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971.
Raj Kumar Ramagiri 《合成通讯》2014,44(9):1301-1306
A simple and highly efficient one-pot, three-component synthesis of 3-(2-(4-chlorophenylimino)-3-(4-chlorophenyl)-2,3-dihydrothiazol-4-yl)-2H-chromen-2-ones has been reported by the reaction of 3-(2-bromoacetyl)-2H-chromen-2-one, primary amines, and phenyl isothiocyanates in presence of dimethylformamide as a solvent. The structures of newly synthesized compounds were confirmed by their analytical and spectral data. 相似文献
972.
Design of Monodisperse and Well‐Defined Polypeptide‐Based Polyvalent Inhibitors of Anthrax Toxin 下载免费PDF全文
Sanket Patke Mohan Boggara Ronak Maheshwari Sunit K. Srivastava Manish Arha Marc Douaisi Jacob T. Martin Ian B. Harvey Matthew Brier Tania Rosen Jeremy Mogridge Prof. Ravi S. Kane 《Angewandte Chemie (International ed. in English)》2014,53(31):8037-8040
The design of polyvalent molecules, presenting multiple copies of a specific ligand, represents a promising strategy to inhibit pathogens and toxins. The ability to control independently the valency and the spacing between ligands would be valuable for elucidating structure–activity relationships and for designing potent polyvalent molecules. To that end, we designed monodisperse polypeptide‐based polyvalent inhibitors of anthrax toxin in which multiple copies of an inhibitory toxin‐binding peptide were separated by flexible peptide linkers. By tuning the valency and linker length, we designed polyvalent inhibitors that were over four orders of magnitude more potent than the corresponding monovalent ligands. This strategy for the rational design of monodisperse polyvalent molecules may not only be broadly applicable for the inhibition of toxins and pathogens, but also for controlling the nanoscale organization of cellular receptors to regulate signaling and the fate of stem cells. 相似文献
973.
Ashutosh Kumar Buddhadev Purohit Pawan Kumar Maurya Lalit Mohan Pandey Pranjal Chandra 《Electroanalysis》2019,31(9):1615-1629
The design and development of modern biosensors for sensitive and selective detection of various biomarkers is important in diversified arenas including healthcare, environment, and food industries etc. The requirement of more robust and reliant biosensors lead to the development of various sensing modules. The nanomaterials having specific optical, electrical, and mechanical strength can pave the way towards development of ultrafast, robust, and miniaturized modules for biosensors. It can provide not only the point‐of‐care applicability but also has tremendous commercial as well as industrial justification. In order to improve the performance of the sensor systems, various nanostructure materials have been readily studied and applied for development of novel biosensors. In the last few years, researchers are engaged on harnessing the unique atomic and molecular properties of advance‐engineered materials including carbon nanotubes, graphene nanosheets, metal nanoparticles, metal oxide nanoparticles, and their nano‐conjugates. In view of such recent developments in nanomaterial engineering, the current review has been formulated emphasizing the role of these materials in surface engineering, biomolecule conjugation, and signal amplification for development of various ultrasensitive and robust biosensors having commercial as well as industrial viability. Attention is given on the electrochemical biosensors incorporating various nanomaterials and their conjugates. Importance of nanomaterials in the analytical performance of the various biosensor has also been discussed. To put a perceptive insights on the importance of various nanomaterials, an extended table is incorporated, which includes probe design, analyte, LOD, and dynamic range of various electrochemical biosensors. 相似文献
974.
S. Ramalingam S. Periandy M. Govindarajan S. Mohan 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,75(4):1308-1314
In this work, the experimental and theoretical study on molecular structure and vibrational spectra of 4-nitrotoluene are studied. The FTIR and FTRaman experimental spectra of the molecule have been recorded in the range of 4000–100 cm?1. Making use of the recorded data, the complete vibrational assignments are made and analysis of the observed fundamental bands of molecule is carried out. The experimental determinations of vibrational frequencies are compared with those obtained theoretically from ab initio HF and DFT quantum mechanical calculations using HF/6-31G (d, p), B3LYP/6-31++G* (d, p) and B3LYP/6-311++G* (d, p) methods. The differences between the observed and scaled wave number values of most of the fundamentals are very small in B3LYP than HF. The geometries and normal modes of vibrations obtained from ab initio HF and B3LYP calculations are in good agreement with the experimentally observed data. Comparison of the simulated spectra provides important information about the ability of the computational method (B3LYP) to describe the vibrational modes. The vibrations of NO2 and CH3 groups coupled with skeletal vibrations are also investigated. 相似文献
975.
A polyvinyl chloride (PVC) membrane based Pr(III) selective electrode was constructed using 1,6,7,12‐tetramine‐2,5,8,11‐tetraoxo‐1(12),6(7)‐di(biphenyl)dodecane (TATODBDD) as a neutral carrier. The sensor exhibits a Nernstian response for Pr(III) ions, a wide concentration range of 3.9×10?7?1.0×10?1 mol/L with a detection limit of 5.0×10?8 mol/L and slope of 19.5 mV/decade. The developed sensor revealed relatively good selectivity and high sensitivity for Pr(III) ions over the other lanthanide ions. The potentiometric response of the sensor is independent in the pH range 2.9–9.5. The advantages of sensor are low resistance, very fast response time (<10 s) with good selectivity. This sensor can be used up to 6 weeks without any divergences in potential response. 相似文献
976.
