoxic evaluation was 5-fluorouracil and for antibacterial was nitrofurazone

ChemInform Abstract: Exploration of Fluoral Hydrazones Derived from Carbohydrazides for the Synthesis of Trifluoromethylated Heterocycles.

ChemInform Abstract: Exploration of Fluoral Hydrazones Derived from Carbohydrazides for the Synthesis of Trifluoromethylated Heterocycles.

(4-Ferrocenylphenyl)propargyl ether derived carbohydrate triazoles: influence of a hydrophobic linker on the electrochemical and cytotoxic properties

In this article we describe a detailed study of the influence of a hydrophobic linker on the properties of a series of ferrocene–carbohydrate conjugates. The alkyne, (4-ferrocenylphenyl)propargyl ether, was prepared from the reaction of propargyl bromide and 4-ferrocenylphenol. The structure of the alkyne was determined using a single crystal X-ray diffraction study. A benzyl triazole (3a) was synthesised for comparison purposes in the electrochemical and cytotoxic study. Herein, we report the synthesis and characterization of a series of carbohydrate triazole conjugates (3b–h) by using the Huisgen 1,3-dipolar cycloaddition reaction of a series of carbohydrate azides and (4-ferrocenylphenyl)propargyl ether. UV-visible spectroscopy and electrochemical studies were performed on the alkyne and triazole compounds. The data generated from the cyclic voltammetric studies was used to calculate the diffusion coefficients (Df) of the ferrocene–carbohydrate conjugates in DMSO and DMSO–buffer solutions. Slightly higher diffusion coefficient values were obtained for the carbohydrate triazole conjugates (3b–h) in the buffer solution, perhaps due to the hydrophobic nature of the linker and the absence of a hydrogen-bonding substituent adjacent to the ferrocene core. Furthermore, the triazole conjugate (3f) derived from ribofuranose exhibited significant cytotoxicity against a hormone dependent breast cancer cell line (MCF-7) with an IC50 value lower than 10 μM.

Research on thermal decomposition of trinitrophloroglucinol salts by DSC, TG and DVST

Abstract The thermal decomposition of the four nitrogen-rich salts of ammonia (NH4), aminoguanidine (AG), carbohydrazide (CHZ) and 5-aminotetrazo (ATZ) based on trinitrophloroglucinol (H3TNPG) was investigated using the differential scanning calorimetry (DSC), thermogravity (TG), and dynamic vacuum stability test (DVST). DSC and TG methods research the complete decomposition, while DVST method researches the very early reaction stage. The peak temperatures of DSC curves are consistent with the temperatures of maximum mass loss rates of TG curves. The apparent activation energies of these H3TNPG-based salts obtained by DSC and DVST have the same regularity, i.e., (ATZ)(H2TNPG)·2H2O 2O 4(H2TNPG) 2TNPG). The thermal stability order is (ATZ)(H2TNPG)·2H2O 2O 2TNPG) 4(H2TNPG), which was evaluated by DVST according to the evolved gas amount of thermal decomposition. DVST can monitor the real-time temperature and pressure changes caused by thermal decomposition, dehydration, phase transition and secondary reaction, and also evaluate the thermal stability and kinetics.

Water-Dependent Reduction of Carbohydrate Azides by Dithiothreitol

Dithiothreitol efficiently reduces carbohydrate azides in aqueous acetonitrile to give good-to-excellent yields of the corresponding amines or, after N-acetylation, acetamides. This reduction can proceed in either the presence or the absence of a base.

Effect of amide-triazole linkers on the electrochemical and biological properties of ferrocene-carbohydrate conjugates

Amide-triazole linker incorporated ferrocene-carbohydrate conjugates were prepared by adopting a regiospecific copper(II)-catalysed 1,3-cycloaddition of ferrocenoyl propargylamide and isopropylidene/acetyl protected carbohydrate azides. Hydrophilic ferrocene glycoside with an amide-triazole linker was synthesised by deacetylation of the hydroxyl groups. All the new compounds were characterised by UV-visible and electrochemical studies and they were found to be stable in organic solvents as well as in the buffer system under physiological conditions (pH = 7.0). The diffusion coefficient (D(f)) of the conjugates was also calculated by means of cyclic voltammetric studies. It was observed that while the molecular weight of the compounds had no significant effect on the diffusion coefficient, the hydrophobic/hydrophilic nature of the carbohydrate scaffold displayed varied diffusion coefficient values. Stabilization of the compounds in buffer solution under physiological pH led to almost identical diffusion coefficient values. The compounds derived from xylose and ribose exhibited cytotoxicity on hormone-dependent and hormone-independent breast cancer cell lines, whereas the conjugates derived from glucose and galactose were found to be non-toxic in nature. The compounds did not show any antimicrobial activity against Gram-positive and Gram-negative pathogens.

Synthesis, crystal structure, thermal decomposition, and non-isothermal reaction kinetic analysis of an energetic complex: [Mg(CHZ)3](ClO4)2 (CHZ = carbohydrazide)

An energetic complex [Mg(CHZ)3](ClO4)2 was synthesized by the reaction of carbohydrazide (CHZ) with magnesium perchlorate. The product was characterized by X-ray single-crystal diffraction, elemental analysis, and IR spectroscopy. The crystal belongs to the monoclinic system with space group P2(1)/n. Cell parameters: a = 10.034(2) Å, b = 8.5069(16) Å, c = 21.285(4) Å, β = 100.901(3)°, V = 1784.1(6) Å3, Z = 4. The central magnesium is six-coordinate with three oxygen atoms of carbonyl groups and three terminal nitrogen atoms of the hydrazine groups from three CHZs to form a distorted octahedron. Differential scanning calorimetry and thermogravimetric-differential thermogravimetric analysis were applied to assess the thermal decomposition behavior. The kinetic parameters were obtained by non-isothermal reaction kinetics. The equation can be expressed as . Moreover, the values of critical temperature of thermal explosion, ΔS≠ , ΔH≠ , ΔG≠ , and the energy of combustion were obtained as 284°C, −169.76 J mol−1 K−1, 65.46 kJ mol−1, 154.27 kJ mol−1, and 6759 kJkg−1, respectively.

Synthesis of fluorescent coumarin triazolylglycosides

A series of coumarin triazolylglycosides were synthesized in good yields using copper-mediated 1,3-dipolar cycloaddition reactions of carbohydrate azides and 4-alkynyl-substituted coumarins. Several of the products show strong luminescence in the 490–560nm region and are compatible with surface imaging applications.