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排序方式: 共有221条查询结果,搜索用时 234 毫秒
1.
2.
Anil M. Shelke Varun Rawat Gurunath Suryavanshi Arumugam Sudalai 《Tetrahedron: Asymmetry》2012,23(22-23):1534-1541
A new enantioselective synthesis of two important fungal metabolites, (+)-stagonolide C and (?)-aspinolide A, has been described from readily available raw materials. Proline catalyzed asymmetric α-aminooxylation and Jorgensen’s epoxidation of aldehydes are the key reactions employed in the introduction of chirality. The formation of the 10-membered lactone core structure was finally accomplished via Steglich esterification and ring closing metathesis reactions. 相似文献
3.
Some new biologically potent coumarin derivatives 7a–f, 8a–f, and 9a–f bearing modified pyridine moieties (indeno[1,2-b]pyridine, 4-azaphenanthrene and benzofuro [3,2-b]pyridine) at the sixth position were designed and synthesized. All the synthesized compounds were assayed for their antimicrobial efficiency against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhi, Candida albicans, and Aspergillus niger. Most of the compounds showed appreciable antimicrobial activity against the tested strains. Compounds 8b, 8c, 9b, 9d, and 9f emerged as most proficient members of the series. The antitubercular activity for all the synthesized compounds was performed against Mycobacterium tuberculosis H37Rv. Compounds 8f, 9b, and 9f exhibited promising antitubercular activity. Consequently, synthesized derivatives were found to be worthy of further investigation. 相似文献
4.
Yogesh K. Vohra Gopi K. Samudrala Samuel L. Moore Jeffrey M. Montgomery Georgiy M. Tsoi Nenad Velisavljevic 《高压研究》2015,35(3):282-288
Ultra-high static pressures have been achieved in the laboratory using a two-stage micro-ball nanodiamond anvils as well as a two-stage micro-paired diamond anvils machined using a focused ion-beam system. The two-stage diamond anvils’ designs implemented thus far suffer from a limitation of one diamond anvil sliding past another anvil at extreme conditions. We describe a new method of fabricating two-stage diamond micro-anvils using a tungsten mask on a standard diamond anvil followed by microwave plasma chemical vapor deposition (CVD) homoepitaxial diamond growth. A prototype two-stage diamond anvil with 300?µm culet and with a CVD diamond second stage of 50?µm in diameter was fabricated. We have carried out preliminary high pressure X-ray diffraction studies on a sample of rare-earth metal lutetium sample with a copper pressure standard to 86?GPa. The micro-anvil grown by CVD remained intact during indentation of gasket as well as on decompression from the highest pressure of 86?GPa. 相似文献
5.
Varun A. Morde Mushtaque S. Shaikh Raghuvir R. S. Pissurlenkar Evans C. Coutinho 《Molecular diversity》2009,13(4):501-517
The search for new antimalarial agents is necessary as current drugs in the market become vulnerable due to the emergence
of resistance strains of Plasmodium falciparum (P. falciparum). The biosynthetic pathway for fatty acids has been recognized and validated as an important drug target in P.falciparum. One of the important enzymes in this pathway that has a determinant role in completing the cycles of chain elongation is
Enoyl-ACP reductase (ENR) also popularly known as FabI. In this paper we report the design, synthesis, and microbial evaluation of inhibitors of Plasmodium enoyl reductase (PfENR). The search for inhibitors involved a virtual screening of the iResearch database with docking simulations. One of the
hits was selected and modified to optimize its binding to PfENR; this resulted in the development of analogues of N-benzylidene-4-phenyl-1,3-thiazol-2-amine. The activity of these analogues was predicted from comparative molecular field
analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) models constructed from a dataset of 43 known
inhibitors of PfENR. The most promising molecules were synthesized and their structures characterized by spectroscopic techniques. The molecules
were screened for in vitro antimalarial activity by whole-cell assay method. Two molecules, viz. VRC-007 and VRC-009, were
found to be active at 4.67 and 7.01 μM concentrations, respectively. 相似文献
6.
The paper reports a structural study of some memory and threshold chalcogenides in terms of coordination numberC, defined byC=8−N, and is the average coordination number for covalently bonded materials. The average number of nearest neighbours surrounding
a central atom, obtained for As-Ge-Te (memory) and Se-Ge-Te (threshold) systems have been used to estimate the cohesive energies,
assuming simple additivity of bond energies. The bonding pattern so obtained, explains certain properties of these glasses. 相似文献
7.
Saroj K. Vohra 《Trends in analytical chemistry : TRAC》1983,2(3):57-62
Classical DC polarography was introduced by Heyrovsky in 1922. Since then substantial advances have been made in the technique, its instrumentation and methodology. These, coupled with the brilliant and innovative thinking of several workers, especially Barker, have transformed polarographic analysis into a powerful analytical tool. 相似文献
8.
Ultrathin nanocrystalline films of gold formed at different temperatures at the organic-aqueous interface have been investigated by X-ray diffraction, electron microscopy, atomic force microscopy, and electronic spectroscopy. The films are smooth and continuous over relatively large length scales and are generally approximately 100 nm thick. The size of the nanocrystals is sensitive to the reaction temperature, which also determines whether the film is metallic or an activated conductor. The surface plasmon band of gold is highly red-shifted in the films. Alkanethiols perturb the structure of the films, with the magnitude of the effect depending on the chain length. Accordingly, the position of the plasmon band and the electrical resistance of the films are affected by interaction with alkanethiols; the plasmon band approaches that of isolated nanocrystals in the presence of long-chain thiols. 相似文献
9.
R. Santhosh Reddy Tanveer Mahamadali Shaikh Varun Rawat Pratibha U. Karabal Gajanan Dewkar Gurunath Suryavanshi Arumugam Sudalai 《Catalysis Surveys from Asia》2010,14(1):21-32
A novel, exceptionally stable titanium superoxide radical ion was prepared and its structure determined by FTIR, ESR, Raman
spectroscopy, X-ray diffraction, thermogravimetric/differential thermal analysis and elemental analysis. This heterogeneous
catalyst has been found to be effective for the selective oxidation of aromatic amines and phenols to the corresponding nitro
aromatics and p-quinones, respectively. In addition, this non-toxic, inexpensive and reusable catalyst has also been used in aminobromination
of olefins, which proceed to give the 1, 2-bromoaminated anti-Markovnikov product. A brief account of these results is summarized in this review. 相似文献
10.