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921.
Maxim E. Kukushkin Dmitriy A. Skvortsov Marina A. Kalinina Viktor A. Tafeenko Vladimir V. Burmistrov Gennady M. Butov 《Phosphorus, sulfur, and silicon and the related elements》2020,195(7):544-555
AbstractAn effective and highly regio- and diastereoselective one-pot synthesis of two types of dispiro heterocyclic systems (2-thioxodispiro[imidazolidine-4,3′-pyrrolidine-2′,3″-indoline]-2″,5-diones and 2-thioxodispiro[imidazolidine-4,3′-pyrrolidine-4′,3″-indoline]-2″,5-diones) comprising pyrrolidinyl-oxindole, thiohydantoin and adamantane moieties has been developed based on a 1,3-dipolar cycloaddition of azomethine ylides, generated from isatin and sarcosine or formaldehyde and sarcosine, to adamantane-containing electron-deficient alkenes. Several molecules have demonstrated a considerable cytotoxicity against A549, HEK293T, MCF7 and VA13 cancer cell lines. The possible mechanism of anticancer activity of the synthesized compounds based on literature data may be the inhibition of p53/MDM2 interaction; however, we did not observe significant p53 activation using a reporter construction in A549 cell line in the relevant concentration range. 相似文献
922.
Trevor A. Shear Fuding Lin Lev N. Zakharov Darren W. Johnson 《Angewandte Chemie (International ed. in English)》2020,59(4):1496-1500
Cyclophanes are a venerable class of macrocyclic and cage compounds that often contain unusual conformations, high strain, and unusual properties. However, synthesis of complex, functional derivatives remains difficult due to low functional group tolerance, high dilution, extreme reaction conditions, and sometimes low yields using traditional stepwise synthetic methods. “Design of experiments” (DOE) is a method employed for the optimization of reaction conditions, and we showcase this approach to generate a dramatic increase in the yield of specific targets from two different self‐assembling systems. These examples demonstrate that DOE provides an additional tool in tuning self‐assembling, dynamic covalent systems. 相似文献
923.
Sergey V. Ovsyannikov Maxim Bykov Sergey A. Medvedev Pavel G. Naumov Anton Jesche Alexander A. Tsirlin Elena Bykova Irina Chuvashova Alexander E. Karkin Vadim Dyadkin Dmitry Chernyshov Leonid S. Dubrovinsky 《Angewandte Chemie (International ed. in English)》2020,59(14):5632-5636
Functional oxides whose physicochemical properties may be reversibly changed at standard conditions are potential candidates for the use in next‐generation nanoelectronic devices. To date, vanadium dioxide (VO2) is the only known simple transition‐metal oxide that demonstrates a near‐room‐temperature metal–insulator transition that may be used in such appliances. In this work, we synthesized and investigated the crystals of a novel mixed‐valent iron oxide with an unconventional Fe5O6 stoichiometry. Near 275 K, Fe5O6 undergoes a Verwey‐type charge‐ordering transition that is concurrent with a dimerization in the iron chains and a following formation of new Fe?Fe chemical bonds. This unique feature highlights Fe5O6 as a promising candidate for the use in innovative applications. We established that the minimal Fe?Fe distance in the octahedral chains is a key parameter that determines the type and temperature of charge ordering. This model provides new insights into charge‐ordering phenomena in transition‐metal oxides in general. 相似文献
924.
V. L. Bukhovets A. E. Gorodetsky R. Kh. Zalavutdinov A. P. Zakharov 《High Energy Chemistry》2013,47(2):67-72
The effect of addition of nitrogen or ammonia in an amount equal to the flow of methane entering as a 7: 1 H2/CH4 mixture into a hollow-cathode dc glow flow discharge on the rate of deposition/erosion of amorphous hydrocarbon (a-C:H) films at 300 K has been studied. The introduction N2 or NH3 into the mixture facilitates the transition from deposition to erosion of a-C(N):H films in the hollow cathode, but has a little effect on the growth rate of a-C(N):H films in the positive column and in the afterglow of the discharge. It has been suggested that the changes in the a-C:H film deposition/erosion rate are due to the formation of hydrogen cyanide, mainly, on the hollow-cathode surface. 相似文献
925.
Mathematical Notes - 相似文献
926.
