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101.
Wedad A. Al-Onazi Amal M. Al-Mohaimeed Zainab M. Almarhoon Eida S. Al-Farraj Asma A. Alothman 《中国化学会会志》2020,67(1):125-134
A potentiometric method was used to determine the stability constants for the various complexes of copper(II) with carbamoylcholine chloride (C) drug as a ligand in the presence of some biorelevant amino acid constituents like glycine (Gly), alanine (Ala), valine (Val), proline (Pro), β-phenylalanine (Phe), S-methylcysteine (Met), threonine (Thr), ornithine (Orn), lysine (Lys), histidine (Hisd), histamine (Hist), and imidazole (Imz) as ligands (L). Stability constants of complexes were determined at 25°C and I = 0.10 mol/L NaNO3. The relative stability of each ternary complex was compared with that of the corresponding binary complexes in terms of Δlog K and % R.S. values. Cu(II) complexes of drug C were synthesized in 1:1 and 1:1:1 M ratios of copper to drug [Cu(C)(NO3)2] (1) and copper to drug to glycine[Cu(C)(Gly)(NO3)].NO3 (2), respectively. Glycine ternary complex with drug and copper [Cu(C)(Gly)(NO3)].NO3 was considered as representative amino acid. The complexes 1 and 2 were isolated and characterized using various physicochemical and spectral techniques. Both complexes 1 and 2 were found to have magnetic moments corresponding to one unpaired electron. The possible square planar and square-pyramidal geometries of the copper (II) complexes were assigned on the basis of electron paramagnetic resonance (EPR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), ultraviolet–visible (UV–Vis) and infrared (IR) spectral studies, and the discrete Fourier transform method from DMOL3 calculations. Antioxidant activities of all the synthesized compounds were also investigated. 相似文献
102.
In the search of effective bioactive compounds, Co(II) ( C1 ) and Cd(II) ( C2 ) complexes of the type [M(FMAPIMP)(H2O)Cl].nH2O (where M = Co(II); n = 2, Cd(II); n = 3, and FMAPIMP = ligand[2-((E)-((2-(((E)-furan-2-ylmethylene)amino)phenyl)imino)methyl)phenol]) were synthesized and characterized using elemental analysis, UV–Vis., cyclic voltammetry, Fourier-transform infrared (FT-IR), nuclear magnetic resonance, and mass spectral studies. The thermal stability of nano-sized Co(II) and Cd(II) complexes was studied using thermogravimetric analysis (TGA). Cobalt and cadmium oxides were synthesized using cobalt and cadmium nanoparticle (NP) structure Schiff base complexes as the raw material after calcination for 5 h at 600 °C. According to the results, Co(II) and Cd(II) complexes with mole ratio 1:1 of metal: H-FMAPIMP which octahedral are the most probable geometry for it. On the contrary, synthesized C1 and C2 NPs were used as suitable precursors for the preparation of CoO and CdO NPs. The obtained NPs were characterized using FT-IR, UV–Vis., TGA, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy techniques. PXRD analysis revealed that the obtained oxides were crystalline and corresponded to CoO and CdO phases. Crystal size, shape, and morphology were determined using SEM and TEM. H-FMAPIMP and its two complexes ( C1 and C2 ) were tested against human ovarian cancer cell line (PA-1). The synthesized Co(II) and Cd(II) complexes exhibited enhanced activity against the tested bacterial (Staphylococcus aureus and Escherichia Coli) and fungal strains (Candida albicans and Aspergillus fumigatus) as compared to H-FMAPIMP. The results of the DNA-cleavage activity indicated that the ligand and its two complexes can cleave calf thymus-DNA at different degrees. Further, antituberculosis activity was performed using microplate alamarBlue assay. Among all these synthesized compounds, C1 exhibited good cleaving ability compared to the newly synthesized C2 . Finally, the geometry of H-FMAPIMP and its Co(II) and Cd(II) complexes was optimized using molecular modeling. 相似文献
103.
