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排序方式: 共有165条查询结果,搜索用时 15 毫秒
1.
Two new divalent copper (C1) and zinc (C2) chelates having the formulae [M(PIMC)2] (where M = Cu(II), Zn(II) and PIMC = Ligand [(E)-3-(((3-hydroxypyridin-2-yl)imino)methyl)-4H-chromen-4-one] were obtained and characterized by several techniques. Structures and geometries of the synthesized complexes were judged based on the results of alternative analytical and spectral tools supporting the proposed formulae. IR spectral data confirmed the coordination of the ligands to the copper and zinc centers as monobasic tridentate in the enol form. Thermal analysis, UV-Vis spectra and magnetic moment confirmed the geometry around the copper center to be tetrahedral, square pyramidal and octahedral. Study of the binding ability of the synthesized compounds with Circulating tumor DNA (CT-DNA) bas been evaluated applying UV-Vis spectral titration and viscosity measurements. The copper and zinc oxides were achieved from the copper and zinc nano-particles structures Schiff base complexes as the raw material after calcination for 5 hr at 600°C. On the other hand, synthesized of C1 and C2 NPs were used as suitable precursors to the preparation of CuO and ZnO NPs. Finally, the synthesized of the two complexes exhibited enhanced activity against the tested bacterial (Staphylococcus aureus and Escherichia Coli) and fungal strains (Candida albicans and Aspergillus fumigatus) as compared to HPIMC. Among all these synthesized compounds, C1 exhibits good cleaving ability compared to other newly synthesized C2. 相似文献
2.
Saddam Saqib Wajid Zaman Fazal Ullah Imran Majeed Asma Ayaz Muhammad Farooq Hussain Munis 《应用有机金属化学》2019,33(11)
The ever‐increasing resistance of plant microbes towards fungicides and bactericides has been causing serious threat to plant production in recent years. For the development of an effective antifungal agent, we introduce a novel hydrothermal protocol for synthesis of chitosan iron oxide nanoparticles (CH‐Fe2O3 NPs) using acetate buffer of low pH 5.0 for intermolecular interaction of Fe2O3 NPs and CH. The composite structure and elemental elucidation were carried out by using X‐ray power diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X‐ray (EDX), Transmission Electron Microscopy (TEM), Fourier Transformed Infrared Spectroscopy (FTIR) and Ultraviolet Visible Absorption Spectroscopy (UV–vis spectroscopy). Additionally, antifungal activity was evaluated both In vitro and In vivo against Rhizopus oryzae which is causing fruit rot disease of strawberry. We compared different concentrations (0.25%, 0.50%, 075% and 1%) of CH‐Fe2O3 NPs and 50% synthetic fungicide (Matalyxal Mancozab) to figure out suitable concentration for application in the field. XRD analysis showed a high crystalline nature of the NPs with average size of 52 nanometer (nm). SEM images revealed spherical shape with size range of 50–70 nm, whereas, TEM also revealed spherical shape, size ranging from 0 nm to 80 nm. EDX and FTIR results revealed presence of CH on surface of Fe2O3 NPs. The band gap measurement showed peak 317–318 nm for bare Fe2O3 NPs and CH‐Fe2O3 NPs respectively. Antifungal activity in both In vitro and In vivo significantly increased with increase in concentration. The overall results revealed high synergetic antifungal potential of organometallic CH‐Fe2O3 NPs against Rhizopus oryzae and suggest the use of CH‐Fe2O3 NPs against other Phyto‐pathological diseases due to biodegradable nature. 相似文献
3.
