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1.
Molybdate sulfonic acid (MSA) as a highly efficient catalyst was synthesized and employed for the synthesis of octahydroxanthene-1,8-dione derivatives. MSA efficiently catalyzed condensation of a wide range of aryl aldehydes and cyclohexane-1,3-diones to obtain octahydroxanthene-1,8-diones. It was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), and FT-IR spectroscopy. This catalyst can be recovered and reused several times in other reactions maintaining its high activity. This novel and green method is very cheap and has many advantages such as excellent yields, the use of recoverable and eco-friendly catalysts, and a simple work-up procedure.  相似文献   

2.
In this protocol, Ag supported on the hydroxyapatite-core–shell magnetic γ-Fe_2O_3nanoparticles(γFe_2O_3@HAp-Ag NPs) as a novel, efficient, and magnetically recyclable catalyst is synthesized, and characterized by transmission electron microscopy(TEM), scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD), and vibrating sample magnetometry(VSM). The use of the catalyst is described in the synthesis of coumarin derivatives by the Pechmann condensation of various phenols with β-ketoesters under solvent- and halogen-free conditions at 80℃.This novel and inexpensive method offers advantages, such as recyclability simple experimental protocol, short reaction time, minimal work-up procedure, and excellent yields of products, together with desirable, eco-friendly, green aspects by avoiding toxic elements and solvents, and ease of recovery from the reaction mixture using an external magnet.  相似文献   

3.
In the present study, we developed an eco-friendly method of stable silver nanoparticles (AgNPs) production using the aqueous extract of Trichodesmium erythraeum. The biosynthesized AgNPs were characterized using UV–Vis spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Energy-Dispersive X-ray (EDX), and X-ray diffraction (XRD). The results affirmed that synthesized AgNPs were crystalline in nature, cubical in shape, and the average size of T. erythraeum silver nanoparticles (TENPs) was 26.5 nm. The antioxidant potential of synthesized AgNPs (500 µg/ml) was 77.01 ± 0.17% in DPPH, 67.5 ± 0.22% in Deoxy-ribose, 52.77 ± 0.42% in ABTS and 88.12 ± 0.26% in nitric oxide radical scavenging assays. The antibacterial results showed excellent inhibition against the clinical strains (Staphylococcus aureus and Proteus mirabilis) and drug-resistant bacterial strains such as E. coli (AmikacinR), S. aureus (TetracyclineR) and S. pneumoniae (PenicillinR). The maximum anti-proliferative effect of TENPs was seen using 50 µg concentration against He La and MCF-7 cell lines, and IC50 values were 25.0 ± 0.50 µg/ml and 30.0 ± 0.50 µg/ml, respectively, at 24 h.  相似文献   

4.
We described a novel and eco-friendly approach to remove toxic heavy metal of Pb(II) by using dimercaptosuccinic acid (DMSA) anchored Fe3O4 magnetic nanorods (MNRs) which were synthesized via facile method utilizing Punica Granatum rind extract which was a non toxic waste material. The DMSA@Fe3O4 MNRs were characterized by X-ray diffraction (XRD), Fourier transformed infrared analysis (FT-IR), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), nitrogen adsorption and desorption techniques, and vibrating sample magnetometer (VSM). These DMSA@Fe3O4 MNRs have been used for the removal of Pb(II) from aqueous solution. The adsorption isotherm data fitted well with Langmuir isotherm and Freundlich model, the monolayer adsorption capacity was found to be 46.18 mg/g at 301 K. The experimental kinetic data fitted very well with the pseudo-second-order model. The results indicate that the biogenic synthesized DMSA@Fe3O4 MNRs act as significant adsorbent material for removal of Pb (II) from aqueous environment.  相似文献   

5.
Highly efficient synthesized magnetic cobalt ferrite nanoparticles supported on OCMC@Cu (BDC) was utilized in the preparation of biologically active heterocyclic compounds through one-pot three-component reactions between of aldehydes, dimedone, aryl amines/2-naphthol/urea under ultrasonic irradiation. This method has various advantages including excellent yields, little catalyst loading, simple procedure, facile catalyst separation, short reaction times, eco-friendly approach and simple purification. The catalyst was characterized by various spectroscopy methods such as fourier-transform infrared (FT-IR), energy-dispersive X-ray (EDX), scanning electron microscope (SEM), X-ray diffraction (XRD) and N2 adsorption–desorption isotherm (BET). Furthermore, the heterocyclic compounds were characterized by spectral techniques. The nanocomposite was simply separated byusing an external magnet, and it can be recycled several times without significant loss of activity.  相似文献   