Amir Sohail Asma Al Menhali Soleiman Hisaindee Iltaf Shah 《Molecules (Basel, Switzerland)》2021,26(17)
Introduction: The most common forms of vitamin D in human and mouse serum are vitamin D3 and vitamin D2 and their metabolites. The aim of this study is to determine whether diet and sunlight directly affect the circulating concentrations of vitamin D metabolites in a mouse model. We investigated the serum concentrations of eight vitamin D metabolites—vitamin D (vitamin D3 + vitamin D2), 25OHD (25OHD3 + 25OHD2), 1α25(OH)2D (1α25(OH)2D2, and 1α25(OH)2D3)—including their epimer, 3-epi-25OHD (3-epi-25OHD3 and 3-epi-25OHD2), and a bile acid precursor 7alpha-hydroxy-4-cholesten-3-one (7αC4), which is known to cause interference in liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Method: The LC-MS/MS method was validated according to FDA-US guidelines. The validated method was used for the analysis of mouse serum samples. Forty blood samples from mice were collected and divided into three groups. The first group, the DDD mice, were fed a vitamin D-deficient diet (25 IU VD3/kg of diet) and kept in the dark; the second group, the SDD mice, were maintained on a standard-vitamin D diet (1000 IU VD3) and kept in the dark; and the third group, SDL, were fed a standard-vitamin D diet (1000 IU VD3) but kept on a normal light/dark cycle. LC-MS/MS was used for the efficient separation and quantitation of all the analytes. Results: The validated method showed good linearity and specificity. The intraday and interday precision were both <16%, and the accuracy across the assay range was within 100 ± 15%. The recoveries ranged between 75 and 95%. The stability results showed that vitamin D metabolites are not very stable when exposed to continuous freeze–thaw cycles; the variations in concentrations of vitamin D metabolites ranged between 15 and 60%. The overlapping peaks of vitamin D, its epimers, and its isobar (7αC4) were resolved using chromatographic separation. There were significant differences in the concentrations of all metabolites of vitamin D between the DDD and SDL mice. Between the groups SDD (control) and SDL, a significant difference in the concentrations of 3-epi-25OHD was noted, where C3 epimer was about 30% higher in SDL group while no significant differences were noted in the concentrations of vitamin D, 25OHD, 1α25(OH)2D, and 7αC4 between SDD and SDL group. Conclusions: A validated method, combined with a simple extraction technique, for the sensitive LC-MS/MS determination of vitamin D metabolites is described here. The method can eliminate the interferences in LC-MS/MS analysis caused by the overlapping epimer and isobar due to them having the same molecular weights as 25OHD. The validated method was applied to mouse serum samples. It was concluded that a standard-vitamin D diet causes an increase in the proportion of all the vitamin D metabolites and C3 epimers and isobar, while UV light has no pronounced effect on the concentrations of the majority of the vitamin D metabolites except 3-epi-25OHD. Further studies are required to confirm this observation in humans and to investigate the biochemical pathways related to vitamin D’s metabolites and their epimers. 相似文献
104.
Investigation of ageing effects on the electrical properties of polyaniline/silver nanocomposites
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Polyaniline(PANI)/Ag nanocomposites, synthesized by incorporation of separately prepared silver nanoparticles in 1-methyl-2-pyrrolidinone(NMP) solution of PANI, have been aged at the accelerated temperature of 120 oC to simulate a storage period of 2 years at 25 oC. The accelerated ageing of these materials is done by using the activation energy calculated from data collected using heat flow calorimetry (HFC). The impedance spectroscopic studies of NMP plasticized aged nanocomposite films suggest a microphase separation into reduced and oxidized repeat units. There is crosslinking of the PANI films during ageing thereby obstructing the charge transfer between PANI chains and silver nanoparticles. As a result, the resistivity is increased. 相似文献
105.
