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81.
Sarosh Iqbal Nimra Naveed Shaikh Khalid Mohammed Khan Shumaila Kiran Sehrish Naz Zaheer Ul-Haq Shahnaz Perveen M. Iqbal Choudhary 《Molecules (Basel, Switzerland)》2022,27(22)
Currently the discovery and development of potent β-glucuronidase inhibitors is an active area of research due to the observation that increased activity of this enzyme is associated with many pathological conditions, such as colon cancer, renal diseases, and infections of the urinary tract. In this study, twenty-seven 2-aminopyrimidine derivatives 1–27 were synthesized by fusion of 2-amino-4,6-dichloropyrimidine with a variety of amines in the presence of triethylamine without using any solvent and catalyst, in good to excellent yields. All synthesized compounds were characterized by EI-MS, HREI-MS and NMR spectroscopy. Compounds 1–27 were then evaluated for their β-glucuronidase inhibitory activity, and among them, compound 24 (IC50 = 2.8 ± 0.10 µM) showed an activity much superior to standard D-saccharic acid 1,4-lactone (IC50 = 45.75 ± 2.16 µM). To predict the binding mode of the substrate and β-glucuronidase, in silico study was performed. Conclusively, this study has identified a potent β-glucuronidase inhibitor that deserves to be further studied for the development of pharmaceutical products. 相似文献
82.
Ahmad VU Zubair M Athar Abbasi M Abid Rashid M Rasool N Nahar Khan S Iqbal Choudhary M Kousar F 《Magnetic resonance in chemistry : MRC》2005,43(6):486-488
The investigation of the chemical constituents of Symplocos racemosa Roxb led to the isolation of two new glycosides, symcomoside A (1) and symcomoside B (2), together with one known glycoside, tortoside C (3), which is reported for the first time from this plant. The structures of the new compounds were determined by 1D and 2D homonuclear and heteronuclear NMR spectroscopy, from chemical evidence and by comparison with published data for closely related compounds. Symcomoside B (2) showed potent inhibitory activity against alpha-glucosidase in a concentration-dependent fashion with an IC50 value of 0.733 +/- 0.033 mM whereas symcomoside A (1) showed very weak inhibitory activity against alpha-glucosidase (9.90% in 0.70 mM). 相似文献
83.
Abachi S Abbott B Abolins M Acharya BS Adam I Adams DL Adams M Ahn S Aihara H Alitti J Álvarez G Alves GA Amidi E Amos N Anderson EW Aronson SH Astur R Avery RE Baden A Balamurali V Balderston J Baldin B Bantly J Bartlett JF Bazizi K Bendich J Beri SB Bertram I Bezzubov VA Bhat PC Bhatnagar V Bhattacharjee M Bischoff A Biswas N Blazey G Blessing S Boehnlein A Bojko NI Borcherding F Borders J Boswell C Brandt A Brock R Bross A Buchholz D Burtovoi VS Butler JM Casey D Castilla-Valdez H 《Physical review letters》1995,75(4):618-623
84.
Polycrystalline samples of Pb(Mg1/4Zn1/4Nb1/2)O11/4 have been synthesized by high temperature columbite precursor solid state reaction technique. Using X-ray diffraction (XRD)
technique, compound formation in single phase cubic structure was observed and XRD analysis provided preliminary structural
data. Detailed studies of dielectric properties of the compound reveal that this compound has high dielectric constant and
diffuse phase transition in a wide range of temperatures around the Curie temperature. The charge deficiency of the compound
presumably gets compensated in the high temperature columbite precursor process of sample preparation which is supported by
single phasic form of the material. 相似文献
85.