6.
The ability of microorganisms to reduce inorganic metals has launched an exciting eco-friendly approach towards developing green nanotechnology. Thus, the synthesis of metal nanoparticles through a biological approach is an important aspect of current nanotechnology. In this study, Streptomyces aizuneusis ATCC 14921 gave the small particle of silver nanoparticles (AgNPs) a size of 38.45 nm, with 1.342 optical density. AgNPs produced by Streptomyces aizuneusis were characterized by means of UV-VIS spectroscopy and transmission electron microscopy (TEM). The UV-Vis spectrum of the aqueous solution containing silver ion showed a peak between 410 to 430. Moreover, the majority of nanoparticles were found to be a spherical shape with variables between 11 to 42 nm, as seen under TEM. The purity of extracted AgNPs was investigated by energy dispersive X-ray analysis (EDXA), and the identification of the possible biomolecules responsible for the reduction of Ag+ ions by the cell filtrate was carried out by Fourier Transform Infrared spectrum (FTIR). High antimicrobial activities were observed by AgNPs at a low concentration of 0.01 ppm, however, no deleterious effect of AgNPs was observed on the development and occurrence of Drosophila melanogaster phenotype. The highest reduction in the viability of the human lung carcinoma and normal cells was attained at 0.2 AgNPs ppm.  相似文献   

7.
基于化学氧化聚合法制备了粒径约为40nm的掺杂对甲苯磺酸(TSA)的聚吡咯(PPy)复合纳米粒子.采用XRD、EDS、SEM和TEM研究了产物的结构和形貌特征,并用循环伏安、恒流充放电等方法测试了纳米粒子的电化学性能.结果表明PPy/TSA具有良好的快速充放电能力,在10 mA/cm2时比容量达到268Fg-1,但在1000次循环后发现其比容量下降了25.5%.用CV测试了PPy/TSA电极在第一次循环和第1000次循环的伏安曲线图,发现经过1000次循环后PPy/TSA电极的氧化峰逐渐消失,并且非法拉第电流减小.交流阻抗测试表明,PPy/TSA纳米粒子在反复充放电循环后,其界面电荷传递电阻增加,高频段双层电容值降低,但低频段的赝电容值却有所增加.通过比表面积测量发现,聚合物链的反复氧化-还原过程还可导致平均孔径减小、比表面积下降.红外和拉曼光谱也证实PPy纳米粒子在充放电过程中会发生降解,生成一种含氧的醌式结构,这表明聚合物电极材料比容量的下降可能与PPy主链的不可逆氧化和结构碎片化有关.  相似文献   

8.
Green synthesis of silver nanoparticles (AgNPs) employing an aqueous plant extract has emerged as a viable eco-friendly method. The aim of the study was to synthesize AgNPs by using plant extract of Sanvitalia procumbens (creeping zinnia) in which the phytochemicals present in plant extract act as a stabilizing and reducing agent. For the stability of the synthesized AgNPs, different parameters like AgNO3 concentration, volume ratios of AgNO3, temperature, pH, and contact time were studied. Further, AgNPs were characterized by UV–visible spectroscopy, FT-IR (Fourier Transform Infrared Spectroscopy), XRD (X-ray Diffraction), SEM (Scanning Electron Microscopy), and EDX (Energy Dispersive X-ray Spectrometer) analysis. FT-IR analysis showed that the plant extract contained essential functional groups like O–H stretching of carboxylic acid, N–H stretching of secondary amides, and C–N stretching of aromatic amines, and C–O indicates the vibration of alcohol, ester, and carboxylic acid that facilitated in the green synthesis of AgNPs. The crystalline nature of synthesized AgNPs was confirmed by XRD, while the elemental composition of AgNPs was detected by energy dispersive X-ray analysis (EDX). SEM studies showed the mean particle diameter of silver nanoparticles. The synthesized AgNPs were used for photocatalytic degradation of Orange G and Direct blue-15 (OG and DB-15), which were analyzed by UV-visible spectroscopy. Maximum degradation percentage of OG and DB-15 azo dyes was observed, without any significant silver leaching, thereby signifying notable photocatalytic properties of AgNPs.  相似文献   

