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21.
Irum Shahzadi Ameer F. Zahoor Azhar Rasul Nasir Rasool Zohaib Raza Shahla Faisal Bushra Parveen Shagufta Kamal Muhammad Zia-ur-Rehman Faisal M. Zahid 《Journal of heterocyclic chemistry》2020,57(7):2782-2794
Theophylline-7-acetic acid (acefylline) ( 3 ) and its derivatives are pharmacologically active compounds and generally recognized as bronchodilators for the treatment of respiratory diseases like acute asthma for over 70 years. In this article, synthesis of 2-((5-((1,3-dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-yl)thio)-N-arylacetamides ( 10a-j ) has been reported. All the synthesized derivatives ( 10a-j) were structurally verified by FT-IR, 1H NMR, 13C NMR and evaluated for their anti-cancer (using MTT assay), hemolytic and thrombolytic potential. N-(4-Chlorophenyl)-2-(5-((1,3-dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-ylthio)acetamide ( 10g ) was found to be the most active against human liver cancer cell lines (Huh7) having cell viability 53.58 ± 1.28 using 100 μg/mL concentration of compound which was further in-silico modelled to describe the possible mechanistic insights for its anti-proliferative activity. The results of hemolytic and thrombolytic activities indicated that these derivatives were less toxic and hold considerable potential as a drug candidate. 2-(5-((1,3-Dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-ylthio)-N-(2-fluorophenyl)acetamide ( 10c ) of the series was found to be least toxic with 0.1% hemolysis relative to ABTS (95.5%) as positive control. 2-(5-((1,3-Dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-ylthio)-N-(tetrahydro-2H-pyran-4-yl)acetamide ( 10j ) exhibited potent clot lysis activity (90%) as compared to negative control DMSO (0.57%). 相似文献
22.
Sajid Muhammad Munir Shad Naveed Akthar Javed Yasir Khan Sadaf Bashir Zhang Zhengjun Amin Nasir 《Research on Chemical Intermediates》2020,46(2):1201-1215
Research on Chemical Intermediates - We prepared unique BiVO4/reduce graphene oxide (BiVO4/rGO) nanocomposite with enhanced photocatalytic ability by hydrothermal method applying... 相似文献
23.
Nasir Ahmad Nasir Iqbal Christy Munir 《Monatshefte für Chemie / Chemical Monthly》2000,124(3):1067-1072
The synthesis and characterization of homobimetallic complexes of VO(IV), Cr(II), Co(II), Ni(II), and Cu(II) with the chiral Schiff base (1S,2S)-N,N-1,2-Diphenylethylene-bis-(5-imino-1-phenyl-1,3-hexa-nedione) is reported. The metal ions occupy both compartments of the ligand; water molecules fill the coordination spheres to provide an octahedral environment around the central atoms. The antibacterial activity of both mono- and bimetallic complexes against a number of Gram-positive as well as Gram-negative bacteria has been tested and is discussed. 相似文献
24.
Dr. Sara Sabater Dr. David Schmidt Dr. Heidi Schmidt Dr. Maximilian W. Kuntze-Fechner Dr. Thomas Zell Connie J. Isaac Dr. Nasir A. Rajabi Harry Grieve Dr. William J. M. Blackaby Dr. John P. Lowe Prof. Stuart A. Macgregor Dr. Mary F. Mahon Prof. Dr. Udo Radius Prof. Michael K. Whittlesey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(52):13221-13234
The addition of PPh2H, PPhMeH, PPhH2, P(para-Tol)H2, PMesH2 and PH3 to the two-coordinate Ni0 N-heterocyclic carbene species [Ni(NHC)2] (NHC=IiPr2, IMe4, IEt2Me2) affords a series of mononuclear, terminal phosphido nickel complexes. Structural characterisation of nine of these compounds shows that they have unusual trans [H−Ni−PR2] or novel trans [R2P−Ni−PR2] geometries. The bis-phosphido complexes are more accessible when smaller NHCs (IMe4>IEt2Me2>IiPr2) and phosphines are employed. P−P activation of the diphosphines R2P−PR2 (R2=Ph2, PhMe) provides an alternative route to some of the [Ni(NHC)2(PR2)2] complexes. DFT calculations capture these trends with P−H bond activation proceeding from unconventional phosphine adducts in which the H substituent bridges the Ni−P bond. P−P bond activation from [Ni(NHC)2(Ph2P−PPh2)] adducts proceeds with computed barriers below 10 kcal mol−1. The ability of the [Ni(NHC)2] moiety to afford isolable terminal phosphido products reflects the stability of the Ni−NHC bond that prevents ligand dissociation and onward reaction. 相似文献
25.
The cyclization of the dianions of diethyl 2-oxopropylphosphonate and of acetone with 1,1-diacylopropanes afforded hydroxyspiro[5.2]cyclooctenones which were transformed, by homo-Michael reactions with tetrabutylammonium halides, into various functionalized phenols or their dimers. 相似文献
26.
The effect of variable viscosity on the peristaltic flow of a Newtonian fluid in an asymmetric channel has been discussed. Asymmetry in the flow is induced due to travelling waves of different phase and amplitude which propagate along the channel walls. A long wavelength approximation is used in the flow analysis. Closed form analytic solutions for velocity components and longitudinal pressure gradient are obtained. The study also shows that, in addition to the effect of mean flow parameter, the wave amplitude also effect the peristaltic flow. This effect is noticeable in the pressure rise and frictional forces per wavelength through numerical integration. 相似文献
27.