Xinkun Wang Asma Zaidi Ranu Pal Alexander S Garrett Rogelio Braceras Xue-wen Chen Mary L Michaelis Elias K Michaelis 《BMC neuroscience》2009,10(1):12-20
Background
Oxidative stress (OS) is an important factor in brain aging and neurodegenerative diseases. Certain neurons in different brain regions exhibit selective vulnerability to OS. Currently little is known about the underlying mechanisms of this selective neuronal vulnerability. The purpose of this study was to identify endogenous factors that predispose vulnerable neurons to OS by employing genomic and biochemical approaches. 相似文献106.
Alkyl enol ethers (AEE) are versatile synthetic intermediates with a unique reactivity pattern. This review article summarizes the synthesis of AEE as well as its reactivity and how enol ether undergoes intermolecular reactions for various bond formation, leading to the construction of several useful organic molecules. The synthetic applications of alkyl enol ethers towards intermolecular bond-forming reactions include metal-catalyzed reactions, cycloaddition and heterocycle formation as well as rwactions in the field of natural products synthesis. The achievement of these impressive transformations prove the countless synthetic potential of AEE. The main objective of this review is to bring attentiveness among synthetic chemists to show how AEE extensively can be used to react with both electrophiles as well as nucleophiles, thereby behaving as an ambiphilic reactant. We trust that the unique reactivity pattern of alkyl enol ethers and the fundamental mechanistic idea can attract chemists in AEE chemistry. Exclusively, intermolecular reactions of AEE with other functionalized moieties have not been reviewed to the best of our knowledge. 相似文献
107.
Nasser?IranpoorEmail author Habib?FirouzabadiEmail author Asma?Riazi 《Journal of the Iranian Chemical Society》2015,12(1):155-165
In this study, synthesis and application of diphenylphosphorylated PEG200 (DPPPEG200) are described. Herein, we report a very simple procedure for the preparation of DPPPEG200 as a stable solid through the reaction of PEG200 with ClPPh2. This compound was used as a very suitable ligand for the in situ generation of nano-Pd(0) particles through its reaction with PdCl2 as a pre-catalyst. Isolation of this catalyst is very simple through addition of diethyl ether to the reaction mixture and centrifugations. Full characterization of the nano-Pd(0)/DPPPEG200 was performed by XRD spectra, UV–Vis spectra, and also by TEM image. This nano-complex was used as an efficient catalyst for copper-free Sonogashira and homocoupling reactions of aryl halides. The sonogashira reaction of aryl halides was conducted at 80 °C in PEG. However, the homocoupling reaction was performed at 100 °C for aryl iodides and activated aryl bromides and at 130 °C for deactivated aryl bromides and aryl chlorides in PEG. The catalyst was recovered and recycled for four consecutive runs. 相似文献
108.
Hasnain Mehmood Zahoor Ahmad Humaira M. Siddiqi Asma Iqbal Shahid Hameed 《Molecular Crystals and Liquid Crystals》2018,664(1):14-23
A series of ethyl 4-((4-alkoxyphenyl)diazenyl)benzoate is synthesized and the liquid crystalline behavior studied. Synthesized compounds are characterized by FTIR, 1H-NMR, Mass and single crystal XRD. Differential scanning calorimetry was carried out to study the phase transitions and enthalpy changes. Polarizing optical microscopy revealed the mesogenic properties. These techniques revealed that three compounds (2a, 2b, 2f) exhibit liquid crystalline properties in the range of 80–104°C. POM exhibiting focal conical fan like texture which revealed the presence of smectic phases suggestive of their use in LCD and temperature sensing devices, besides 2c can be used as green emitter in OLEDs. 相似文献
109.