9.
Potential effects of tea and its constituents on SARS-CoV-2 infection were assessed in vitro. Infectivity of SARS-CoV-2 was decreased to 1/100 to undetectable levels after a treatment with black tea, green tea, roasted green tea, or oolong tea for 1 min. An addition of (−) epigallocatechin gallate (EGCG) significantly inactivated SARS-CoV-2, while the same concentration of theasinensin A (TSA) and galloylated theaflavins including theaflavin 3,3′-di-O-gallate (TFDG) had more remarkable anti-viral activities. EGCG, TSA, and TFDG at 1 mM, 40 µM, and 60 µM, respectively, which are comparable to the concentrations of these compounds in tea beverages, significantly reduced infectivity of the virus, viral RNA replication in cells, and secondary virus production from the cells. EGCG, TSA, and TFDG significantly inhibited interaction between recombinant ACE2 and RBD of S protein. These results suggest potential usefulness of tea in prevention of person-to-person transmission of the novel coronavirus.  相似文献   

10.
Nowadays, the industrial wastewater pollutants including toxic dyes and pathogenic microbes have caused serious environmental contaminations and human health problems. In the present study, eco-friendly and facile green synthesis of Ag modified ZnO nanoparticles (ZnO-Ag NPs) using Crataegus monogyna (C. monogyna) extract (ZnO-Ag@CME NPs) is reported. The morphology and structure of the as-biosynthesized product were characterized by field emission scanning electron microscopy (FESEM), X-Ray diffraction (XRD), differential reflectance spectroscopy (DRS), dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDS) techniques. TEM and FESEM images confirmed the oval and spherical-like structure of the products with a size of 55–70 nm. The EDS analysis confirmed the presence of Zn, Ag, and O elements in the biosynthesized product. The photocatalytic results showed ZnO-Ag@CME NPs were degraded (89.8% and 75.3%) and (94.2% and 84.7%) of methyl orange (MO) and basic violet 10 (BV10), under UV and sunlight irradiations, respectively. The Ag modified ZnO nanoparticles exhibited enhanced catalytic activity towards organic pollutants, and showed better performance than the pure ZnO nanoparticles under UV and sunlight irradiations. This performance was probably due to the presence of silver nanoparticles as a plasmonic material. Antibacterial activity was performed against different bacteria. ZnO-Ag@CME NPs showed high antibacterial activity against K. pneumoniae, S. typhimurium, P. vulgaris, S. mitis, and S. faecalis with MIC values of 50, 12.5, 12.5, 12.5, and 12.45 µg/mL, respectively. All in all, the present investigation suggests a promising method to achieve high-efficiency antibacterial and catalytic performance.  相似文献   

11.
《Tetrahedron letters》1988,29(34):4241-4244
A novel furanoid bisnorditerpene has been isolated from the fresh stems of Tinospora malabarica Miers (Menispermaceae) and structurally characterized using X-ray crystallographic and spectroscopic techniques.  相似文献   

12.
A novel approach for the synthesis of N-1 substituted thiohydantoin has been developed to give quantitative yields of the desired products. The efficient synthesis of bis-thiohydantoin derivative and bicyclothiohydantoin has extended scope and applicability of present method. Solvent-free conditions and very easy work-up procedure make the reaction convenient and eco-friendly. All the products were characterized by spectroscopic techniques and elemental analysis, and finally the structure of representative compound was also confirmed by X-ray crystallography.  相似文献   

13.
In this work, L-lysine-Pd Complex, immobilized onto the surface of Fe3O4 MNPs, was successfully prepared via simple and inexpensive procedure. The prepared nanocatalyst was considered as a robust and clean nano-reactor catalyst for the Suzuki and Heck C-C Cross-Coupling reactions in water as the green condition. This eco-friendly heterogeneous catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), X-Ray Diffractometer (XRD), energy-dispersive X-ray spectroscopy (EDS), inductively coupled plasma atomic emission spectroscopy (ICP), X-ray mapping, BET, thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) techniques. The use of a green medium, easy separation and workup, excellent reusability of the nanocatalyst and short reaction time are some outstanding advantages of this method.  相似文献   

14.
The synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives by NiCl2-catalyzed novel one-pot four-component condensation reaction of phthalimide, hydrazine, malononitrile (or ethyl cyanoacetate), and aromatic aldehydes was reported. This work provides a simple, efficient, and eco-friendly method for the construction of pyrazolo[1,2-b]phalazine-5,10-dione derivatives.  相似文献   

