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101.
The synthesis of (3S,4R,5R)-3-(2-hydroxyethyl)piperidine-3,4,5-triol 10 has been described from d-glucose. The base promoted cyclization for the construction of the piperdine framework is the key step of the synthesis. 相似文献
102.
Sagar Sharma Rajesh S. Baligar Harkesh B. Singh Prof. Ray J. Butcher Prof. 《Angewandte Chemie (International ed. in English)》2009,48(11):1987-1990
All wrapped up : The reaction of a 22‐membered macrocycle derived from bis(o‐formylphenyl)mercury and 1,2‐phenylenediamine with palladium(II) results in cleavage of the macrocycle and concomitant formation of a trimetallic complex (see picture; phenyl rings truncated for clarity). The nature of the HgII???PdII???HgII interaction was investigated by theoretical studies.
103.
Rahul R. Kolhapurkar Preeti K. Patil Dilip H. Dagade Kesharsingh J. Patil 《Journal of solution chemistry》2006,35(10):1357-1376
Experimental measurements of the speed of sound, density and osmotic vapour pressure are reported for binary 18-Crown-6 (18C6) + CH3OH, KBr + CH3OH and ternary KBr + 18C6 + CH3OH solutions at 298.15 K. The density and compressibility data were processed to obtain the apparent molar volume (ø V ) and apparent molar isentropic compressibility ( $\phi _{K_S } Experimental measurements of the speed of sound, density and osmotic vapour pressure are reported for binary 18-Crown-6 (18C6) + CH3OH, KBr + CH3OH and ternary KBr + 18C6 + CH3OH solutions at 298.15 K. The density and compressibility data were processed to obtain the apparent molar volume (?
V
) and apparent molar isentropic compressibility () of the solutes in methanol. Expansivity data were obtained for the 18C6 + CH3OH system from density data at different temperatures and were used for calculation of the isothermal compressibility values at 298.15 K. The isothermal compressibility and expansivity data are further used to obtain the apparent molar isothermal compressibility () and apparent molar expansivity (?
E
) of 18C6 in methanolic solutions and as well as the energy-volume coefficient parameter (∂ U/∂ V)
T
in methanol solutions. The volume and compressibility changes due to complexation of KBr with 18C6 are obtained at infinite dilution for ?
V
and ?
K
. The results are compared with the similar data obtained by us previously for aqueous and CCl4 solutions. The osmotic coefficient data were used to calculate activities and activity coefficients of each component at 298.15 K as a function of the concentration of binary and ternary methanolic solutions containing KBr and 18C6. The activity and activity coefficient data are used to evaluate the pair and triplet interaction parameters by making appropriate use of the McMillan-Meyer theory of solutions. The calculation of the thermodynamic equilibrium constant (K) is made using the pair interaction parameter, g
NE
(non-electrolyte – electrolyte pair interaction), for the complexation equilibria. The nature of interactions present in the CH3OH solutions is discussed. 相似文献
104.
Preeti Joshi Harish C. Joshi Sunil Kumar Sanghi Subir Kundu 《Mikrochimica acta》2010,169(3-4):383-388
An amperometric biosensor for dopamine is described. It is based on the enzyme monoamine oxidase immobilized on a glutaraldehyde-activated eggshell membrane that was deposited on a glassy carbon electrode. The Michaelis-Menten constant (Km) is 0.087 mM. Optimum pH and temperature conditions were obtained at pH 7.0 and 37 °C, respectively. The sensor showed a detection limit of 20 μM, a linear range from 50 μM to 250 μM, and a storage stability of ~25 days. In order to further improve the performance, a Nafion coating was applied on the electrode surface which gave favorable results with respect to shelf life of the enzyme (~40 days), the limit of detection, and the selectivity over ascorbic acid and uric acid. 相似文献
105.
106.
107.
The diazirine 1 , upon thermolysis or photolysis in either acetone or cyclohexanone, at different concentrations, yield the spiro epoxides 2 and 3 , and 4 and 5 , respectively (Scheme 1). Yield of 2 and 3 depended both on the temperature and the concentration, and correlated inversely with the yield of the major by-product, the enol-derived glycoside 6 . Other by-product were the benzyloxglycal 7 and the lactone azines 8 . ZnCl2-Promoted methanolysis of 2 under mild condition yielded mixture of the uloside 9 and 10 (1.2:1); similarly, 4 yielded 11 and 12 (1.8:1; Scheme 2). More strongly acidic conditions converted 11 into 12 , evidencing that ZnCl2-promoted methanolysis proceeds under kinetic control, which is rationalized. The diazirine 13 , upon thermolysis of Photolysis in either acetone of cyclohexanone, yielded the α-D -configurated spiro epoxides 14 and 16 , and the α-D -configurated dihydrooxazoles 15 and 17 , respectively (Scheme 3), which are either formed by ring-opening of ß-D -epoxides, by competitive interception of the initially formed, hypothetical addition products of the intermediate carbene to the ketones. The glycosylidene carbenes, derived from 1 or 13 are not very reactive towards ketones, yields are good only when sterically unhindered ketones are used in large excess. 相似文献
108.
