masoud mokhtary

In this research, we present an effective method for synthesizing new derivatives of ethyl cyanoacetate throughbase-free Knoevenagel condensation using ellagic acid-bonded magnetic nanoparticles (nano-Fe3O4@EA) asa catalyst. This method offers several advantages, including high yield, short reaction time, and simplicity,making it an attractive and efficient option in the emerging field of Knoevenagel condensation.

This review delves deeply into the biological effects of heterocycles containing N‒O bonds, exploring their possible roles in drug discovery and development. The goal of this study is to investigate the biological activity of certain compounds by analyzing their structural and electronic characteristics. The focus will be on examining the relationship between the chemical structure of heterocycles with N–O bonds and their potential effects on biological systems. By studying how these compounds interact with biological targets, researchers hope to uncover the molecular mechanisms underlying their pharmacological properties. This review also discusses the theoretical and computational methods used to study the biological effects of N–O bond-containing heterocycles, highlighting the significance of theoretical modeling in drug development. Additionally, potential applications of N‒O bonds in cancer treatment, antimicrobial activity, and neurodegenerative disorders will be explored. This study aims to bridge the gap between theory and practice and provide insights into the design of bioactive compounds with enhanced pharmacological characteristics. Challenges and future directions in this field are discussed, stressing the importance of ongoing research and innovation in medicinal chemistry.

In the present work, a polyetherimide/ZIF-8 composite membrane was fabricated by solution casting technique. The prepared membranes were Characterized using Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy – attenuated total reflectance (FTIR-ATR), energy dispersive X-ray (EDAX) and X-ray diffraction (XRD). Furthermore, the membrane's performance in separating carbon dioxide and methane was analyzed through single gas permeability measurements. FTIR-ATR spectrum of the prepared membrane confirmed the functional groups of polyetherimide. XRD analysis showed that the additive was well dispersed in the polymer, resulted in a reduction in the membrane's crystallinity. EDAX analysis confirmed the existence and proper dispersion of Zn particles in the membrane. Finally. The results of permeability tests showed that adding ZIF-8 to the membrane significantly increased its permeability and selectivity. The permeability of the composite membrane for CO2 gas was 5.91 GPU, more than twice that of the pure polyetherimide membrane. Additionally, the permeability for CH4 gas was 0.31 GPU, representing a significant improvement over the pure membrane's permeability of 0.17 GPU. The carbon dioxide/methane selectivity also rose from 15.3 in the pure membrane to 19.1 in the composite membrane. In conclusion, the study demonstrated that adding ZIF-8 to a polyetherimide matrix can improve the effectiveness of the resulting composite membrane for separating CO2 from CH4. The improvement in selectivity was primarily due to the increased solubility coefficient of carbon dioxide compared to methane in the composite membrane.

In the present work, a polyetherimide/ZIF-8 composite membrane was fabricated by solution casting technique. The prepared membranes were Characterized using Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy – attenuated total reflectance (FTIR-ATR), energy dispersive X-ray (EDAX) and X-ray diffraction (XRD). Furthermore, the membrane's performance in separating carbon dioxide and methane was analyzed through single gas permeability measurements. FTIR-ATR spectrum of the prepared membrane confirmed the functional groups of polyetherimide. XRD analysis showed that the additive was well dispersed in the polymer, resulted in a reduction in the membrane's crystallinity. EDAX analysis confirmed the existence and proper dispersion of Zn particles in the membrane. Finally. The results of permeability tests showed that adding ZIF-8 to the membrane significantly increased its permeability and selectivity. The permeability of the composite membrane for CO2 gas was 5.91 GPU, more than twice that of the pure polyetherimide membrane. Additionally, the permeability for CH4 gas was 0.31 GPU, representing a significant improvement over the pure membrane's permeability of 0.17 GPU. The carbon dioxide/methane selectivity also rose from 15.3 in the pure membrane to 19.1 in the composite membrane. In conclusion, the study demonstrated that adding ZIF-8 to a polyetherimide matrix can improve the effectiveness of the resulting composite membrane for separating CO2 from CH4. The improvement in selectivity was primarily due to the increased solubility coefficient of carbon dioxide compared to methane in the composite membrane.

