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141.
Ullah Hayat Ullah Hafeez Taha M. Khan F. Rahim F. Uddin I. Sarfraz M. Shah S. A. Ali Aziz A. Mubeen S. 《Russian Journal of Organic Chemistry》2021,57(6):968-975
Russian Journal of Organic Chemistry - New benzimidazole derivatives were synthesized by reacting substituted phenacyl bromides with 1H-benzimidazole-2-thiols. The synthesized compounds were... 相似文献
142.
Shakeel Ahmad Khan Shafi Ullah Khan Fozia Najeeb Ullah Mohibullah Shah Riaz Ullah Ijaz Ahmad Amal Alotaibi 《Molecules (Basel, Switzerland)》2021,26(7)
Admittedly, the disastrous emergence of drug resistance in prokaryotic and eukaryotic human pathogens has created an urgent need to develop novel chemotherapeutic agents. Onosma chitralicum is a source of traditional medicine with cooling, laxative, and anthelmintic effects. The objective of the current research was to analyze the biological potential of Onosma chitralicum, and to isolate and characterize the chemical constituents of the plant. The crude extracts of the plant prepared with different solvents, such as aqueous, hexane, chloroform, ethyl acetate, and butanol, were subjected to antimicrobial activities. Results corroborate that crude (methanol), EtoAc, and n-C6H14 fractions were more active against bacterial strains. Among these fractions, the EtoAc fraction was found more potent. The EtoAc fraction was the most active against the selected microbes, which was subjected to successive column chromatography, and the resultant compounds 1 to 7 were isolated. Different techniques, such as UV, IR, and NMR, were used to characterize the structures of the isolated compounds 1–7. All the isolated pure compounds (1–7) were tested for their antimicrobial potential. Compounds 1 (4′,8-dimethoxy-7-hydroxyisoflavone), 6 (5,3′,3-trihydroxy-7,4′-dimethoxyflavanone), and 7 (5′,7,8-trihydroxy-6,3′,4′-trimethoxyflavanone) were found to be more active against Staphylococcus aureus and Salmonella Typhi. Compound 1 inhibited S. typhi and S. aureus to 10 ± 0.21 mm and 10 ± 0.45 mm, whereas compound 6 showed inhibition to 10 ± 0.77 mm and 9 ± 0.20 mm, respectively. Compound 7 inhibited S. aureus to 6 ± 0.36 mm. Compounds 6 and 7 showed significant antibacterial potential, and the structure–activity relationship also justifies their binding to the bacterial enzymes, i.e., beta-hydroxyacyl dehydratase (HadAB complex) and tyrosyl-tRNA synthetase. Both bacterial enzymes are potential drug targets. Further, the isolated compounds were found to be active against the tested fungal strains. Whereas docking identified compound 7, the best binder to the lanosterol 14α-demethylase (an essential fungal cell membrane synthesizing enzyme), reported as an antifungal fluconazole binding enzyme. Based on our isolation-linked preliminary structure-activity relationship (SAR) data, we conclude that O. chitralicum can be a good source of natural compounds for drug development against some potential enzyme targets. 相似文献
143.
Hira Aslam Shazia Shukrullah Muhammad Yasin Naz Hareem Fatima Sami Ullah Abdullah G. Al-Sehemi 《Particle & Particle Systems Characterization》2021,38(12):2100179
Magnetically guided drug transportation is a technique in which magnetic pharmaceutical transporters in organisms are controlled by applied magnetic forces to deliver drugs to the desired location. Different magnetic drug delivery systems (MDDSs) are developed to treat a variety of illnesses, particularly cancer and neurological disorders. However, a unique magnetic setup is required in each application for an effective magnetically guided drug aiming to direct the drug-carrying nanocarriers to the intended area. The current and future perspectives of MDDS are investigated in this study by considering their biological functions, deliverable efficiency, complexity, and the nature of the externally applied magnetic field. Despite the fact that MDDSs have low cytotoxicity, regulated magneto reactivity, extended circulation lifespan, and high surface stability, very few clinical studies have been conducted to date in order to achieve optimized therapeutic efficacy before entering the market. In recent studies, the development of novel magnetic medication transporting carriers is preferred over direct magnetic medication administration. Better functional magnetic targeting technologies are required for such breakthroughs to enter clinical trials. Because MDDSs are unlikely to work in all clinical situations, more focused research is needed to replace or improve the strategy for treating multiple illnesses. 相似文献
144.
