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121.
Fatma M. Abdel Bar Manal A. Alossaimi Engy Elekhnawy May Abdullah Abulrahman Alzeer Amal Abo Kamer Ehssan Moglad Mai H. ElNaggar 《Molecules (Basel, Switzerland)》2022,27(22)
HPLC-UV was used to compare the major constituents of two Pelargonium × hortorum cultivars and Pelargonium sidoides root extract. It revealed the presence of catechin and gallic acid in high concentrations and the absence of umckalin in P. × hortorum root extracts. The antibacterial activity of these extracts was screened against 19 Pseudomonas aeruginosa clinical isolates. P. × hortorum root extracts showed the lowest MIC values (512–1024 µg/mL). This activity was concluded to be attributable to the high concentrations of catechin and gallic acid. The anti-biofilm activity of catechin, gallic acid, and their combination was examined by a crystal violet assay. The combination reduced the percentage of strong and moderate biofilm-forming isolates from 52.63% to 5.26%. The impact on lasI and lasR genes expression using qRT-PCR and simultaneous docking against LasR protein was explored. The combination downregulated lasI and lasR gene expression in eight and six P. aeruginosa isolates, respectively, and showed the greatest docking score. Additionally, the in vivo protection capability of this combination in infected mice showed enhancement in the survival rate. Our study revealed the potential biofilm and quorum-sensing-inhibitory activity of the catechin and gallic acid combination as a novel alternative to inhibit bacterial pathogenicity. 相似文献
122.
John Ojur Dennis Mohammed Khalil Mohammed Ali Khalid Hassan Ibnaouf Osama Aldaghri Naglaa F. M. Abdel All Abdullahi Abbas Adam Fahad Usman Yarima Mudassir Hassan Bashir Abubakar Abdulkadir 《Molecules (Basel, Switzerland)》2022,27(17)
In this study, a solution casting method was used to prepare solid polymer electrolytes (SPEs) based on a polymer blend comprising polyvinyl alcohol (PVA), cellulose acetate (CA), and potassium carbonate (K2CO3) as a conducting salt, and zinc oxide nanoparticles (ZnO-NPs) as a nanofiller. The prepared electrolytes were physicochemically and electrochemically characterized, and their semi-crystalline nature was established using XRD and FESEM. The addition of ZnO to the polymer–salt combination resulted in a substantial increase in ionic conductivity, which was investigated using impedance analysis. The size of the semicircles in the Cole–Cole plots shrank as the amount of nanofiller increased, showing a decrease in bulk resistance that might be ascribed to an increase in ions due to the strong action of the ZnO-NPs. The sample with 10 wt % ZnO-NPs was found to produce the highest ionic conductivity, potential window, and lowest activation energy (Ea) of 3.70 × 10–3 Scm–1, 3.24 V, and 6.08 × 10–4 eV, respectively. The temperature–frequency dependence of conductivity was found to approximately follow the Arrhenius model, which established that the electrolytes in this study are thermally activated. Hence, it can be concluded that, based on the improved conductivity observed, SPEs based on a PVA-CA-K2CO3/ZnO-NPs composite could be applicable in all-solid-state energy storage devices. 相似文献
123.
Abdel Nasser B. Singab Nada M. Mostafa Iten M. Fawzy Deepika Bhatia Pooja Tanaji Suryawanshi Atul Kabra 《Molecules (Basel, Switzerland)》2022,27(19)
Maintaining healthy skin is important for a healthy body. At present, skin diseases are numerous, representing a major health problem affecting all ages from neonates to the elderly worldwide. Many people may develop diseases that affect the skin, including cancer, herpes, and cellulitis. Long-term conventional treatment creates complicated disorders in vital organs of the body. It also imposes socioeconomic burdens on patients. Natural treatment is cheap and claimed to be safe. The use of plants is as old as mankind. Many medicinal plants and their parts are frequently used to treat these diseases, and they are also suitable raw materials for the production of new synthetic agents. A review of some plant families, viz., Fabaceae, Asteraceae, Lamiaceae, etc., used in the treatment of skin diseases is provided with their most common compounds and in silico studies that summarize the recent data that have been collected in this area. 相似文献
124.
Simple, rapid, accurate, and sensitive spectrophotometric methods are described for the determination of dicyclomine hydrochloride. The methods are based on the reaction of this drug as an n-electron donor with 2,3-dichloro-5,6-dicyano-p-benzoqunione (DDQ), p-chloranilic acid (p-CA), and chloranil (CL) as pi-acceptors to give highly colored complex species. The colored products are measured spectrophotometrically at 456, 530, and 650 nm for DDQ, p-CA, and CL, respectively. Optimization of the different experimental conditions were studied. Beer's law was obeyed in concentration ranges of 20-100, 50-250, and 80-600 microg/mL for DDQ, pCA, and CL, respectively. Colored complexes are produced in organic solvents and are stable for at least 1 h. The methods were applied to Spasmorest antispasmotic tablets and ampoules with good accuracy and precision. 相似文献
125.
126.
