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41.
Cancer is the most devastating disease and second leading cause of death around the world. Despite scientific advancements in the diagnosis and treatment of cancer which can include targeted therapy, chemotherapy, endocrine therapy, immunotherapy, radiotherapy and surgery in some cases, cancer cells appear to outsmart and evade almost any method of treatment by developing drug resistance. Quinazolines are the most versatile, ubiquitous and privileged nitrogen bearing heterocyclic compounds with a wide array of biological and pharmacological applications. Most of the anti-cancer agents featuring quinazoline pharmacophore have shown promising therapeutic activity. Therefore, extensive research is underway to explore the potential of these privileged scaffolds. In this context, a molecular hybridization approach to develop hybrid drugs has become a popular tool in the field of drug discovery, especially after witnessing the successful results during the past decade. Histone deacetylases (HDACs) have emerged as an important anti-cancer target in the recent years given its role in cellular growth, gene regulation, and metabolism. Dual inhibitors, especially based on HDAC in particular, have become the center stage of current cancer drug development. Given the growing significance of dual HDAC inhibitors, in this review, we intend to compile the development of quinazoline based HDAC dual inhibitors as anti-cancer agents. 相似文献
42.
43.
The interaction of nitric oxide with single-crystal surfaces of alumina at temperatures of 298, 473, and 673 K, which had been covered by various amounts of iron, was studied using X-ray photoelectron spectroscopy. The iron was deposited onto Al2O3 in the Fe0 state. At low coverages, iron was partially oxidized due to its interaction with Al2O3. Scanning auger mapping analysis showed that the iron was randomly distributed on the Al2O3 surface. The amount of adsorbed NO increased with increasing iron coverage. However, at very high iron coverages, there was a decrease in adsorption. This indicated that the aluminum ions may have activated the NO adsorption on the iron atoms. For increasing temperature there was also an increase in adsorption for high iron coverages, but the adsorption decreased with increasing temperature for low iron coverages. Sticking probability calculations indicated that the adsorption was mobile and dissociative. Binding energy of the nitrogen peaks indicated that NO was adsorbed onto the Fe/Al2O3 surface as a nitride. 相似文献
44.
A Copper‐Based Metal–Organic Framework Acts as a Bifunctional Catalyst for the Homocoupling of Arylboronic Acids and Epoxidation of Olefins 下载免费PDF全文
Srinivasulu Parshamoni Jyothi Telangae Suresh Sanda Prof. Dr. Sanjit Konar 《化学:亚洲杂志》2016,11(4):540-547
A copper(I)‐based metal–organic framework ({[Cu2Br2(pypz)]n?nH2O} (Cu—Br–MOF) [pypz=bis[3,5‐dimethyl‐4‐(4’‐pyridyl)pyrazol‐1‐yl] methane] has been synthesized by using an elongated and flexible bridging ligand. The structure analysis reveals that each pypz ligand acts as a tritopic ligand connected to two Cu2Br2 dimeric units, forming a one‐dimensional zig–zag chain, and these chains further connected by a Cu2Br2 unit, give a two‐dimensional framework on the bc‐plane. In the Cu2Br2 dimeric unit, the copper ions are four coordinated, thereby possessing a tetrahedral geometry; this proves to be an excellent heterogeneous catalyst for the aerobic homocoupling of arylboronic acids under mild reaction conditions. This method requires only 3 mol % of catalyst and it does not require any base or oxidant—compared to other conventional (Cu, Pd, Fe, and Au) catalysts—for the transformation of arylboronic acids in very good yields (98 %). The shape and size selectivity of the catalyst in the homocoupling was investigated. The use of the catalyst was further extended to the epoxidation of olefins. Moreover, the catalyst can be easily separated by simple filtration and reused efficiently up to 5 cycles without major loss of reactivity. 相似文献
45.
Yarram Narasimha Reddy Tenkayala Navya Kumari Pradeepkumar Thota Perla Jyothi Ajay Kumar Gupta 《Tetrahedron letters》2018,59(2):160-162
A new chemoenzymatic route for the preparation of cryptocaryalactones natural products using a kinetic resolution process as the key step is described. Novozyme-435 catalyzed hydrolysis of the prochiral (±)-monoester 7 afforded the precursors of cryptocaryalactones with high enantiomeric excess and excellent yields. The compounds (4S,6S)-7 and (4R,6R)-7 were converted to (+)-(6R,2′S)-cryptocaryalactone (1) and (?)-(6S,2′R)-cryptocaryalactone (2), respectively by employing Wittig-olefination, lactonization and acylation reactions. 相似文献
46.