In this study, the preparation of a new functionalized acidic metal-organic framework nanocatalyst formulated as Zr-MOF-N=CH-C6H4-SO3H has been reported. After characterization using different analysis methods such as FT-IR, XRD, SEM, EDX, TGA, and TEM, the average size of the nanoparticles was found to be between 42.5 and 50.4 nm in diameter. The Nanocatalyst was utilized in the synthesis of novel substituted 4-aminocoumarin analogs via one-pot three-component reaction of 4-aminocoumarin, arylaldehyde or 3-(2-aryldiazenyl)-2-hydroxybenzaldehyde, and 6-hydroxyuracil or 1,3-dimethylbarbituric acid in good-to-excellent yields in ethanol at reflux conditions. A λmax of 362.7 nm was observed for compound 4e. Simple work-up of the process, mild reaction conditions, no by-products and easy reusability of the nanocatalyst are some of the advantages of the procedure. Highlights  ·A novel series of substituted 4-aminocoumarin analogs were synthesized.A new functionalized acidic metal-organic framework catalyst Zr-MOF-N=CH-C6H4-OSO3H was introduced.· High yields and easy work-up procedure are some advantages of this method.·A λmax of 362.7 nm was observed for compound 4e.The catalyst is easily recycled.

In this work, gelatin-polyvinylalcohol hydrogel was prepared using K2S2O8 in aqueous media in the presence of N,N′-methylenebisacrylamide. The gelatin-polyvinylalcohol hydrogel was characterized by FT-IR, SEM and swelling studies. Then, loading and release of fluvoxamine maleate drug was investigated using gelatin-polyvinylalcohol hydrogel. The effects of temperature and pH on the loading and release of fluvoxamine maleate drug in gelatin-polyvinylalcohol hydrogel were studied. FT-IR results confirmed the formation of gelatin and polyvinyl alcohol hydrogel. The results showed that the maximum drug release was obtained at pH = 2 at room temperature after 6 hours with a value of 43.98 ppm. Gelatin-polyvinyl alcohol hydrogel shows about 11 times water absorption at room temperature. The gelatin-polyvinyl alcohol hydrogel is sensitive to pH and temperature and provides controlled release of fluvoxamine maleate in the gastric environment.

In this work, an efficient method for the construction of N-amino-2-pyridone analogs was performed using the condensation of aldehyde, malononitrile and cyanoacetohydrazide through Fe3O4@aminopropyltriethoxysilane-terephthaldehyde-melamine (Fe3O4@APTES-TA-MA) as an efficient recyclable magnetic covalent organic framework nanocatalyst in ethanol at reflux conditions. Fe3O4@APTES-TA-MA was characterized via FT-IR, EDS, SEM, TEM, VSM, and TGA methods. The average size of the nanoparticles was found between 40-90 nm. Clean procedure, short reaction time, and high efficiency are some benefits of this protocol. Also, the nanomagnetic catalyst can be reused five times without significant loss of its activity.

The development of novel techniques for the efficient construction of heterocyclic compounds is an major issue in the preparation of organic compounds. The piperidine building block acts as a substantial task in the inhibitory activity of compounds and thus is very important in influencing biological properties such as antioxidant, anti-Alzheimer and free radical scavenging activities. Highly substituted piperidine analogs play a remarkable role in the synthesis of pharmaceutical compounds as important structural components in active and natural biological compounds. This review summarized advances in the synthesis of highly substituted piperidine analogs and their antioxidant and anti-Alzheimer properties. Antioxidant activities are inversely proportional to IC50 value. In addition, new green methods for the preparation of piperidine building blocks, such as: non-toxic catalysis, water-initiated processes, solvent-free reactions, etc., are also presented. This review study is designed to assist scientists looking for suitable substrates for the construction of biologically active piperidine analogs.