Nisar Ahmad Palwasha Khan Abdullah Khan Maliha Usman Mohammad Ali Hina Fazal Durrishahwar Muhammad Nazir Uddin Christophe Hano Bilal Haider Abbasi 《Molecules (Basel, Switzerland)》2022,27(1)
Stevia rebaudiana is an important medicinal plant that belongs to the Asteraceae family. The leaves of Stevia rebaudiana are a rich source of many health-promoting agents such as polyphenols, flavonoids, and steviol glycoside, which play a key role in controlling obesity and diabetes. New strategies such as the elicitation of culture media are needed to enhance the productivity of active components. Herein, the Cuscuta reflexa extracts were exploited as elicitors to enhance the productivity of active components. Cuscuta reflexa is one of the parasitic plants that has the ability to elongate very fast and cover the host plant. Consequently, it may be possible that the addition of Cuscuta reflexa extracts to adventitious root cultures (ADR) of Stevia rebaudiana may elongate the root more than control cultures to produce higher quantities of the desired secondary metabolites. Therefore, the main objective of the current study was to investigate the effect of Cuscuta reflexa extract as a biotic elicitor on the biomass accumulation and production of antioxidant secondary metabolite in submerged adventitious root cultures of Stevia rebaudiana. Ten different concentrations of Cuscuta reflexa were added to liquid media containing 0.5 mg/L naphthalene acetic acid (NAA). The growth kinetics of adventitious roots was investigated for a period of 49 days with an interval of 7 days. The maximum biomass accumulation (7.83 g/3 flasks) was observed on medium containing 10 mg/L extract of Cuscuta reflexa on day 49. As the concentration of extract increases in the culture media, the biomass gradually decreases after 49 days of inoculation. In this study, the higher total phenolics content (0.31 mg GAE/g-DW), total flavonoids content (0.22 mg QE/g-DW), and antioxidant activity (85.54%) were observed in 100 mg/L treated cultures. The higher concentration (100 mg/L) of Cuscuta reflexa extract considerably increased the total phenolics content (TPC), total phenolics production (TPP), total flavonoids content (TFC), total flavonoids production (TFP), total polyphenolics content (TPPC), and total polyphenolics production (TPPP). It was concluded that the extract of Cuscuta reflexa moderately improved biomass accumulation but enhanced the synthesis of phenolics, flavonoids, and antioxidant activities. Here, biomass’s independent production of secondary metabolites was observed with the addition of extract. The present study will be helpful to scale up adventitious roots culture into a bioreactor for the production of secondary metabolites rather than biomass accumulation in medicinally important Stevia rebaudiana. 相似文献
110.
Nasser A. Hassan Asma K. Alshamari Allam A. Hassan Mohamed G. Elharrif Abdullah M. Alhajri Mohammed Sattam Reham R. Khattab 《Molecules (Basel, Switzerland)》2022,27(15)
Alzheimer’s disease (AD) is a chronic dysfunction of neurons in the brain leading to dementia. It is characterized by gradual mental failure, abnormal cognitive functioning, personality changes, diminished verbal fluency, and speech impairment. It is caused by neuronal injury in the cerebral cortex and hippocampal area of the brain. The number of individuals with AD is growing at a quick rate. The pathology behind AD is the progress of intraneuronal fibrillary tangles, accumulation of amyloid plaque, loss of cholinergic neurons, and decrease in choline acetyltransferase. Unfortunately, AD cannot be cured, but its progression can be delayed. Various FDA-approved inhibitors of cholinesterase enzyme such as rivastigmine, galantamine, donepezil, and NDMA receptor inhibitors (memantine), are available to manage the symptoms of AD. An exhaustive literature survey was carried out using SciFinder’s reports from Alzheimer’s Association, PubMed, and Clinical Trials.org. The literature was explored thoroughly to obtain information on the various available strategies to prevent AD. In the context of the present scenario, several strategies are being tried including the clinical trials for the treatment of AD. We have discussed pathophysiology, various targets, FDA-approved drugs, and various drugs in clinical trials against AD. The goal of this study is to shed light on current developments and treatment options, utilizing phytopharmaceuticals, nanomedicines, nutraceuticals, and gene therapy. 相似文献