Darya A. Kuznetsova Dinar R. Gabdrakhmanov Denis M. Kuznetsov Svetlana S. Lukashenko Valery M. Zakharov Anastasiia S. Sapunova Syumbelya K. Amerhanova Anna P. Lyubina Alexandra D. Voloshina Diana V. Salakhieva Lucia Ya. Zakharova 《Molecules (Basel, Switzerland)》2021,26(8)
The solution behavior and physicochemical characteristics of polymer–colloid complexes based on cationic imidazolium amphiphile with a dodecyl tail (IA-12) and polyacrylic acid (PAA) or DNA decamer (oligonucleotide) were evaluated using tensiometry, conductometry, dynamic and electrophoretic light scattering and fluorescent spectroscopy and microscopy. It has been established that PAA addition to the surfactant system resulted in a ca. 200-fold decrease in the aggregation threshold of IA-12, with the hydrodynamic diameter of complexes ranging within 100–150 nm. Electrostatic forces are assumed to be the main driving force in the formation of IA-12/PAA complexes. Factors influencing the efficacy of the complexation of IA-12 with oligonucleotide were determined. The nonconventional mode of binding with the involvement of hydrophobic interactions and the intercalation mechanism is probably responsible for the IA-12/oligonucleotide complexation, and a minor contribution of electrostatic forces occurred. The latter was supported by zeta potential measurements and the gel electrophoresis technique, which demonstrated the low degree of charge neutralization of the complexes. Importantly, cellular uptake of the IA-12/oligonucleotide complex was confirmed by fluorescence microscopy and flow cytometry data on the example of M-HeLa cells. While single IA-12 samples exhibit roughly similar cytotoxicity, IA-12–oligonucleotide complexes show a selective effect toward M-HeLa cells (IC50 1.1 µM) compared to Chang liver cells (IC50 23.1 µM). 相似文献
927.
Sergey Tsymbal Ge Li Nikol Agadzhanian Yuhao Sun Jiazhennan Zhang Marina Dukhinova Viacheslav Fedorov Maxim Shevtsov 《Molecules (Basel, Switzerland)》2022,27(20)
Treatment of drug-resistant forms of cancer requires consideration of their hallmark features, such as abnormal cell death mechanisms or mutations in drug-responding molecular pathways. Malignant cells differ from their normal counterparts in numerous aspects, including copper metabolism. Intracellular copper levels are elevated in various cancer types, and this phenomenon could be employed for the development of novel oncotherapeutic approaches. Copper maintains the cell oxidation levels, regulates the protein activity and metabolism, and is involved in inflammation. Various copper-based compounds, such as nanoparticles or metal-based organic complexes, show specific activity against cancer cells according to preclinical studies. Herein, we summarize the major principles of copper metabolism in cancer cells and its potential in cancer theranostics. 相似文献
928.
P. I. Zakharov P. B. Terent'ev G. K. Nikonov L. G. Avramenko A. A. Azizov A. I. Ban'kovskii 《Chemistry of Natural Compounds》1976,10(5):586-588
Summary From a methanolic extract of the roots ofPrangos biebersteinii Karjag., in addition to substances found previously, two other components — (I) and (II) — of the coumarin series have been isolated.The results of a study of their IR, NMR, and mass spectra, and also their chemical properties have enabled (I) to be identified as the known coumarin umbelliferone and the structure of 5-(1,2-dihydroxy-isopropyl)-4,5-dihydrofuro-2,3:7,6-coumarin to be proposed for (II), which has been named prandiol.Leningrad Sanitary-Hygenic Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 574–577, September–October, 1974. 相似文献
929.
Zakharov BA Kolesov BA Boldyreva EV 《Physical chemistry chemical physics : PCCP》2011,13(28):13106-13116
Predicting behaviour of hydrogen bonds with varying temperature, in particular-correlating donor-acceptor distances in the O-H···O hydrogen bonds with the frequencies of O-H stretching vibrations is important for understanding dynamics of biomolecules and phase transitions in crystals. A commonly used correlation suggested earlier in the literature is based on statistical analysis of different compounds [A. Novak, Structure and Bonding, 1974, 18, 177; K. Nakamoto, M. Margoshes, R. E. Rundle, J. Am. Chem. Soc., 1955, 77, 6480]. The present study is a rare example when correlations between geometry and energy parameters have been found for selected individual hydrogen bonds in the same crystalline compound at multiple temperatures. The properties of several types of O-H···O hydrogen bonds in bis(DL-serinium) oxalate dihydrate and DL-alaninium semi-oxalate monohydrate have been studied by a combination of variable-temperature single-crystal X-ray diffraction and polarized Raman spectroscopy. The changes in the hydrogen bonds geometry could be compared with the changes of the corresponding spectral modes. The correlation suggested by Novak is roughly followed, better for medium and weak, than for short hydrogen bonds. Fine details of spectral changes differ for individual bonds. The way how H-bonds are affected by cooling depends on their environment in the crystal structure. Short O-H···O hydrogen bonds in bis(DL-serinium) oxalate dihydrate expand or remain almost unchanged on cooling, whereas in DL-alaninium semi-oxalate monohydrate all strong H-bonds are compressed under these conditions. The distortion of individual hydrogen bonds on temperature variations is correlated with the anisotropy of lattice strain. 相似文献
930.
G. A. Nesterov V. A. Zakharov Yu. I. Yermakov K. -H. Thiele M. Schlegel H. Drevs 《Reaction Kinetics and Catalysis Letters》1980,13(4):401-406
Composition and catalytic properties in ethylene polymerization of supported systems prepared via the interaction of Ti(CH2C6H5)3X (X=F, Cl, Br) and Zr(CH2C6H5)2Cl2 complexes with silica and alumina have been studied. Halide addition to benzyl complexes decreases the polymer molecular mass.
, Ti(CH2C6H5)3X (X=F, Cl, Br) Zr(CH2C6H5)2Cl2 SiO2 Al2O3. , .相似文献