A. D. Sagar M. M. Salunkhe P. P. Wadgaonkar B. D. Sarawade S. S. Mahajan 《Journal of polymer science. Part A, Polymer chemistry》1997,35(6):1077-1085
Ten new aromatic polyamides containing s-triazine rings in the main chain were synthesized by the low temperature interfacial polycondensation technique involving the reactions of each of the two s-triazine containing diacylchlorides, viz., 2,4-bis (4-chlorocarbonylphenoxy)-6-methoxy-s-triazine and 2,4-bis(3-chlorocarbonylphenoxy)-6-methoxy-s-triazine, with five aromatic diamines namely, 4,4′-bis(4-aminophenoxy)diphenyl sulfone, 4,4′-bis(3-aminophenoxy)diphenyl sulfone, 2,2-bis[4(4-aminophenoxy) phenyl] propane, 1,4 bis (4-amino-phenoxy) benzene, and 1,3-bis (4-aminophenoxy)benzene. The resulting polyamides were characterized by viscosity measurements, IR and 1H-NMR spectroscopy, solubility tests, x-ray diffraction, and thermogravimetry. The polyamides had inherent viscosities in the range of 0.16–1.06 dL/g in N,N-dimethylacetamide at 30°C. Most of the s-triazine containing polyamides dissolved readily at room temperature in polar solvents. Except for the polyamide PA-2, the polyamides did not lose weight below 350°C under a nitrogen atmosphere. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1077–1085, 1997 相似文献
109.
Madhuchandra Kenchegowda Mohamed Rahamathulla Umme Hani Mohammed Y. Begum Sagar Guruswamy Riyaz Ali M. Osmani Mysore P. Gowrav Sultan Alshehri Mohammed M. Ghoneim Areej Alshlowi Devegowda V. Gowda 《Molecules (Basel, Switzerland)》2022,27(1)
Cancer is a group of disorders characterized by uncontrolled cell growth that affects around 11 million people each year globally. Nanocarrier-based systems are extensively used in cancer imaging, diagnostics as well as therapeutics; owing to their promising features and potential to augment therapeutic efficacy. The focal point of research remains to develop new-fangled smart nanocarriers that can selectively respond to cancer-specific conditions and deliver medications to target cells efficiently. Nanocarriers deliver loaded therapeutic cargos to the tumour site either in a passive or active mode, with the least drug elimination from the drug delivery systems. This review chiefly focuses on current advances allied to smart nanocarriers such as dendrimers, liposomes, mesoporous silica nanoparticles, quantum dots, micelles, superparamagnetic iron-oxide nanoparticles, gold nanoparticles and carbon nanotubes, to list a few. Exhaustive discussion on crucial topics like drug targeting, surface decorated smart-nanocarriers and stimuli-responsive cancer nanotherapeutics responding to temperature, enzyme, pH and redox stimuli have been covered. 相似文献
110.
Mazaahir Kidwai Preeti Misra Bhavesh Dave Kumar R. Bhushan Rajendra K. Saxena Meena Singh 《Monatshefte für Chemie / Chemical Monthly》2000,131(11):1207-1212
Summary. A novel synthesis of 6-fluoro-7-(5-aryl-1,3,4-thiadiazol/oxadiazol-2-yl-sulfanyl)-4-quinolone-3-carboxylic acids from 7-chloro-6-fluoro-4-quinolone-3-carboxylic
acid and 5-substituted 1,3,4-thiadiazoles/oxadiazoles on basic alumina under microwave activation is described. All compounds
were screened for their in vitro antibacterial activity against B. lichenformis, 2689, K. aerogens 2281, S. typhimurium 2501, E. herbicola 2491, and P. vulgaris 2027 and found to possess activities comparable to that of the standard drug norfloxacin.
Received May 2, 2000. Accepted (revised) June 13, 2000 相似文献