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121.
Mira Syahfriena Amir Rawa Nurul Amira Nurul Azman Suriani Mohamad Toshihiko Nogawa Habibah A. Wahab 《Molecules (Basel, Switzerland)》2022,27(9)
Macaranga tanarius (MT) and Syzygium jambos (SJ) are pharmacologically reported to have anti-oxidant, anti-inflammatory, and anti-diabetic effects, and can be neuroprotective agents. Our previous work revealed that MT and SJ exhibited 76.32% and 93.81% inhibition against acetylcholinesterase (AChE) at 50 μg/mL final concentration in their ethyl acetate and hexane fractions, respectively. This study was aimed to investigate the bioactive constituents of MT and SJ and their molecular mechanism toward AChE inhibition. Bioassay-guided isolation afforded prenylflavonoids 1–3 from MT and anacardic acid derivatives 4 and 5 from SJ that were confirmed by NMR and MS data. Compound 5 exerted the strongest anti-AChE potential (IC50: 0.54 μM), followed by 1, 4, 3, and 2 (IC50: 1.0, 2.4, 6.8, and 33 μM, respectively). In silico molecular docking revealed 5 formed stronger molecular interactions including three H-bonds than its derivative 4 based on the saturation of their alkyl chains. The addition of a five carbon-prenyl chain in 1 increased the number of binding interactions, justifying its greater activity than derivatives 2 and 3. This research reflects the first report of AChE inhibitors from these species, thereby adding pharmacological values to MT and SJ as potential remedies in neuroprotection. 相似文献
122.
Mai E. Hussein Osama G. Mohamed Ahlam M. El-Fishawy Hesham I. El-Askary Amira S. El-Senousy Ahmed A. El-Beih Eman S. Nossier Ahmed M. Naglah Abdulrahman A. Almehizia Ashootosh Tripathi Ahmed A. Hamed 《Molecules (Basel, Switzerland)》2022,27(3)
The rapid spread of bacterial infection caused by Staphylococcus aureus has become a problem to public health despite the presence of past trials devoted to controlling the infection. Thus, the current study aimed to explore the chemical composition of the extract of endophytic fungus Aspergillus fumigatus, isolated from Albizia lucidior leaves, and investigate the antimicrobial activity of isolated metabolites and their probable mode of actions. The chemical investigation of the fungal extract via UPLC/MS/MS led to the identification of at least forty-two metabolites, as well as the isolation and complete characterization of eight reported metabolites. The antibacterial activities of isolated metabolites were assessed against S. aureus using agar disc diffusion and microplate dilution methods. Compounds ergosterol, helvolic acid and monomethyl sulochrin-4-sulphate showed minimal inhibitory concentration (MIC) values of 15.63, 1.95 and 3.90 µg/mL, respectively, compared to ciprofloxacin. We also report the inhibitory activity of the fungal extract on DNA gyrase and topoisomerase IV, which led us to perform molecular docking using the three most active compounds isolated from the extract against both enzymes. These active compounds had the required structural features for S. aureus DNA gyrase and topoisomerase IV inhibition, evidenced via molecular docking. 相似文献
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124.
A mathematical model of a horseradish peroxidase biosensor was applied to simulate the amperometric response for the detection of hydrogen peroxide. The development of the mathematical model was based on the Michaelis–Menten equation and Fick’s Second Law. The theoretical study is based on the determination of physico-chemical and geometric parameters of a horseradish peroxidase biosensor as well as the kinetic parameters of reaction mechanism such as diffusion coefficients of hydrogen peroxide, the thickness of enzymatic layer, and the Michaelis–Menten kinetic constant. The theoretical analysis provides an accurate estimate of parameters affecting the biosensor performance such as the diffusion coefficient of hydrogen peroxide in the biomembrane that was estimated to be 56?×?10?12 m2/s. The thickness of diffusion layer was estimated to be 80–100?µm and the biomembrane 7.5?µm. The experimental and numerical values of kinetic parameters were 0.92 and 0.98?µM for the Michaelis–Menten constants and 0.010 and 0.012?µM/s for the catalytic activity rates. The model was validated for hydrogen peroxide detection and exhibited a good agreement with the experimental measurements. 相似文献
125.
Much effort has been focused on developing methods for detecting damaged nucleic acids. However, almost all of the proposed methods consist of multi-step procedures, are limited, require expensive instruments, or suffer from a high level of interferences. In this paper, we present a novel simple, inexpensive, mix-and-read assay that is generally applicable to nucleic acid damage and uses the enhanced luminescence due to energy transfer from nucleic acids to terbium(III) (Tb3+). Single-stranded oligonucleotides greatly enhance the Tb3+ emission, but duplex DNA does not. With the use of a DNA hairpin probe complementary to the oligonucleotide of interest, the Tb3+/hairpin probe is applied to detect ultraviolet (UV)-induced DNA damage. The hairpin probe hybridizes only with the undamaged DNA. However, the damaged DNA remains single-stranded and enhances the intrinsic fluorescence of Tb3+, producing a detectable signal directly proportional to the amount of DNA damage. This allows the Tb3+/hairpin probe to be used for sensitive quantification of UV-induced DNA damage. The Tb3+/hairpin probe showed superior selectivity to DNA damage compared to conventional molecular beacons probes (MBs) and its sensitivity is more than 2.5 times higher than MBs with a limit of detection of 4.36 ± 1.2 nM. In addition, this probe is easier to synthesize and more than eight times cheaper than MBs, which makes its use recommended for high-throughput, quantitative analysis of DNA damage. 相似文献
126.
