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排序方式: 共有316条查询结果,搜索用时 15 毫秒
1.
Sakhautdinova G. F. Sakhautdinov I. M. Mustafin A. G. Yunusov M. S. 《Chemistry of Natural Compounds》2022,58(1):185-186
Chemistry of Natural Compounds - 相似文献
2.
S. M. Sergazina B. K. Kasenov E. S. Mustafin Sh. B. Kasenova Zh. I. Sagintaeva R. Sh. Erkasov 《Russian Journal of Applied Chemistry》2006,79(8):1225-1229
Ferrites with the composition GdMIIFe2O5.5 (MII = Mg, Ca, Sr) were synthesized from the corresponding oxides by the solid-phase method. The temperature dependence of the specific heat was studied by dynamic calorimetry in the temperature range 298.15 673 K. Equations describing this temperature dependence were derived. The temperature dependences of the thermodynamic functions were calculated. 相似文献
3.
D. I. D'yachenko A. G. Mustafin V. V. Shereshovets N. N. Kabal'nova V. P. Kazakov I. B. Abdrakhmanov G. A. Tolstikov 《Russian Chemical Bulletin》1998,47(8):1611-1612
An unusual direction of the reaction of 2-(cyclopent-2-enyl)aniline hydrochloride with dimethyldioxirane was found: the formation
of two isomeric products,viz., 3- and 6-chloro-2-(cyclopent-2-enyl)anilines, was observed.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1654–1655, August, 1998. 相似文献
4.
B. A. Arbuzov A. M. Polozov N. A. Polezhaeva A. Kh. Mustafin Ya. A. Levin É. I. Gol'dfarb 《Russian Chemical Bulletin》1989,38(3):651-653
Conclusions The direct photolysis of diphenyldiazomethane in dimethyl thiophosphite gave the product of P-H insertion. The thermal reaction leads to the N-dimethoxythiophosphorylhydrazone of benzophenone and O,O-dimethyl S-(diphenylmethyl) thiophosphate. Carbenoid P-H insertion occurred in the thermocatalytic decomposition.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 726–727, March, 1989. 相似文献
5.
Protein kinases are important enzymes controlling the majority of cellular signaling events via a transfer of the gamma-phosphate of ATP to a target protein. Even after many years of study, the mechanism of this reaction is still poorly understood. Among many factors that may be responsible for the 1011-fold rate enhancement due to this enzyme, the role of the conserved aspartate (Asp166) has been given special consideration. While the essential presence of Asp166 has been established by mutational studies, its function is still debated. The general base catalyst role assigned to Asp166 on the basis of its position in the active site has been brought into question by the pH dependence of the reaction rate, isotope measurements, and pre-steady-state kinetics. Recent semiempirical calculations have added to the controversy surrounding the role of Asp166 in the catalytic mechanism. No major role for Asp166 has been found in these calculations, which have predicted the reaction process consisting of an early transfer of a substrate proton onto the phosphate group. These conclusions were inconsistent with experimental observations. To address these differences between experimental results and theory with a more reliable computational approach and to provide a theoretical platform for understanding catalysis in this important enzyme family, we have carried out first-principles structural and dynamical calculations of the reaction process in cAPK kinase. To preserve the essential features of the reaction, representations of all of the key conserved residues (82 atoms) were included in the calculation. The structural calculations were performed using the local basis density functional (DFT) approach with both hybrid B3LYP and PBE96 generalized gradient approximations. This kind of calculation has been shown to yield highly accurate structural information for a large number of systems. The optimized reactant state structure is in good agreement with X-ray data. In contrast to semiempirical methods, the lowest energy product state places the substrate proton on Asp166. First-principles molecular dynamics simulations provide additional support for the stability of this product state. The latter also demonstrate that the proton transfer to Asp166 occurs at a point in the reaction where bond cleavage at the PO bridging position is already advanced. This mechanism is further supported by the calculated structure of the transition state in which the substrate hydroxyl group is largely intact. A metaphoshate-like structure is present in the transition state, which is consistent with the X-ray structures of transition state mimics. On the basis of the calculated structure of the transition state, it is estimated to be 85% dissociative. Our analysis also indicates an increase in the hydrogen bond strength between Asp166 and substrate hydroxyl and a small decrease in the bond strength of the latter in the transition state. In summary, our calculations demonstrate the importance of Asp166 in the enzymatic mechanism as a proton acceptor. However, the proton abstraction from the substrate occurs late in the reaction process. Thus, in the catalytic mechanism of cAPK protein kinase, Asp166 plays a role of a "proton trap" that locks the transferred phosphoryl group to the substrate. These results resolve prior inconsistencies between theory and experiment and bring new understanding of the role of Asp166 in the protein kinase catalytic mechanism. 相似文献
6.
I. R. Bazhenova E. A. Glukhov A. G. Mustafin Yu. B. Monakov 《Russian Journal of Applied Chemistry》2012,85(6):974-979
The stereoregulating heterogeneity manifested in butadiene polymerization by active sites of the titanium catalytic system formed “separately” in combination with organoaluminum ligands was examined. 相似文献
7.
Inna P. Tsypysheva Alexander N. Lobov Alena V. Kovalskaya Valentina I. Vinogradova Kyrill Yu. Suponitsky Sergey L. Khursan Marat S. Yunusov 《Tetrahedron: Asymmetry》2013,24(20):1318-1323
The Diels–Alder adducts of the quinolizidine alkaloids N-methylcytisine, (?)-leontidine, and (?)-thermopsine with N-phenylmaleimide have been synthesized. The structures and absolute configurations of the new asymmetric centers of the products were determined by NMR spectroscopy experiments, QC-calculations, and X-ray data. 相似文献
8.
I. M. Sakhautdinov G. F. Sakhautdinova A. G. Mustafin 《Russian Journal of General Chemistry》2020,90(2):244-248
Bromo- and chloromethyl ketones based on N-phthalyl-substituted amino acids have been synthesized via the Arndt–Eistert reaction. The products [2+1] cycloaddition to the fullerene scaffold has afforded the monoadducts of fullerene C60. 相似文献
9.
Yulya N. Biglova Rauilya N. Malikova Svetlana F. Petrova Sergey P. Ivanov Ilshat M. Sakhautdinov Akhat G. Mustafin 《国际化学动力学杂志》2019,51(5):311-320
The kinetics of nucleophilic fullerene cyclopropanation by halomethyl ketones with a diterpene fragment has been studied by the Bingel method, and the influence of the biologically active cyclopropanating agent on the process has been estimated. It has been revealed that favorable conditions for carrying out the reaction result in maximum monofunctionalized methanofullerenes formation with the maximum yield. 相似文献
10.
Russian Chemical Bulletin - The previously obtained experimental and quantum chemical data on the composition, structure, stability, and thermodynamic properties of complexes of uracil and a series... 相似文献