In this review paper, a systematic study on the physical adsorption of ionic liquids with different cations, investigation of molecular interactions between cations and anions of tunable ionic liquids, study of different nanostructures based on graphene, silicon, germanium and boron-nitride without defects and comparison of stability between types of nanostructures and creating defects on them (pore defects and Stone Walls) and studying the effect of changes in the absorption of ionic liquids on different nanostructures without defects and defects on physical properties such as: bond energy, interaction energy, energy gap, chemical hardness, chemical potential and absorption spectra have been performed.

Extensive biological activities associated with xanthenes, both synthetic and naturally occurring, ensure that the synthesis of these compounds remains a topic of current interest. In this research, an efficient methods for the synthesis of some bulky xanthenediones was developed by the reaction of dimedone or 1,3-cyclohexadione with aledydes or bisaldehydes in the presence of polyvinylpolypyrrolidone supported p-toluene sulfonic acid (PVPP-p-TSA) as a new polymeric catalyst in ethanol at room temperature. Forthermore, a convenient method for the synthesis of (arylmethylene)bis(naphthalene-2-yl-sulfane) derivatives by polyvinylpolypyrrolidone supported p-toluene sulfonic acid (PVPP-p-TSA) is described. The reaction proceeded via condensation of aldehydes with 2-thionaphthol in the presence of PVPP-p-TSA in ethanol at reflux conditions. All synthesized compounds were identified by FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques. Polyvinylpolypyrrolidone supported p-toluene sulfonic acid (PVPP-p-TSA) was characterized via Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Clean methodologies, simple preparation of the catalyst, high yields, environment-friendly and reusable catalyst are some advantages of this work.

In this study, graphene oxide immobilized on chitosan contains cobalt ferrite (CoFe2O4@CS@GO) as a new recyclable magnetic nabnocatalyst was used in the synthesis of bis(aminopyrimidine) derivatives by the reaction of aromatic aldehydes and 6-aminouracil in ethanol with good to excellent yields under reflux conditions. The CoFe2O4@CS@GO catalyst can be easily recovered by magnetic separation and used several times without significantly reducing its catalytic activity. The catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDs) and vibrating sample magnetometer (VSM).The high efficiency of the products and easy separation of the nanocatalyst from the products with external permanent magnet are some advantages of this method. Products were identified by the comparison of their physical properties and spectra data, with those reported for authentic samples.

Clinical interest in metabolic imaging of cancer has been growing in recent years. The increase in protein metabolism of cancer cells is interesting target for metabolic tumor imaging, for which radiolabeled amino acids can be applied. The aim of this study was to evaluate a newly developed radiolabeled amino acid as an imaging protein metabolism in melanoma tumor.

The radiolabeled tyrosine ([99mTc][Tc-HYNIC/EDDA]-Tyr) was prepared and its biological  properties was evaluated in B16F10 melanoma tumor. Moreover organs uptake and tumor accumulation were measured in mouse bearing B16F10 melanoma tumor.

Radiolabeled tyrosine was attached in B16F10 melanoma cells and showed the cell binding capacity of 13.82±0.73%. In animal study, the accumulation of radiolabeled tyrosine was observed in B16F10 melanoma tumor (2.15±0.09 %ID/g) after 30 min post injection, so that the uptake ratio of tumor to muscle was about 5.11. Through scintigraphy process the melanoma tumor clearly visualized in mice at 30 min post injection.

These data suggest that the novel radiotracer ([99mTc][Tc-HYNIC/EDDA]-Tyr) as an protein metabolism imaging agent, is able to transfer into melanoma cells and show great expectation for the clinical application in the imaging of melanoma tumors.