Synthesis,antibacterial, and antioxidant activities of naphthyl-linked disubstituted 1,2,3-triazoles
Here, click synthesis of 15 naphthyl-linked disubstituted 1,2,3-triazoles has been carried out by the reaction between 1-(prop-2-yn-1-yloxy)naphthalene and aromatic azides. The structure elucidation of the synthesized compounds was carried out by FTIR, 1H NMR, 13C NMR, and HRMS techniques. Further, the compound 7f was confirmed by X-ray crystallography (CCDC 1876891). The synthesized compounds were explored for antibacterial activity against Bacillus cereus, Escherichia coli, and Staphylococcus aureus. Biological evaluation of synthesized 1,2,3-triazoles revealed moderate to good antibacterial activity against the tested strains. The antioxidative behavior of synthesized compounds manifested the remarkable free radical scavenging activity using DPPH assay. 相似文献
977.
Roy A. M. van Beekveld Maik G. N. Derks Raj Kumar Leanna Smid Thorben Maass Dr. João Medeiros-Silva Dr. Eefjan Breukink Dr. Markus Weingarth 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(70):e202202472
Specific interactions with phospholipids are often critical for the function of proteins or drugs, but studying these interactions at high resolution remains difficult, especially in complex membranes that mimic biological conditions. In principle, molecular interactions with phospholipids could be directly probed by solid-state NMR (ssNMR). However, due to the challenge to detect specific lipids in mixed liposomes and limited spectral sensitivity, ssNMR studies of specific lipids in complex membranes are scarce. Here, by using purified biological 13C,15N-labeled phospholipids, we show that we can selectively detect traces of specific lipids in complex membranes. In combination with 1H-detected ssNMR, we show that our approach provides unprecedented high-resolution insights into the mechanisms of drugs that target specific lipids. This broadly applicable approach opens new opportunities for the molecular characterization of specific lipid interactions with proteins or drugs in complex fluid membranes. 相似文献
978.
Murugavel Saminathan Mohan Raj Jayakumar Ravikumar Chandrasekaran Ranganathan Raja Jaabil George Ponnuswamy Alagusundaram 《Journal of heterocyclic chemistry》2021,58(3):841-863
The N-phenylbenzo[g]indazole derivatives, 3-(4-chlorophenyl)-3,3a,4,5-tetrahydro-N-phenylbenzo[g]indazole-2-carbothioamide (4CLPBIC), 3-(4-bromophenyl)-3,3a,4,5-tetrahydro-N-phenylbenzo[g]indazole-2-carbothioamide (4BRPBIC), and 3-(3-bromophenyl)-3,3a,4,5-tetrahydro-N-phenylbenzo[g]indazole-2-carbothioamide (3BRPBIC), were synthesized by the one-pot green amalgamation of solvent-free granulating methodology procedure at room temperature. The synthesized crystals were characterized by single-crystal X-ray diffraction (SC-XRD), FT-IR, FT-Raman, NMR, and UV–Vis techniques. The molecular geometries from XRD experimental values of synthesized compounds 4CLPBIC, 4BRPBIC, and 3BRPBIC in the ground state are compared theoretically by applying the density functional theory (DFT), a method with the B3LYP/6-311G(d,p) basis set using Gaussian 09 software. The vibrational assignments of the synthesized compounds were studied based on potential energy distribution (PED) by the VEDA4 program. The scaled DFT/B3LYP/6-311G(d,p) results show the best agreement with the experimental values. Computational 1H and 13C NMR were acquired by utilizing gauge-independent atomic orbital (GIAO) procedure, and chemical shift results are in good agreement with the experimental values. A web-based theoretical investigation was performed to understand the drug-likeness and ADMET properties of the compounds. Molecular docking studies were carried out against bacterial cholesterol inhibitor block and inhibitor of lanosterol-14α-demethylase CYP51 used in the treatment of topical and systemic mycoses in fungal to understand the inhibitory activity of synthesized compounds. The synthesized molecules were also tested for antibacterial and antifungal activities. 相似文献
979.
Palladium-catalyzed carbonylation of methanol in presence of iodide promoters was investigated. Iodide bridged palladium dimeric complex, [PPh3CH3]2[Pd2I6] was isolated from the carbonylation reaction mixture and characterized using X-ray crystallography. Reaction mechanism was proposed based on IR and UV spectroscopic characterizations of catalytic species involved in the catalytic cycle. The isolated dimeric palladium species, [Pd2I6]2− underwent carbonylation to give monomeric species [PdI3CO]− at atmospheric pressure of carbon monoxide. It was also observed that PPh3 plays an important role to avoid catalyst deactivation at higher temperatures. Turnover frequency (TOF) of 1052 h−1 was achieved using Pd(OAc)2-HI-PPh3 catalyst system at 175 °C. 相似文献
980.
Naik GH Priyadarsini KI Maity DK Mohan H 《The journal of physical chemistry. A》2005,109(10):2062-2068
Reaction of one-electron oxidant (Br(2)(*-)) with tryptophol (TP) and 5-hydroxytryptophol (HTP) have been studied in aqueous solution in the pH range from 3 to 10, employing nanosecond pulse radiolysis technique and the transients detected by kinetic spectrophotometry. One-electron oxidation of TP has produced an indolyl radical that absorbs in the 300-600 nm region with radical pK(a) = 4.9 +/- 0.2, while the reaction with HTP has produced an indoloxyl radical with lambda(max) at 420 nm and radical pK(a) < 3. Hydroxyl radicals ((*)OH) react with these two compounds producing (*)OH radical adducts that undergo water elimination to give one-electron-oxidized indolyl and indoloxyl radical species, respectively. The indoloxyl radicals react with the parent compound to form dimer radicals with an average association constant of (6.7 +/- 0.4) x 10(4) M(-1). No such dimerization is observed with indolyl radical, indicating that the presence of the 5-hydroxy group markedly alters its ability to form a dimer. A possible explanation behind such a difference in reactivity has been supported with ab initio quantum chemical calculations. 相似文献