Krzysztof Pomorski José M. Blanco Pavel V. Kostryukov Artur Dobrowolski Bo?ena Nerlo-Pomorska Micha? Warda Zhi-Gang Xiao Yong-Jing Chen Li-Le Liu Jun-Long Tian Xin-Yue Diao Qiang-Hua Wu 《中国物理C(英文版)》2021,45(5):054109-054109-11
Fission properties of the actinide nuclei are deduced from theoretical analysis. We investigate potential energy surfaces and fission barriers and predict the fission fragment mass yields of actinide isotopes. The results are compared with experimental data where available. The calculations were performed in the macroscopic-microscopic approximation with the Lublin-Strasbourg Drop (LSD) for the macroscopic part, and the microscopic energy corrections were evaluated in the Yukawa-folded potential. The Fourier nuclear shape parametrization is used to describe the nuclear shape, including the non-axial degree of freedom. The fission fragment mass yields of the nuclei considered are evaluated within a 3D collective model using the Born-Oppenheimer approximation. 相似文献
28.
Navida Nasir Andriy Grytsiv Gerald Giester Gerhard E. Nauer 《Journal of solid state chemistry》2010,183(3):565-574
Phase relations were established in the Sr-poor part of the ternary systems Sr-Ni-Si (900 °C) and Sr-Cu-Si (800 °C) by light optical microscopy, electron probe microanalysis and X-ray diffraction on as cast and annealed alloys. Two new ternary compounds SrNiSi3 (BaNiSn3-type) and SrNi9−xSi4+x (own-type) were found in the Sr-Ni-Si system along with previously reported Sr(NixSi1−x)2 (AlB2-type). The crystal structure of SrNi9−xSi4+x (own-type, x=2.7, a=0.78998(3), c=1.1337(2) nm; space group P4/nbm) was determined from X-ray single crystal counter to be a low symmetry derivative of the cubic, parent NaZn13-type. At higher Si-content X-ray Rietveld refinements reveal the formation of a vacant site (□) corresponding to a formula SrNi5.5Si6.5□1.0. Phase equilibria in the Sr-Cu-Si system are characterized by the compounds SrCu2−xSi2+x (ThCr2Si2-type), Sr(CuxSi1−x)2 (AlB2-type), SrCu9−xSi4+x (0≤x≤1.0; CeNi8.5Si4.5-type) and SrCu13−xSix (4≤x≤1.8; NaZn13-type). The latter two structure types appear within a continuous solid solution. Neither a type-I nor a type-IX clathrate compound was encountered in the Sr-{Cu,Ni}-Si systems.Structural details are furthermore given for about 14 new ternary compounds from related alloy systems with Ba. 相似文献
29.
Navida Nasir Nataliya Melnychenko-Koblyuk Ingeborg Bednar 《Journal of solid state chemistry》2010,183(10):2329-2342
Three series of vacancy-free quaternary clathrates of type I, Ba8ZnxGe46−x−ySiy, Ba8(Zn,Cu)xGe46−x, and Ba8(Zn,Pd)xGe46−x, have been prepared by reactions of elemental ingots in vacuum sealed quartz at 800 °C. In all cases cubic primitive symmetry (space group Pm3?n, a∼1.1 nm) was confirmed for the clathrate phase by X-ray powder diffraction and X-ray single crystal analyses. The lattice parameters show a linear increase with increase in Ge for Ba8ZnxGe46−x−ySiy. M atoms (Zn, Pd, Cu) preferably occupy the 6d site in random mixtures. No defects were observed for the 6d site. Site preference of Ge and Si in Ba8ZnxGe46−x−ySiy has been elucidated from X-ray refinement: Ge atoms linearly substitute Si in the 24k site whilst a significant deviation from linearity is observed for occupation of the 16i site. A connectivity scheme for the phase equilibria in the “Ba8Ge46” corner at 800 °C has been derived and a three-dimensional isothermal section at 800 °C is presented for the Ba-Pd-Zn-Ge system. Studies of transport properties carried out for Ba8{Cu,Pd,Zn}xGe46−x and Ba8ZnxSiyGe46−x−y evidenced predominantly electrons as charge carriers and the closeness of the systems to a metal-to-insulator transition, fine-tuned by substitution and mechanical processing of starting material Ba8Ge43. A promising figure of merit, ZT ∼0.45 at 750 K, has been derived for Ba8Zn7.4Ge19.8Si18.8, where pricey germanium is exchanged by reasonably cheap silicon. 相似文献
30.
Fission cross sections strongly depend on the ratio of the level density parameter in fission to neutron emission, af/an. In this work, a cascade-exciton model implemented in the code CEM95 has been used to observe this effect for proton induced fission cross sections of tungsten, lead and bismuth. The method was employed using different level density parameter ratios for each fission cross section calculation. The calculated fission cross sections are compared with the available experimental data in the literature. It has been observed that a change of the ratio of the level density parameter, af/an, is necessary with the incident energy of the proton, to best estimate the fission cross sections in CEM95. 相似文献