Vasant R. Choudhary Subhabrata Banerjee Suryakant G. Pataskar 《Journal of Chemical Sciences》2003,115(4):287-298
Combustion of dilute propane (0.9 mol%) over Mn-doped ZrO2 catalysts prepared using different precipitating agents (viz. TMAOH, TEAOH, TPAOH, TBAOH and NH4OH), having different Mn/Zr ratios (0.05—0.67) and calcined at different temperatures (500—800°C), has been thoroughly investigated
at different temperatures (300—500°C) and space velocities (25,000–100,000 cm3 g−1 h−1) for controlling propane emissions from LPG-fuelled vehicles. Mn-doped ZrO2 catalyst shows high propane combustion activity, particularly when its ZrO2 is in the cubic form, when its Mn/Zr ratio is close to 0.2 and when it is prepared using TMAOH as a precipitating agent and
calcined at 500—600°C. Pulse reaction of propane in the absence of free-O2 over Mn-doped ZrO2 (cubic) and Mn-impregnated ZrO2 (monoclinic) catalysts has also been investigated for studying the relative reactivity and mobility of the lattice oxygen
of the two catalysts. Both reactivity and mobility of the lattice oxygen of Mn-doped ZrO2 are found to be much higher than that of Mnimpregnated ZrO2. Propane combustion over Mn-doped ZrO2 catalyst involves a redox mechanism 相似文献
86.
Smrati Gupta Dirk Kuckling Katja Kretschmer Veena Choudhary Hans‐Jürgen Adler 《Journal of polymer science. Part A, Polymer chemistry》2007,45(4):669-679
The aim of this work was the development of a versatile route for the preparation of temperature‐ and pH‐responsive hydrogels with small dimensions. The copolymerization of N,N‐dimethylaminoethyl methacrylate with various amounts (5 and 10 mol %) of dimethylmaleimidoethyl methacrylate in solution with 2,2′‐azobisisobutyronitrile as an initiator is described. The structural and molecular characterization of the copolymers was performed with proton nuclear magnetic resonance, Fourier transform infrared, and ultraviolet spectroscopy, as well as size exclusion chromatography. Differential scanning calorimetry and thermogravimetry were used for the thermal characterization of the copolymers. Micro‐ and nanohydrogels of the copolymers were prepared by photocrosslinking. The gels obtained by photocrosslinking were characterized with a combination of surface plasmon resonance and optical waveguide spectroscopy, dynamic light scattering, and scanning electron microscopy. The hydrogels showed temperature‐ and pH‐responsive behavior. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 669–679, 2007 相似文献
87.
J.S. Yadav B.V. Subba Reddy D.N. Chaya G.G.K.S. Narayana Kumar S. Aravind A.C. Kunwar C. Madavi 《Tetrahedron letters》2008,49(20):3330-3334
4-Iodopiperidines are prepared in good yields and with high selectivity by means of aza-Prins-cyclization using a catalytic amount of gallium(III) iodide and a stoichiometric amount of iodine under mild reaction conditions. This is the first report on the preparation of 4-iodopiperidines via aza-Prins-cyclization. 相似文献
88.
P. G. Oza H. S. Mazumdar A. K. Choudhary K. Gopalan 《Journal of Chemical Sciences》1984,93(2):189-193
A microcomputer system has been designed for semi-automatic operation of a solid source mass spectrometer used for geochronological
studies. It sequentially steps the magnetic field through pre-selected values, reads the digitized ion currents for a given
time and temporarily stores the data which can be transferred to a paper tape or directly to a desk top calculator for further
analysis. The unit is relatively inexpensive, made of readily available components and can be adapted to many laboratory automation
tasks 相似文献
89.
The monoclinic crystal structure of NaH2PO4 at room temperature has been refined from neutron-diffraction measurements on a single-crystal sample and complied with the closely related structure of monoclinic KD2PO4. Attention is paid to the information obtained from these two structures about the geometry of hydrogen (deuterium) bonds ?2.6 A. 相似文献
90.
Choudhary MI Musharraf SG Siddiqui ZA Khan NT Ali RA Ur-Rahman A 《Chemical & pharmaceutical bulletin》2005,53(8):1011-1013
The microbial transformation of an oral contraceptive, mestranol (1) by Cunninghamella elegans yielded two hydroxylated metabolites, 6beta-hydroxymestranol (2) and 6beta,12beta-dihydroxymestranol (3). Metabolite 3 was found to be a new compound. These metabolites were structurally characterized on the basis of spectroscopic techniques. 相似文献