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991.
V. P. Shchipanov I. Ya. Postovskii E. I. Rysakova 《Chemistry of Heterocyclic Compounds》1968,4(2):161-163
In order to study the connection between the structure of sulfanilamides and their antibacterial action, sulfanilamide derivatives of 1- and 2-methyl-5-aminotetrazoles and of 1,3-dimethyl-5-iminotetrazole have been synthesized. A study of their IR spectra has shown that 1-methyl-5-sulfanilimidotetrazole has the imide structure in the crystalline state and 2-methyl-5-sulfanilamidotetrazole the amide structure. The sulfanilamide derivatives of 1- and 2-methyl-5-aminotetrazoles possess a considerable antibacterial activity, while 1, 3-dimethyl-5-sulfanilimidotetrazole is inactive. 相似文献
992.
993.
QinZHAO RuoYUAN ChangLiMO YaQinCHAI XiaZHONG 《中国化学快报》2004,15(2):208-211
Naphthol green B was used, for the first time, as a new mediator in an amperometric glucose biosensor. It is a good mediator, promoting electron transfer from glucose oxidase to graphite electrode. The biosensor shows high sensitivity to glucose at low potential with response time of 30 seconds. The linear range is from 1.5 to 18μmol/L glucose with detection limit of 0.5μmol/L glucose. 相似文献
994.
995.
L. V. Fedorova L. G. Kovalenko N. Ya. Krasnobrizhii 《Chemistry of Natural Compounds》1976,11(1):39-41
Summary The synthesis of the methyl ester of the hexapeptide N-Cbo-glycyl-L-valyl-L-seryl-L-prolyl-N-tos-L-lysyl-L-leucine, not described in the literature, has been affected.T. G. Shevchenko Kiev State University. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 41–43, January–February, 1975. 相似文献
996.
It was found that a binuclear complex of nickel(II), unlike its mononuclear analog, undergoes reversible dehydration/hydration in the solid state accompanied by a change in color. The probable cause of this is breaking/formation of a specific network of hydrogen bonds in the crystal lattice of the binuclear compound.Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 31, No. 2, pp. 110–113, March–April, 1995.The authors are grateful to N. I. Yashin for carrying out the thermoanalytical measurements.This work is part of the program of the International Science Fund (Grant UBG 000) and was also financially supported by the State Fund for Fundamental Research of the Ukrainian State Committee on Science and Technology (Project 3.3/52). 相似文献
997.
Terbium-sensitized luminescence determination of levofloxacin in tablets and human urine and serum 总被引:3,自引:0,他引:3
A selective and sensitive luminescence method for the determination of levofloxacin is described. The method is based in the luminescence signal from a terbium(III)-levofloxacin complex, in a micellar solution of sodium dodecyl sulfate (SDS), using a chemical deoxygenation agent (Na2SO3). The method allows the determination of 8-600 ng mL-1 of levofloxacin in 10 mM SDS solution containing 0.04 M acetic acid-sodium acetate buffer (pH 6) and 7.5 mM Na2SO3 with lambda exc = 292 nm and lambda em = 546 nm. The luminescence method was applied to the determination of the levofloxacin in a Spanish commercialized pharmaceutical formulation Tavanic (Hoechst Marion Roussel). Good concordance was found between the nominal and experimental values (500 and 488 mg, respectively), with a relative standard deviation (RSD) of 0.6%. The proposed method was shown to be 100-fold more sensitive than the spectrophotometric method, and nearly 2-fold more sensitive than the fluorescence method. The method was also applied to levofloxacin determination in human serum (by external calibration method) and urine (by standard additions method), spiked at levels found after drug administration at normal clinical doses. Average recoveries found were 90.1 (RSD 1%) and 102 (RSD 1.9%), respectively. 相似文献
998.
Greig MJ Bolaños B Quenzer T Bylund JM 《Rapid communications in mass spectrometry : RCM》2003,17(24):2763-2768
Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) was coupled with atmospheric pressure photoionization (APPI) for the first time and used for the analysis of several corticosteroids.1 The analytes showed excellent response using APPI when compared with both electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI). APPI has the advantage of requiring less heat for desolvation, resulting in less thermal degradation of the analytes and higher signal-to-noise than APCI. In terms of ultimate sensitivity, APPI is more efficient than either ESI or APCI for the analysis of corticosteroids. With some compounds, the high-resolution capability of FTICRMS was necessary to obtain an accurate mass due to contributions of the M(+.) (13)C isotope in the [M+H](+) ion peak. 相似文献
999.
Fondo M García-Deibe AM Corbella M Ruiz E Tercero J Sanmartín J Bermejo MR 《Inorganic chemistry》2005,44(14):5011-5020
The new tetranuclear carbonate complex [Cu2L)2(CO3)] x 8H2O (1 x 8H2O) (H3L = (2-(2-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) has been obtained by two different synthetic routes and fully characterized. Recrystallization of 1 x 8H2O in methanol yields single crystals of {[(Cu2L)2(CO3)]}2 x 12H2O (1 x 6H2O), suitable for X-ray diffraction studies. The crystal structure of 1 x 6H2O shows two crystallographically different tetranuclear molecules in the asymmetric unit, 1a and 1b. Both molecules can be understood as self-assembled from two dinuclear [Cu2L]+ cations, joined by a mu4-eta(2):eta(1):eta(1) carbonate ligand. The copper atoms of each crystallographically different [(Cu2L)2(CO3)] molecule present miscellaneous coordination polyhedra: in both 1a and 1b, two metal centers are in square pyramidal environments, one displays a square planar chromophore and the other one has a geometry that can be considered as an intermediate between square pyramid and trigonal bipyramid. Magnetic studies reveal net intramolecular ferromagnetic coupling between the metal atoms. Density functional calculations allow the assignment of the different magnetic coupling constants and explain the unexpected ferromagnetic behavior, because of the presence of an unusual NCN bridging moiety and countercomplementarity of the phenoxo (or carbonate) and NCN bridges. 相似文献
1000.
Yu. A. Titov N. S. Slobodyanik Ya. A. Kraevskaya N. N. Belyavina V. Ya. Markiv 《Theoretical and Experimental Chemistry》2007,43(6):380-384
The synthesis of three-layered titanates BaLn2Ti3O10 (Ln = La, Nd, Sm) in systems with coprecipitated hydroxocarbonates was studied. It was established that they are formed through
an intermediate phase with a defective perovskite structure followed by its transformation into the three-layered structure
by the ordering of vacancies and rare-earth element and barium atoms and subdivision into three-layered blocks.
__________
Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 6, pp. 349–353, November–December, 2007. 相似文献