A new electrochemical sensor based on Fe3O4@SiO2‐PANI‐Au nanocomposite was fabricated for modification of glassy carbon electrode (Fe3O4@SiO2‐PANI‐Au GCE). The Fe3O4@SiO2‐PANI‐Au nanocomposite was characterized by TEM, FESEM‐EDS‐Mapping, XRD, and TGA methods. The Fe3O4@SiO2‐PANI‐Au GC electrode exhibited an acceptable sensitivity, fast electrochemical response, and good selectivity for determination of quercetin. Under optimal conditions, the linear range for quercetin concentrations using this sensor was 1.0×10?8 to 1.5×10?5 mol L?1, and the limit of detection was 3.8×10?9 mol L?1. The results illustrated that the offered sensor could be a possible alternative for the measurement of quercetin in food samples and biological fluids. 相似文献
4.
A microextraction procedure based on a task‐specific ionic liquid for the separation and preconcentration of lead ions from red lipstick and pine leaves 下载免费PDF全文
Asma Saljooqi Tayebeh Shamspur Maryam Mohamadi Daryoush Afzali Ali Mostafavi 《Journal of separation science》2015,38(10):1777-1783
First, the extraction and preconcentration of ultratrace amounts of lead(II) ions was performed using microliter volumes of a task‐specific ionic liquid. The remarkable properties of ionic liquids were added to the advantages of microextraction procedure. The ionic liquid used was trioctylmethylammonium thiosalicylate, which formed a lead thiolate complex due to the chelating effect of the ortho‐positioned carboxylate relative to thiol functionality. So, trioctylmethylammonium thiosalicylate played the roles of both chelating agent and extraction solvent simultaneously. Hence, there is no need to use a ligand. The main parameters affecting the efficiency of the method were investigated and optimized. Under optimized conditions, this approach showed a linear range of 2.0–24.0 ng/mL with a detection limit of 0.0010 ng/mL. The proposed method was applied to the extraction and preconcentration of lead from red lipstick and pine leaves samples prior to electrothermal atomic absorption spectroscopic determination. 相似文献
5.
Tasneem Gul Kazi Suraya Samejo Hassan Imran Afridi Asma Akhtar Jameel Ahmed Baig 《应用有机金属化学》2020,34(1):e5263
In the present study the cadmium (Cd) was determined in serum samples of psoriatic patients. The severity of psoriasis was evaluated according to criteria based on standard clinical diagnosis using Psoriasis Area Severity Index (PASI) score. In present study, an innovative tunable green solvent system based microextraction (TSS-ME) was applied for the enrichment of Cd in acid digested serum samples prior to determination with flame atomic absorption spectrometry. The hydrophobic complex of Cd-ammonium pyrrolidine thiocarbamate was extracted in a tunable solvent system which was prepared from a polybasic amine (N, N, N′, N′-tetramethyl-1, 4-diaminobutane), decanol and water system. The tunable green solvent system (TSS) which has zero ionic strength was converted to homogeneous monophasic polar hydrophilic phase via exposure to CO2 at different pressure and time duration. Then hydrophobic enriched Cd- ammonium pyrrolidine thiocarbamate was back extracted, using HNO3 (0.1 to 0.5 mol L−1) then the second round of TSS-ME was applied. The acidic aqueous phase enrich with analyte was separated from tunable solvent. The separated TSS was easily reused for up to 10 time for preconcentration purposes without loss of its enrichment character. The smoker and nonsmoker psoriatic patients at PASI >10, have two to three folds higher Cd levels in serum samples than healthy persons. 相似文献
6.
Dissolution of Cellulose and Lignin with Biobased Ionic Liquids 总被引:1,自引:0,他引:1
Mbakidi Jean-Pierre Kerkache Asma Lazar Florica Bouquillon Sandrine 《Journal of solution chemistry》2022,51(3):345-356
Journal of Solution Chemistry - Choline-based ionic liquids, involving various alkyl chains lengths and carboxylates derived from biobased acids, have been synthetized with high yields through a... 相似文献
7.