Muhammad Junaid Iqbal Khan Zarfishan Kanwal Masood Yousaf Hamid Ullah Javed Ahmad Abid Latif Yong-Han Shin Ata Ur Rahman Khalid 《理论物理通讯》2021,73(3):35701-147
The development of new materials,having exceptional properties in comparison to existing materials is highly required for bringing advancement in electronic and optoelectronic technologies.Keeping this fact,we investigated structural,electronic,and optical properties of zincblende GaN doped with selected Zn concentrations(6.25%,12.50%,and 18.70%),using the first-principle calculations based on density functional theory with GGA+U.We conducted the entire study using the WIEN2K code.In this study,we calculated various significant parametric quantities such as cohesive energies,formation energies,bulk moduli,and lattice constants along with the study of optical and electronic properties by substituting Ga atoms with Zn atoms in 1×2×2 supercell.The structural stability is confirmed by studying the phonon dispersion curves which suggest that Zn:GaN material is stable against the 6.25%and 18.70%Zn concentrations while for 12.50%,it shows instability.The Hubbard values U=0,2,4,6 eV were added to GGA and the electronic properties were improved with the U=6 eV.Optical absorption was blue shifted while the refractive index and dielectric constant were increased with increasing the Zn concentrations.Electronic properties are enhanced due to the prime contribution of cations(Zn)3ri states.The optical and electronic properties are further discussed in detail in the entire study. 相似文献
145.
Siqi Yan Tong Tong Yue Li Shifa Ullah Khan Jing Zhao Shengtian Wang Xiaohong Wang 《Catalysis Surveys from Asia》2017,21(4):151-159
High proton content polytungstoboronic acid H7BW11TiO40 (abbreviated as H7BW11Ti) had been prepared through titanium mono-substituted of H5BW12O40, which was evaluated in esterification of palmitic acid with methanol. H7BW11Ti could promote esterification reaction with almost 100% conversion of 417 mol/mol h TOF within very short time of 1 h at methanol/acid ratio of 25:1 under reaction temperature of 65?°C, which was attributed to the higher Brønsted acidity and cooperation of Lewis acidic site generating from Ti substituent. Limitation by its homogeneous performance, solidification of H7BW11Ti was designed via partial exchanging protons with choline cation (abbreviated as Ch+) to prepare a series of [(CH3)3NCH2CH2OH]nH7?nBW11TiO40 (abbreviated as ChnH7?nBW11Ti, n?=?0?~?7). Among all solid catalysts, the highest efficiency had been achieved by with 99.0% conversion and 429 mol/mol h TOF within 50 min at 65?°C at methanol/acid ratio of 15:1. The comparable activity was attributed to the cooperation of Ch+—self-assembling to form nanoreactor with amphiphilic surrounding to concentrate substrates and to resist to water-poison, temperature-responsive property to control form changing between heterogeneous to homogenous. This temperature-responsive HPA catalyst was available for production of biodiesel through esterification reaction. In addition, Separation of such heteropolyacid catalysts was easy by the lowering the reaction temperature to room temperature without appreciable loss of its high performance, which were reused for more than six times. 相似文献
146.
MUHAMMAD Nadeem Arshad TARIQ Mahmood ATHER Faroque Khan MUHAMMAD Zia-Ur-Rehman ABDULLAH M.Asiri ISLAM Ullah Khan RIFFAT-Un-Nisa KHURSHID Ayub AZAM Mukhtar MUHAMMAD Tariq Saeed 《结构化学》2015,34(1):15-25
1,2-Benzothiazine derivatives methyl 3-methoxy-4-oxo-3,4-dihydro-2H-benzo[e] [1,2]thiazine-3-carboxylate 1,1-dioxide(1) and methyl 2-ethyl-3-hydroxy-4-oxo-3,4-dihydro-2Hbenzo[e][1,2]thiazine-3-carboxylate 1,1-dioxide(2) were synthesized, and characterized by spectroscopic techniques; 1H-NMR and infrared(IR) spectroscopy. Crystals of 1 and 2 were grown by slow evaporation of methanol and ethyl acetate, respectively and their crystal structures were investigated by single-crystal X-ray diffraction analysis. Geometric properties were calculated by the B3 LYP method of density functional theory(DFT) at the 6-31G+(d) basis set to compare with the experimental data. Simulated properties were found in strong agreement with the experimental ones. Intermolecular forces have also been modeled in order to investigate the strength of packing and strong hydrogen bonding was observed in both compounds 1 and 2. Electronic properties such as Ionization Potential(IP), Electron Affinities(EA) and coefficients of the highest occupied molecular orbital(HOMO) and the lowest unoccupied molecular orbital(LUMO) of com- pounds 1 and 2 were simulated for the first time. 相似文献
147.