15.
In this study, an eco-friendly and low-cost procedure for the in situ fabrication of Cu nanoparticles by using chitosan/alginate hydrogel. The prepared Cu NPs@CS/Alg nanocomposite were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) study. It has been established that chitosan/alginate-capped gold nanoparticles have a spherical shape with a mean diameter from 10 to 20 nm. In the cellular and molecular part of the recent study, the treated cells with Cu NPs@CS/Alg nanocomposite were assessed by MTT assay for 48 h about the cytotoxicity and anti-human breast cancer properties on normal (HUVEC) and breast cancer cell lines i.e. infiltrating lobular carcinoma of breast (UACC-3133), inflammatory carcinoma of the breast (UACC-732), and metastatic carcinoma (MDA-MB-453). In the antioxidant test, the IC50 of Cu NPs@CS/Alg nanocomposite and BHT against DPPH free radicals were 344 and 193 µg/mL, respectively. The IC50 of Cu NPs@CS/Alg nanocomposite were 297, 386, and 359 µg/mL against KYSE-270, OE33, and ESO26 cell lines, respectively. The viability of malignant breast cell line reduced dose-dependently in the presence of Cu NPs@CS/Alg nanocomposite.  相似文献   

16.
Stable silver nanoparticles were synthesized with the aid of a novel, non-toxic, eco-friendly biological material namely, green pepper extract. The aqueous pepper extract was used for reducing silver nitrate. The synthesized silver nanoparticles were analyzed with transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). TEM image shows the formation of silver nanoparticles with average particle size of 20 nm which agrees well with the XRD data. The main advantage of using pepper extract as a stabilizing agent is that it provides long-term stability for nanoparticles by preventing particles agglomeration. To investigate the electrocatalytic efficiency of silver nanoparticles, silver nanoparticles modified carbon-paste electrode (AgNPs–CPE) displayed excellent electrochemical catalytic activities towards hydrogen peroxide (H2O2) and hydrogen evolution reaction (HER). The reduction overpotential of H2O2 was decreased significantly compared with those obtained at the bare CPE. An abrupt increase of the cathodic current for HER was observed at modified electrode. Also, the antibacterial activity of silver nanoparticle was performed using Escherichia coli and Salmonellae. The approach of plant-mediated synthesis appears to be cost efficient, eco-friendly and easy methods.  相似文献   

17.
In this study, an eco-friendly and low-cost procedure for the synthesis of White tea plant extract modified magnetic nanocomposite (Fe3O4@W.tea) has been demonstrated. Ag nanoparticles (Ag NPs) were further decorated in situ over the designed Fe3O4@W.tea nanocomposite exploiting the plant derived phytochemicals as bio-reductant and stabilizer. The resulting Fe3O4@W.tea/Ag nanocomposite was characterized by various analytical methods like Fourier Transformed Infra Red (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), energy dispersive X-ray analysis (EDX) elemental mapping, transmission electron microscopy (TEM), vibrating-sample magnetometer (VSM), X-ray diffraction analysis (XRD), and inductively coupled plasma-atomic emission spectrometry (ICP-AES) analysis. The as-synthesized bio-nanomaterial was used as an excellent heterogeneous and magnetically retrievable catalyst in the three-component condensation of 4-hydroxycoumarin, malononitrile and various aldehydes in refluxing aqueous media. A broad range of aromatic aldehydes underwent the reaction to produce diverse pyrano[3,2-c]chromene derivatives in very good yields irrespective of the nature of bearing functional groups or their respective geometrical positions. Due to superparamagnetic character, the material was easily magnetically decanted out and recycled for 8 successive times with preservation of its catalytic activity. After the chemical applications we also explored the material biologically in the resistance of human colon cancer and thereby studied the cytotoxicity over two standard cell lines, HT-29 and Caco-2. The conventional MTT assay was carried out over them which revealed an increase in % cell viability dose dependently. The IC50 values observed in the two cell lines were 384.2 μg/ml and 254.6 μg/ml respectively. In addition, DPPH radical scavenging test was performed for studying anti-oxidant activity. The results validate the administration of Fe3O4@W.tea/Agnanocomposite as a competent colon protective drug in the clinical trial studies over human.  相似文献   