Asma Kaoukabi Larbi Belachemi Mohammed Lahcini Marie‐Claude Viaud Massuard Ccile Croix 《Journal of heterocyclic chemistry》2019,56(4):1260-1274
In an attempt to improve anticancer activity, a series of retinoids–chromene hybrids was described. The novel heterocyclic chromene–retinoids hybrid including oxygen as a heteroatom in a six‐membered cyclic ring (2H‐chromene or 2H‐1‐benzopyran) was designed and synthesized by introducing different groups such as an aromatic or styrylphenyl ring in 6‐position of 2H‐chromene. These novel compounds were synthesized by using the efficient cascades one‐pot process involving Wittig–Horner–Emmons reaction and Suzuki–Miyaura cross‐coupling pallado‐catalyzed reactions with 60% to 90% overall yields. These new compounds were tested against glioblastoma multiforme brain cancer, medulloblastoma, neuroblastoma cell lines, and breast cancer MCF‐7 cell lines. Two of them exhibited an appreciable anti‐tumor activity in the low micromolar range, which opens new perspectives for therapeutic application on humans. 相似文献
8.
Acylation of cholest-5-ene and cholest-5-ene 3-one with anhydrides in the presence of zinc chloride and characterization of products thus obtained on the basis of elemental analysis, spectral data, and chemical transformations are reported. 相似文献
9.
Ruohu Zhang Zhuyuan Wang Chunyuan Song Jing Yang Asma Sadaf Yiping Cui 《Journal of fluorescence》2013,23(1):71-77
A novel gap-plasmon-tunable Ag bilayer nanoparticle film for immunoassays is demonstrated. Different from a traditional Ag monolayer nanoparticle film, a desired number of polyelectrolyte (PEL) layers are deposited on the nanoparticles before the self-assembly of a second Ag nanoparticle layer. Interestingly, by controlling the number of the PEL interlayers, the gap plasmon between the two Ag nanoparticle layers can be tuned across the visible spectral range. The ability of the presented Ag bilayer nanoparticle films in fluorescence enhancement has been examined experimentally. A maximal enhancement of around 15.4 fold was achieved when 7 layers of polyelectrolyte were used. When this optimal Ag bilayer nanoparticle film was applied to fluorescence immunoassay, a performance with approximately 3.3-fold enhancement was obtained compared with that performed on a traditional glass substrate. The experimental results suggest that the presented gap-plasmon tunable Ag bilayer nanoparticle films have great potential in fluorescence-based immunoassays. The method of the bilayer-film construction presented here also provides new insights into the rational design of the plasmonic substrates. 相似文献
10.
Ines ELBini-Dhouib Raoudha Doghri Amenallah Ellefi Imen Degrach Najet Srairi-Abid Asma Gati 《Molecules (Basel, Switzerland)》2021,26(10)
Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases leading to dementia. Despite research efforts, currently there are no effective pharmacotherapeutic options for the prevention and treatment of AD. Recently, numerous studies highlighted the beneficial effects of curcumin (CUR), a natural polyphenol, in the neuroprotection. Especially, its dual antioxidant and anti-inflammatory properties attracted the interest of researchers. In fact, besides its antioxidant and anti-inflammatory properties, this biomolecule is not degraded in the intestinal tract. Additionally, CUR is able to cross the blood–brain barrier and could therefore to be used to treat neurodegenerative pathologies associated with oxidative stress, inflammation and apoptosis. The present study aimed to assess the ability of CUR to induce neuronal protective and/or recovery effects on a rat model of neurotoxicity induced by aluminum chloride (AlCl3), which mimics the sporadic form of Alzheimer’s disease. Our results showed that treatment with CUR enhances pro-oxidant levels, antioxidant enzymes activities and anti-inflammatory cytokine production and decreases apoptotic cells in AlCl3-exposed hippocampus rats. Additionally, histopathological analysis of hippocampus revealed the potential of CUR in decreasing the hallmarks in the AlCl3-induced AD. We also showed that CUR post-treatment significantly improved the behavioral, oxidative stress and inflammation in AlCl3-exposed rats. Taken together, our data presented CUR as a nutraceutical potential through its protective effects that are more interesting than recovery ones in sporadic model of AD. 相似文献