Consideration for the development of new methods for the efficient preparation of heterocyclic compounds is an important issue in the synthesis of organic compounds in chemistry. The benzo[b]pyrans and pyranopyrazoles are important heterocyclic compounds that constitute the structural unit of a series of important natural biological products. In this research, ammonium fluoride was successfully applied to perform a one-pot reaction of aryl aldehydes, dimedone, or 1,3-cyclohexadione and malononitrile in EtOH:H2O (1:1) at room temperature to provide a series of tetrahydrobenzo[b]pyrans in excellent yields. Furthermore, ammonium fluoride catalyzed four-component condensations of aldehyde, malononitrile, hydrazine hydrate, and ethyl acetoacetate to synthesize pyranopyrazole derivatives in EtOH:H2O (1:1) at 80 °C. Clean methodologies, short reaction time, high yields, cost-effective catalysts, non-toxic, and environmentally friendly solvent are some advantages of this research. All products were characterized by spectral data and by comparison with authentic samples reported in the literature.

The development of new methods for the efficient preparation of heterocyclic compounds is an important issue in the synthesis of organic compounds in chemistry. Chromene derivatives play a considerable role in the synthesis of pharmaceutical compounds as a significant structural component in active and natural biological compounds. In this research, 3-carboxy-1-sulfopyridinium chloride ([NA-SO3H]+Cl-) was evaluated as a recoverable catalyst for the one-pot synthesis of dihydrochromenochromene derivatives by reaction of aryl aldehydes, 1,3-cyclohexanediones, and hydroxycoumarines in good to excellent yields in ethanol at 70 °C. The [NA-SO3H]+Cl- could be recycled several times without significant loss of its catalytic activity. Clean methodologies, easy work-up procedures, high yield, and simple preparation of the catalyst are some advantages of this procedure. All products were characterized by spectral data and by comparison with authentic samples reported in the literature.

White rice husk ash (RHA), an agricultural waste, was used as a silica source forMTW zeolite synthesis. The RHA-MTW zeolite derived from RHA was preparedby hydrothermal method at 150 °C in the presence of tetraethylammoniumhydroxide. ZnO nanoparticles (NPs) were grown in zeolite substrates using asolid state reaction. The synthesized nanocomposite (NC) was characterized byXRD, SEM, DRS and TEM and tested as photocatalytic degradation of methyleneblue (MB) dye from aqueous solution under ultraviolet (UV) light. The BET resultsindicated that pore volume and surface area of ZnO/RHA-MTW NC was smallerthan RHA-MTW zeolite. On the basis of the obtained experimental results, it wasfound that zinc oxide NPs were encapsulated into the channels of RHA-MTWzeolite. The SEM and TEM images of ZnO/RHA-MTW NC confirmed the formationof RHA-MTW particles with size diameter of 2.5 μm and locating of zinc oxideNPs in channels of zeolite with an average size of between 35 nm. The resultsshowed MB degradation had reached 85 % under UV light. The MB indicatedmaximum adsorption at pH=9. The photocatalytic activity of ZnO was enhancedin the presence of zeolite due to reduction of recombination rate of the electrohole in ZnO semiconductor.ARTICLE INF O

Unripe grape juice (verjuice) as a natural catalyst was successfully applied to perform the one-pot reaction of aryl aldehydes, malononitrile, hydrazine hydrate and ethyl acetoacetate to synthesize pyranopyrazole derivatives in aqueous ethanol at room temperature in excellent yields. Furthermore, unripe grape juice catalyzed one-pot synthesis of hexahydroquinoline-3-carboxamide derivatives by the four-component reaction of arylaldehydes, dimedone, acetoacetanilide and ammonium acetate in high to excellent yield in ethanol at 70 ℃. The synthesized compounds were identified by FT-IR, 1H NMR and 13C NMR spectroscopic techniques and elemental analysis. An environmentally benign procedure, short reaction time, high yields and biocompatible natural catalyst are some advantages of this research.

An efficient synthesis of chromenylphenylpropanone derivatives as warfarine-like analogues was developed by the Michael addition of 4-hydroxycoumarin to α,β-unsaturated compounds in the presence of polyvinylpolypyrrolidone supported antimony(III) chloride (PVPP-SbCl3) as a new polymeric Lewis acid catalyst in chloroform at reflux conditions without formation of 2,4-diarylpyrano[3,2-c]chromen-5(4H)-ones. The synthesized compounds were identified by FT-IR, 1HNMR and 13CNMR spectroscopic techniques and elemental analysis. Polyvinylpolypyrrolidone supported antimony(III) chloride was characterized via Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Clean methodologies, simple preparation of the catalyst, good yields, environmentally friendly and reusable catalyst are some advantages of this work.

