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11.
Sham M. Sondhi Monika Johar Nidhi Singhal Sunanda G. Dastidar Rakesh Shukla Ram Raghubir 《Monatshefte für Chemie / Chemical Monthly》2000,7(4):511-520
Various sulfa drugs were condensed with 4-isothiocyanato-4-methyl-2-pentanone at pH∼3–5 by refluxing in methanol to give various substituted mercaptopyrimidines. On condensation with 9-chloro-2-substituted or -unsubstituted acridines, sulfathiazole gave the corresponding condensed products. N-Ethylaminoadenosine reacted with 9-chloroacridine to the coupled product. Condensation of sulfathiazole with 9-isothiocyanato-2,4-substituted or -unsubstituted acridines afforded the corresponding condensed compounds. The structures of all synthesized compounds were confirmed by spectroscopic methods. Anticancer, antiinflammatory, and analgesic activities of all compounds were investigated. 相似文献
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Prof. Zeena S. Pillai Prof. Paola Ceroni Manja Kubeil Dr. Jan‐Martin Heldt Dr. Holger Stephan Dr. Giacomo Bergamini 《化学:亚洲杂志》2013,8(4):771-777
We have designed two novel dendrimers with cyclam cores with appended poly(amido amine) (PAMAM) dendrons, decorated at the periphery with four and eight dansyl chromophores, respectively. The photophysical properties of the dendrimers and their Nd3+ complexes have been investigated. The energy‐transfer efficiency to the lanthanide ions from these dendrimers has been studied as a function of the generation. It has been observed that an increase in the dendrimer generation as well as the number of amide units enhances the energy transfer to the lanthanide ion. 相似文献
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Rajiv K Rajni J 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1042-1049
Designing tactics were tailored and followed by synthetic and formulation methodologies to prepare 2,6,11,15-tetraoxa-9,17-diaza-1,7,10,16-(1,2)-tetrabenzenacyclooctadecaphan-8,17-diene. Spectral techniques (MS, infrared, 1H NMR, 13C NMR, electronic and EPR), physiochemical measurements (elemental analysis, molar conductance and magnetic susceptibility), electrochemistry (cyclic voltammetry) and classical mechanics (molecular modeling) were employed for structural elucidation of Co(II) and Mn(II) coordination entities having N2O4 chromophore. Comparative spectral analysis revealed legating nature of N2O4 donor macrocycle and confirmed host/guest connectivity between ligand and metal(s). Mass spectrometry (MS) determined 1:1 stoichiometry in CEs. Further electrochemical study confirmed change in oxidation and reduction patterns of CEs. Inhibiting potential (antifungal screened against Aspergillus flavus) showed enhanced antimicrobial properties of CEs as compared to ligand. Molecular modeling was employed to find out different molecular features along with their stabilization energies. 相似文献
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Zeena S. Pillai P. K. Sudeep K. George Thomas 《Research on Chemical Intermediates》2003,29(3):293-305
Photophysical properties of hemicyanine dyes (1 - 3) were investigated in solvents of varying polarity and viscosity. Hemicyanines possess relatively low fluorescence quantum yields (1%) in polar solvents. A significant increase in fluorescence quantum yield and lifetimes was observed with increase in viscosity of the solvent medium. The radiative, as well as nonradiative decay channels from the singlet-excited state were investigated by varying the viscosity of the medium. The viscosity-dependent radiationless relaxation observed in hemicyanine dyes is suggestive of a restricted rotor motion in the singlet excited state. 相似文献
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Two new, simple, reliable, and specific colour tests are described for the detection of azide. In one, the azide is heated with allyl isothiocyanate and water to form 1-allyl-2-tetrazoline-5-thione in solution; the latter gives a yellow precipitate on treatment with bismuth nitrate solution. Pyridine enhances the intensity of the colour. The allyl isothiocyanate can be produced in situ by treating allylamine with carbon disulphide, diethylamine and hydrogen peroxide. In the other test the azide is heated with carbon disulphide, water and acetone, resulting in the formation of 1,2,3,4-thiatriazoline-5-thione which gives a yellow precipitate with Cu(II) or Bi(III). Pyridine again enhances the colour. The method is applicable to 5-10 mg of soluble azides, but insoluble azides cannot be tested. CN(-), SCN(-), and other common anions do not interfere. Only S(-2) interferes by masking the colour (black CuS or Bi(2)S(3) is precipitated). NO(2)(-) in larger amounts interferes in the second test. 相似文献
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Soyoung Kim Bao-Ning Su Soedarsono Riswan Leonardus B.S. Kardono Johar J. Afriastini Judith C. Gallucci Heebyung Chai Norman R. Farnsworth Geoffrey A. Cordell Steven M. Swanson A. Douglas Kinghorn 《Tetrahedron letters》2005,46(52):9021-9024
Two benzo[b]oxepine derivatives, edulisones A (1) and B (2), were isolated from the bark of Aglaia edulis, collected in Indonesia. The relative stereochemistry of 1 was determined by single-crystal X-ray diffraction analysis. Treatment of compounds 1 and 2 with lithium hydroxide produced the same hydrolysis products, 1a and 1b, as a result of cleavage of the pyrrolidine ring to an alkylated amide mixture in each case, which demonstrated that these substances are epimeric at their 2-aminopyrrolidine moiety. 相似文献
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Streptomycin has been used to derive organic metal complexes (OMCs) after metallation with ZnCl2, CdCl2 and PbCl2 and characterized by elemental analysis, electronic and vibrational spectroscopy, 1H and 13C NMR, mass spectroscopy (time‐of‐flight MS), magnetic measurement, thermal decomposition analysis (TGA, DTA), molecular modeling and X‐ray powder diffraction. OMCs are monomeric. Crystal system, lattice parameters, unit cell, particle size and volume of crystalline OMCs have been determined using X‐ray powder diffraction pattern analysis. The geometries of complexes were optimized on the basis of molecular modeling. Kinetic parameters were computed from thermal analysis, confirming first‐order kinetics. Molecular models have been optimized by MM2 calculations. Architecture and tailoring of the rationally designed and synthesized supramolecular models having covalent bonded oxygen or other molecular contacts extended through Huckel Charge Distribution in highest occupied molecular orbit (HOMO). Antimicrobial effectiveness of OMCs has been reported. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Cross-linked 4-vinylpyridine-styrene beads (PVPS) containing various amounts of pyridine rings were synthesized and reaction with methyliodide and peroxyacetic acid gave corresponding N-methylpyridinium salts and N-oxides with more than 92% of the pyridine rings being transformed. PVPS formed stable complexes with bromine and chlorine in the ratio 1:1, and when a higher amount of halogen was used, complexes with two molecules of halogen on each pyridine were formed. Similar complexes were also formed with PVPS-N-oxides in the presence of bromine and chlorine, while the reaction of PVPS-hydrohalide with bromine and chlorine resulted in hydrobromide perbromide and hydrochloride perchloride resins. The chemical activity of halo-substituted resins was tested in the reaction with 1,1-diphenylethylene. Chi or o-substituted resins are very stable, while bromo-substituted beads gave bromoalkene, dibromide, and alkoxybromide, depending on the structure of the reagent, solvent, and reaction temperature. 相似文献