18.
The development of highly efficient adsorbents materials for the purification of wastewater has caught a considerable deal of attention these days. Conducting polymers functionalized adsorbents has become a favorable route for enhancing their adsorption capability due to their ease of synthesis at laboratory scale. In this study, functionalized multiwalled carbon nanotube (CNT)-polyaniline (Pani) composites were fabricated using an oxidation polymerization methodology and later doped with para toluene sulfonic acid (pTSA). The CNTs provided an adequate substrate for the adhesion of Pani as well as a large surface area due to its nano size, and pTSA provided additional functionality for the adsorption of differently charged moieties through strong or weak interactions. The as-synthesized pTSA-Pani@CNT nanocomposite was analyzed by the scanning electron microscopy, transmission electron microscopy for the morphological studies and the structural analysis were done by the X-ray diffraction, and X-ray photoelectron spectroscopy (XPS). The characterization results confirmed that the Pani was adhered to the CNTs as well as its successful functionalization with pTSA. The pTSA-Pani@CNT composite was then applied to the adsorptive removal of hexavalent chromium (Cr(VI)) and the composite showed higher adsorption for Cr(VI) than pTSA-CNT and pTSA-Pani, and the maximum removal level was detected at acidic pH. The analyses of the equilibrium isotherms and adsorption kinetics were performed to elucidate the adsorption mechanism. The XPS analysis indicated that Cr(VI) was strongly bounded to the adsorbent and it further indicated that the amine, imine, and hydroxyl functional groups were involved in the adsorption process. This study presents a new insight for the fabrication of highly functional polymer-carbonaceous nanocomposites for the scavenging of heavy metals from water bodies.  相似文献   

19.
The present work focused on the utilization of Egyptian red clay (ERC) without any treatment as a highly efficient, selective, and eco-friendly catalyst for synthesis of bio-ethyl acetate in the gas phase. The best conditions used in conventional fixed bed reactor were 130 cm3/min total flow rate of air with 1.6 and 2.1 vol% bio-ethanol and bio-acetic acid, respectively, 1 g clay catalyst calcined at 300 and 225°C reaction temperature. Under these conditions, the conversions to ester achieved were about 80 and 98% after 5 and 30 min, respectively, from the initial admission of the reactants into the reactor. The amount and type of surface acidity were identified by isopropanol reaction and chemisorption of basic probes. The results demonstrated that the majority of intermediate strength of BrØnsted acid sites are the key role for the dehydration reaction toward ester formation. The virgin and annealed clay solids were characterized using X-ray fluorescence (XRF), thermogravimetry (TG) and differential thermal analysis (DTA), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and N2 sorption.  相似文献   

20.
The purpose of the research was to examine the protective effect of essential oil from Thymus serrulatus Hochst. ex Benth. (TSA oil) against cadmium (Cd)-induced renal toxicity. The experimental protocol was designed using 30 healthy adult Wistar albino rats allocated into five groups containing six animals in each group. Group 1 was treated as normal control and groups 2, 3, 4, and 5 were treated with cadmium chloride (CdCl2, 3 mg/kg, IP) for 7 days. Group 3 was also treated with silymarin (100 mg/kg, PO) as a standard group, while groups 4 and 5 were administered with TSA oil at doses of 100 and 200 mg/kg PO, respectively. The nephrotoxicity was measured with various parameters such as kidney function markers, oxidative stress markers (glutathione (GSH) and malondialdehyde (MDA)), and messenger ribonucleic acid (mRNA) expression levels of inflammatory factors. The histological studies were also evaluated in the experimental protocol. The CdCl2-treated groups showed a significant increase in the levels of serum kidney function markers along with MDA levels in kidney homogenate. However, renal GSH level was found to be reduced significantly. It was found that CdCl2 significantly upregulated the nuclear factor levels of kappaB (NF-κB p65), inducible nitric oxide synthase (iNOS), and small mothers against decapentaplegic (Smad2) as compared to the normal control group. On the other hand, TSA oil significantly improved the increased levels of serum kidney function markers, non-enzymatic antioxidants, and lipid peroxidation. In addition, TSA oil significantly downregulated the increased expression of NF-κB p65, iNOS, and Smad2 in Cd-intoxicated rats. Moreover, the histological changes in the tissue samples of the kidney of Cd-treated groups were significantly ameliorated in the silymarin- and TSA-oil-treated groups. The present study reveals that TSA oil ameliorates Cd-induced renal injury, and it is also proposed that the observed nephroprotective effect could be due to the antioxidant potential of TSA oil and healing due to its anti-inflammatory action.  相似文献   

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