Polyvinylpyrrolidone (PVP)/carboxyl functionalized multiwalled carbon nanotube (MWCNT-COOH) nanocomposite was prepared in aqueous media. The structure, morphology, and thermal characterization of PVP/MWCNT-COOH nanocomposite were done by FT-IR, SEM, TGA and DSC techniques. According to the DSC analysis, the glass transition temperature of 159 °C is observed for PVP/MWCNT-COOH (5% w/w). The addition of MWCNT-COOH (5% W/W) to PVP increases the thermal stability of PVP to 400 °C which was indicated in TGA thermogram.The FT-IR spectra showed the hydrogen bonding has been takes place between MWCNT-COOH and PVP in the PVP/MWCNT-COOH (5% w/w) nanocomposite. The SEM images of the PVP/MWCNT-COOH (5% w/w) nanocomposite clearly exhibited the presence of MWCNT-COOH in PVP polymer matrix.

Polyvinylpolypyrrolidone supported chlorosulfonic acid ([PVPP-SO3H]) was synthesized and evaluated as a recoverable catalyst for the one-pot synthesis of hexahydroquinolines by reaction of arylaldehydes, dimedone (5,5-dimethylcyclohexane-1,3-dione) or 1,3-cyclohexanedione, ethylacetoacetate and ammonium acetate in high to excellent yield in ethanol at 70 °C. The [PVPP-SO3H] catalyst was characterized via Fourier transform infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA). The capacity of the reagent was determined by titration and found to be 12 mmol/g, which shows a high loading of H per gram of the catalyst. Moreover, the catalyst could be recycled several times without significant loss of its catalytic activity. Clean methodologies, easy work-up procedure, high yield and simple preparation of the catalyst are some advantages of this work.

The direct three component modified Mannich reaction via condensation of aldehydes, 2-naphthol or 2,7-naphthalendiol and piperidine to generate Betti bases has been carried out over L-proline (20 mol%) with high efficiency under solvent free conditions at 70 OC. Also, the reaction of aromatic aldehyde and 4-hydroxycoumarin in the presence of L-proline (20 mol%) in the ethanol under reflux conditions, lead to biscoumarin derivatives

Highly efficient method for the preparation of N-tert-butyl amides by reaction of nitriles with tertbutylacetate is described using boron trifluoride etherate in solvent free condition. Selective amidation of benzonitrile in the presence of acetonitrile was also achieved.

Cross-linked poly(vinyl alcohol)/poly(vinyl pyrrolidone) (PVP/PVA) hydrogels were prepared in aqueous media using K2S2O8. The gel fraction, degree of swelling in water, and mechanical properties, such as TGA, DSC, and tensile strength were measured. It was found that the gel fraction increases with increasing potassium peroxodisulphate concentration but never reach to 100%. The swelling behaviour of the gels were specified by a relatively fast rate of swelling at the beginning of the process and measured as gram of water per minute. The amount of absorbed water as immersion water uptake of greater than 1400% is obtained. Because of the neutrality of the hydrogels, the maximum of swelling was achieved at pH=7. Maximum extents of swelling were achieved at 25oC and the swelling of hydrogels was found to decrease at higher temperatures. The hydrogel could be considered as a good barrier against common microbes including Sarcina lutea, Escherichia Coli, and Pesudomonase aeruginosa. The thermal analysis shows that the gels are stable up to 350oC. According to the DMTA thermogram, the glass temperature of 44.8°C is observed for 50 % w/w of hydrogel sample. Tensile strength as high as 90.8-10.0 Kg/cm2 and elongation-at-break about 60% were achieved using 1.1×10-5 M concentration of KPS