A pair of enatiomerically pure ligands,(R-)/(S-)2-(4-carboxyphenyl)-4,5-dihydrothiazole-4-carboxylic acid(H2L^R & H2L^S), have been synthesized by the reactions of 4-cyanobenzoic acid with L-and D-cysteine, respectively. Four coordination polymers have been prepared from the ligands and structurally determined by single-crystal X-ray diffraction analysis. Complexes 1 R and 1 S([NiL(Py)(H2 O)]×H2 O, for 1 R, L =(L^R)2-;for 1 S, L =(L^S)2-) exhibit chiral helical one-dimensional chains, and complexes 2 R and 2 S({[ZnL2(H2 O)3]×CH3 CN}n, for 2 R L =(L^R)2-, for 2 S L =(LS)2-) are two-dimensional sheets. Luminescent and chir-optical properties have been investigated and compared with the free ligands. The complexes have blue-shift in luminescence spectrum compared with the free ligands. 相似文献
148.
Amir Zada Nauman Ali Muhammad Ateeq Ali M. Huerta-Flores Zahid Hussain Shabana Shaheen Mohib Ullah Sharafat Ali Imran Khan Wajid Ali Muhammad Ishaq Ali Shah Waliullah Khan 《中国化学会会志》2020,67(6):983-989
Energy crises and environmental pollution have sparked tremendous research work to handle their impacts. Herein, we fabricated Au/g-C3N4 nanocomposites to produce H2 and degrade 2,4-dichlorophenol (2,4-DCP) under visible light and at different wavelengths. Interestingly, the optimized photocatalyst generated 114 μmol H2 and degraded 25% 2,4-DCP in 1 hr as compared with 10 μmol H2 generation and 8% 2,4-DCP degradation by pure g-C3N4. This improvement is credited to the extended light absorption and improved charge induction from gold to g-C3N4 even at 590 nm as confirmed from photoluminescence, surface photovoltage, and photoelectrochemical study of the samples. Moreover, the surface catalytic property of g-C3N4 was much improved after loading a proper amount of gold nanoparticles. We hope that this technique to photosensitize semiconductors with noble metal nanoparticles may provide a feasible way to construct surface plasmon resonance-assisted photocatalysts to cope with energy crises and environmental pollution simultaneously. 相似文献
149.
Hussain J Ullah R Khan A Khan FU Muhammad Z Shah MR 《Natural product communications》2011,6(2):171-173
A new tricyclic clerodane-type diterpenoid, trivially named phlomeoic acid (1), was isolated from the methanolic extract of Phlomis bracteosa, together with two known compounds, ursolic acid and glutinol, isolated for the first time from this species. Their structures were elucidated by means of spectroscopic and mass spectrometric techniques and comparison with literature data. 相似文献
150.
Shakir M Azam M Ullah MF Hadi SM 《Journal of photochemistry and photobiology. B, Biology》2011,104(3):449-456
A novel tetradentate Cu(II) complex of the type, [CuL](NO(3))(2) was synthesized by the interaction of Schiff base ligand, N,N-bis[(E)-2-thienylmethylidene]-1,8-naphthalenediamine, L obtained by the condensation of thiophene-2-carboxaldehyde and 1,8-diaminonaphthalene. The formation of Schiff base ligand, L and its Cu(II) complex was confirmed on the basis of results of elemental analyses, mass, FT-IR, (1)H and (13)C{(1)H} NMR spectral studies. UV-Vis, EPR and magnetic susceptibility data support a square planar environment around Cu(II) ion. However, molar conductance values confirmed 1:2 electrolytic nature for the Cu(II) complex. The electrochemical studies of Cu(II) complex was carried out by using cyclic voltammetry which revealed the complex to exhibit quasi reversible process. The biological activity of Cu(II) complex such as ability to bind DNA and DNA cleavage were studied where the Cu(II) complex was shown to cause considerable DNA cleavage and also generated reactive oxygen species such as superoxide anion. Since it is known that various anticancer drugs act through induction of oxidative stress that is mediated by reactive oxygen species, our results suggest a putative role of Cu(II) complex similar to various anticancer drugs. 相似文献