Abdel‐Sattar S. Hamad Elgazwy 《应用有机金属化学》2007,21(12):1041-1053
Reactions of 2,5‐dibromothiophene, 1 , with [Pd2(dba)3]?dba [Pd(dba)2; dba = dibenzylideneacetone] in the presence of N‐donor ligands such as 2,2′‐bipyridine (bpy) and 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine (dtbbpy) give arylpalladium complexes of cis‐[2‐(5‐BrC4H2S)PdBrL2], 2a, b [L2 = bpy ( 2a ), L2 = dtbbpy ( 2b )], and cis‐cis‐L2PdBr[2,5‐(C4H2S‐)PdBr(L2)], 3a, b [L2 = bpy ( 3a ), L2 = dtbbpy ( 3b )]. Treatment of cis complexes 2a, b and 3a, b with CO causes the insertion of CO into the Pd? C bond to give the aroyl derivatives of palladium complexes of cis‐[2‐(5‐BrC4H2S)COPdBrL2], 4a, b [L2 = bpy ( 4a ), L2 = dtbbpy ( 4b )], and cis‐cis‐[(L2)(CO)BrPdC4H2S‐PdBr(CO)(L2)], 5a, b [L2 = bpy ( 5a ) and L2 = dtbbpy ( 5b )], respectively. Treating complexes 2a, b with 1 mole equivalent of isocyanide XyNC (Xy = 2,6‐dimethylphenyl) gave iminoacyl complexes cis‐[2‐(5‐BrC4H2S)C?NXyPdBrL2], 6a, b [L2 = bpy ( 6a ), L2 = dtbbpy ( 6b )], and a 3‐fold excess of isocyanide XyNC (Xy = 2,6‐dimethylphenyl) gave triiminoacyl complexes [2‐(5‐BrC4H2S)(C?NXy)3 PdBr], 7 . Cyclization reactions of 6a, b with 3 mole equivalents of isocyanide XyNC (Xy = 2,6‐dimethylphenyl) or cyclization reaction of 7 with 1 mole equivalent of isocyanide XyNC (Xy = 2,6‐dimethylphenyl) both gave tetraiminoacyl complexes of [2‐(5‐BrC4H2S)(C?NXy)4PdBr], 8 , which was also obtained by the reaction of 1 or 2a, b with a 4‐fold excess of isocyanide XyNC with or without add Pd(dba)2. Similarly, complexes 3a and b were also reacted with 2 mole equivalents of isocyanide XyNC (Xy = 2,6‐dimethylphenyl) to give iminoacyl complexes cis‐cis‐[(L2)(CNXy)BrPdC4H2S‐PdBr(CNXy)(L2)], 10a, b [L2 = bpy ( 10a ), L2 = dtbbpy ( 10b )] and an 8‐fold excess of isocyanide XyNC (Xy = 2,6‐dimethylphenyl) afforded tetraiminoacyl complexes of [2,5‐(C4H2S)(C?NXy)8Pd2Br2], 11 . Complexes 2a, b and 3a, b reacted with TlOTf [(TfO = CF3SO3)] in CH2Cl2 to give 9a, b and 12a, b , respectively, in a moderate yield. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
127.
The prototropic rearrangement of 3-phenyl-1-propenes to the corresponding 1-phenyl-1-propenes was investigated in basic media utilizing 0.1M sodium ethoxide in absolute ethanol at 81°C. It was found that the effect of substituents on the rate of such isomerizations follows the order: p-NO2 > o-Cl > m-Cl ≥ m-F > p-Br > o-CH3 > m-CH3 > m-CH(CH3)2 > p-CH(CH3)2 ≥ p-C(CH3)3 > o-OCH3. This is consistent with first-order kinetics and “BS” mechanism. Quantitative treatment in terms of Hammett's equation showed a straight line, with a slope (p value) of +2.25. An increase in the strength of the base was also found to cause an increase in the rate of isomerization. 相似文献
128.
Two simple, precise, inexpensive and sensitive voltammetric methods for the determination of lomefloxacin (LFX), sparfloxacin hydrochloride (SFX), gatifloxacin (GFX), and moxifloxacin (MFX) were developed. The present methods were first used to explore the adsorption behavior of the four investigated antibacterial agents at a hanging mercury dropping electrode (HMDE), by a direct method and secondly by a modification via their complexation with PdCl(2). For the direct method, drugs were accumulated on HMDE, and a well-defined reduction peak was obtained in Britton-Robinson buffer of pH 7 for LFX and SFX, and pH 6 for GFX and MFX. The adsorptive stripping response was evaluated as a function of some variables such as the scan rate, pH, accumulation time and potential. For the modified method, the adsorptive behavior of Pd(II)-4-quinolone complexes at the HMDE developed a strippining voltammetry peak at a more negative potential than that of the free Pd(II) ions (-1.05 V). The limits of detection (LOD) were 2 x 10(-8) M, while the limits of quantification (LOQ) were 6 x 10(-8) M for the investigated drugs. The methods were applied to the determination of LFX, SFX, GFX, and MFX in biological samples and pharmaceutical preparations, and also compared with the official reference methods. Complete validation of the proposed methods was also done. 相似文献
129.
Hafez S. Abdel Wahab J. Bérczi L. Bognár G. Keömley 《Journal of Radioanalytical and Nuclear Chemistry》1977,36(2):479-490
Twelve zircon samples representing different genetic types from Australia, China, Egypt, Hungary, Korea and Nigeria were examined
using the neutron activation techniques. The study of the trace elements encountered in zircons, especially Zr/Hf ratios,
shed the light on the type of zircon minerals as well as the mother rock from which zircons wrre separated. Furthermore, the
effect of the secondary processes on zircons and their host rocks were also studied. 相似文献
130.
Zusammenfassung Es wird ein zweites graphisches Verfahren dargestellt, welches gestattet, die Viskosität zäher Flüssigkeiten zu ermitteln. 相似文献