Sadeek Atia Sadeek Sherif Mohamed Abd El‐Hamid Amira A. Mohamed Wael A. Zordok Hassan A. El‐Sayed 《应用有机金属化学》2019,33(5)
The mixed‐ligand Mn(II), Fe(III), Ni(II), Cu(II), Zn(II) and Zr(IV) complexes of meloxicam (H2mel) and 2,2′‐bipyridine (Bipy) were prepared and characterized. For all complexes, the analytical and spectroscopic results revealed that H2mel acts in a monobasic bidentate manner through the oxygen of the amide and nitrogen of the thiazole groups, whereas Bipy coordinates through the two nitrogen atoms with slightly distorted octahedral geometry. Thermodynamic parameters (E, ΔS*, ΔH* and ΔG*) were calculated using Coats–Redfern and Horowitz–Metzger methods. The geometries of H2mel and the complexes were carefully studied using density functional theory to predict the properties of materials performed using the hybrid density functional method B3LYP. All studied complexes are soft with respect to H2mel where η varies from 0.096 for Zn(II) complex to 0.067 for Fe(III) complex and σ varies from 10.42 to 14.93 eV, while η and σ for H2mel are 0.14 and 7.14 eV, respectively. The antibacterial activities of the ligands and metal complexes were investigated and the data show that the complexes are active against some bacterial species compared with H2mel. 相似文献
127.
128.
Amira Awadalla Mohamed R. Mahdi Mohamed H. Zahran Ahmed Abdelbaset-Ismail Mohamed El-Dosoky Amr Negm 《Molecules (Basel, Switzerland)》2022,27(7)
Cisplatin (CP) is a conventional chemotherapeutic agent with serious adverse effects. Its toxicity was linked to the stimulation of oxidative stress and inflammation. As a result, this study explored the protective effect of baicalein and alpha-tocopherol in nephrotoxicity induced by cisplatin. Until receiving an intraperitoneal injection of CP (3 mg/kg BW), rats were given baicalein orally 100 mg/kg for seven days or/and a single intraperitoneal injection of α-tocopherol 250 mg/kg. Renal function was tested to explore whether baicalein and α-tocopherol have any beneficial effects; blood urea nitrogen (BUN), serum creatinine, malondialdehyde (MDA) content, antioxidant activity biomarkers and histopathology of renal tissue, oxidative stress biomarkers, inflammatory response markers, and histopathological features of kidney architecture were measured. Cisplatin treatment resulted in extreme renal failure, as measured by high serum creatinine and BUN levels and severe renal changes. Cisplatin therapy resulted in increased lipid peroxidation and decreased glutathione and superoxide dismutase levels, reflecting oxidative stress. Upon treatment with α-tocopherol, baicalein, and combined therapy, there was augmentation in the antioxidant status as well as a reduction in IL-6, NF-κB, TNF, TLR2, and TLR4 and a significant increase in Keap-1 and NRF-2. The combined treatment was the most effective and the nearest to the normal status. These findings suggest that baicalein and α-tocopherol may be useful in preventing cisplatin-induced nephrotoxicity. 相似文献
129.
Synthesis of Some New Heterocycles Derived from Novel 2‐(1,3‐Dioxisoindolin‐2‐yl)Benzoyl Isothiocyanate 下载免费PDF全文
Novel 2‐(1,3‐Dioxisoindolin‐2‐yl)benzoyl isothiocyanate was prepared and underwent addition–cyclization reactions with some nucleophilic reagents. Simultaneous or subsequent cyclization of the obtained adducts gave a diverse range of differently sized heterocycles and thioureas. The structures of the synthesized compounds were confirmed by microanalytical and spectral data. 相似文献
130.
Adel A.‐H. Abdel‐Rahman Omar M. Ali Amira A.‐S. Abdel‐Megeed 《Journal of heterocyclic chemistry》2013,50(3):484-489
New tetrazole derivatives linked to isoindole‐1,3‐dione were prepared starting from the corresponding nitrile derivatives. The substituted hydrazides, their corresponding sugar hydrazones, and the derived acyclic C‐nucleoside analogs were also synthesized. The antimicrobial results indicated that most of the tested compounds exhibited moderate to high activity, whereas few compounds were found to exhibit little or no activity against the tested microorganisms. 相似文献