Balasubramanian?Ranjani Jayaprakasham?Kalaiyarasi Loganathan?Pavithra Thiyagarajan?Devasena Kannaiyan?PandianEmail author Subash?C.?B.?GopinathView authors OrcID profile 《Mikrochimica acta》2018,185(3):194
A sensing device was constructed for the amperometric determination of nitrite. It is based on the use of titanium dioxide (TiO2) nanotubes template with natural fibers and carrying hemin acting as the electron mediator. A glassy carbon electrode (GCE) was modified with the hemin/TNT nanocomposite. The electrochemical response to nitrite was characterized by impedance spectroscopy and cyclic voltammetry. An amperometric study, performed at a working potential of + 0.75 V (vs. Ag/AgCl), showed the sensor to enable determination of nitrite with a linear response in the 0.6 to 130 μM concentration range and with a 59 nM limit of detection. Corresponding studies by differential study voltammetry (Ep?=?0.75 V) exhibited a linear range from 0.6?×?10?6 to 7.3?×?10?5 M with a limit of detection of 84 nM. The sensing device was applied to the determination of nitrite in spiked tap and lake water samples. 相似文献
47.
The extraction characteristics of some selected metals from an aqueous buffered solution by LIX51. a fluorinated commercial
β-diketone extractant, have been investigated. The pH 1/2 (pH at which 50% of the metal ion is extracted) and the logK
ex
values for the extracted metals by 5% (v/v) L1X51 in methylisobutylkctone(MIBK) have been obtained. The order of extraction
of metals with LIX51 as a function of pH 1/2 value is: Cu(II) < Pd(II) < Co(II) < Zn(II) < Fe(H) < Ph(II) < Mn(II) < Cd(II)
< Ni(II). 相似文献
48.
An explicit realization of anyons is provided, using the three-body Calogero model. The fact that in the coupling domain, -1/4<g<0, the angular spectrum can have a band structure, leads to the manifestation of the desired phase in the wave function, under the exchange of particles. Concurrently, the momentum corresponding to the angular variable is quantized, exactly akin to the relative angular momentum quantization in two dimensional anyonic system. 相似文献
49.
M. Siva Pratap Reddy V. Rajagopal Reddy I. Jyothi Chel‐Jong Choi 《Surface and interface analysis : SIA》2011,43(9):1251-1256
Schottky rectifiers are fabricated on n‐type GaN using Ni/Pd metallization scheme and its characteristics have been investigated by current‐voltage (I‐V), Capacitance‐Voltage (C‐V), X‐Ray Diffraction (XRD) and SIMS measurements as a function of annealing temperature. The calculated Schottky barrier height of the as‐deposited contact was found to be 0.60 eV (I‐V), 0.71 eV (C‐V) with an ideality factor of 1.44. However, the barrier height slightly increases after annealing at 300, 400 and 500 °C. On the basis of the experimental results, a high‐quality Schottky contact with barrier height and ideality factor of 0.81 eV (I‐V), 0.88 eV (C‐V) and 1.13 respectively, can be obtained after annealing at 600 °C for 1 min in a nitrogen atmosphere. Further, after annealing at 700 °C, it is found that the barrier height slightly decreased to 0.74 eV (I‐V) and 0.85 eV (C‐V). From the above observations, one can note that Ni/Pd Schottky contact exhibits excellent electrical properties after a rapid thermal annealing at 600 °C. According to the SIMS and XRD analysis, the formation of gallide phases at the Ni/Pd/n‐GaN interface could be the reason of the barrier height increase at elevated annealing temperatures. The Atomic Force Microscopy (AFM) results show that the overall surface morphology of Ni/Pd Schottky contacts on n‐GaN is fairly smooth. The above observations reveal that Ni/Pd Schottky metallization scheme was a good choice for the fabrication of high‐temperature and high‐power device applications. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
50.
Thirugnanasambandan Sivaranjani Manogaran Ranjani Thirugalathi Anbalagan Revathy Vengidusamy Narayanan Arumainathan Stephen 《Research on Chemical Intermediates》2020,46(7):3383-3396
Research on Chemical Intermediates - Blending of two metals possessing localized surface plasmon resonance (LSPR) alters the optical behavior and aids in tuning the resonance frequency of... 相似文献