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Supramolecular Interactions of Nonsteroidal Anti‐inflammatory Drug in Nanochannels of Molecular Containers: A Spectroscopic,Thermogravimetric and Microscopic Investigation 下载免费PDF全文
Banibrata Maity Aninda Chatterjee Sayeed Ashique Ahmed Dr. Debabrata Seth 《Chemphyschem》2014,15(16):3502-3514
Supramolecular host–guest complexation between the nonsteroidal anti‐inflammatory drug indomethacin (IMC) and molecular containers were investigated. The weakly fluorescent drug molecule becomes highly fluorescent on complexation with different molecular containers, and time‐resolved fluorescence emission spectroscopy reveals that the lifetime components of IMC significantly increase in the presence of molecular containers, compared with the lifetimes in neat water. The respective solid host–guest complexes were synthesised and characterised by Fourier transform infrared and 1H nuclear magnetic resonance spectroscopic analysis. Microscopy techniques were used to analyse modifications of the surface morphology, owing to the formation of supramolecular complexes. The effect of the molecular container on the optical properties of IMC has also been investigated to determine the effect of nanochannels of different size and structure. 相似文献
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Neil Vasdev Raman Chirakal Rezwan Ashique Gary J. Schrobilgen Karen Gulenchyn 《Journal of fluorine chemistry》2003,121(1):9-14
The detection of 3-nitro-l-tyrosine has been used as a biomarker of “reactive nitrogen species” in biological matrices and has been an ongoing challenge in analytical chemistry. In this work, fluorine-18 labelled 5-fluoro-3-nitro-l-tyrosine (FNT) was synthesized as a potential radiotracer to probe the biological fate of 3-nitro-l-tyrosine. The synthesis of []FNT was carried out by reaction of []3-fluoro-l-tyrosine with NaNO3 in TFA solvent for 5 min at 4 °C. The radiochemical yield (RCY) of []FNT was 96±2% and []3-fluoro-l-tyrosine, was 29±1%, relative to []3-fluoro-l-tyrosine and []F2, respectively. The syntheses of []FNT were also accomplished by direct fluorination of 3-nitro-l-tyrosine with []F2 and by nitration of l-tyrosine with NaNO3, followed by fluorination, in TFA (4 °C) or anhydrous HF (−65 °C) solvent. The latter two synthetic routes produced []FNT in 13.5±1.5% RCY, within 1 h. Products were characterized by use of , and NMR spectroscopy and mass spectrometry. 相似文献
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Sepay Nayim Sepay Nadir Al Hoque Ashique Mondal Rina Halder Umesh Chandra Muddassir Mohd. 《Structural chemistry》2020,31(5):1831-1840
Structural Chemistry - Novel coronavirus, 2019-nCoV is a danger to the world and is spreading rapidly. Very little structural information about 2019-nCoV make this situation more difficult for drug... 相似文献
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Photophysics and Rotational Dynamics of a Hydrophilic Molecule in a Room Temperature Ionic Liquid 下载免费PDF全文
Aninda Chatterjee Banibrata Maity Sayeed Ashique Ahmed Debabrata Seth 《Photochemistry and photobiology》2015,91(5):1056-1063
We have studied the photophysics and rotational diffusion of hydrophilic solute 7‐(N, N′‐diethylamino)coumarin‐3‐carboxylic acid (7‐DCCA) in a room temperature ionic liquid methyltrioctylammonium bis(trifluoromethylsulfonyl) imide ([N1888][NTf2]). Comparison of activation energies of viscous flow and nonradiative decay shows that the photophysical properties of 7‐DCCA are not guided by the bulk viscosity of the medium but are dependent on the specific solute solvent interaction and structural heterogeneity of the medium. The rotational relaxation behaviour of 7‐DCCA in [N1888][NTf2] shows significant deviation from the Stokes Einstein Debye hydrodynamic model of rotational diffusion. This is indicative of the influence of specific solute solvent interaction on the rotational relaxation behaviour of 7‐DCCA. Comparison of activation energy of rotational relaxation with activation energy of viscous flow clearly reinforces our assumption that the structural heterogeneity of the medium and specific solute solvent interaction plays a dominant role on the rotational diffusion instead of bulk viscosity. 相似文献
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Babak Behnam Azad Rezwan Ashique Gary J. Schrobilgen 《Journal of fluorine chemistry》2008,129(1):22-27
Fluorine-18 labeled aromatic amino acids are routinely used as tracers in positron emission tomography (PET) to study in vivo metabolic processes. The most versatile method for the production of such radiotracers is electrophilic fluorination of the aromatic amino acid with [18F]F2, which is most commonly produced by the gas-phase nuclear reaction 18O(p, n)18F. Although [18F]F2 is the major product, considerable amounts of [18F]OF2 (up to 20%) are also produced. Electrophilic fluorination reactions of l-phenylalanine, 3-nitro-l-tyrosine, 4-nitro-dl-phenylalanine, 3,4-dihydroxyphenyl-l-alanine (l-DOPA), 3-O-methyl-l-DOPA, 3,4-dimethoxy-l-phenylalanine, p-tyrosine and o-tyrosine in H2O and of m-tyrosine in anhydrous HF (aHF), CF3SO3H, CF3COOH, CH3COOH, HCOOH and H2O using OF2 were investigated. Although F2 is an efficient fluorinating agent in aHF, electrophilic fluorination reactions using OF2 were shown to be most efficient in less acidic media such as H2O. In addition, and contrary to reports that OF2 and F2 have similar reactivities, m-tyrosine was the only aromatic system studied that was fluorinated by OF2 and this was optimum in H2O for the fluorinated m-tyrosine isomers (total yield, 4.35 ± 0.04%). The presence of [18F]OF2 byproduct has no significant impact on the fluorination of aromatic amino acids investigated in this study and the subsequent production of their corresponding 18F-labeled radiotracers for patient use. 相似文献
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