排序方式: 共有102条查询结果,搜索用时 15 毫秒
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Kseniya Maryunina Gleb Letyagin Galina Romanenko Artem Bogomyakov Vitaly Morozov Sergey Tumanov Sergey Veber Matvey Fedin Evgeniya Saverina Mikhail Syroeshkin Mikhail Egorov Victor Ovcharenko 《Molecules (Basel, Switzerland)》2022,27(21)
The 2-imidazoline nitroxide derivatives of cymantrene—2-(η5-cyclopentadienyl)tricarbonylmanganese(I)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (NNMn) and 2-(η5-cyclopentadienyl)tricarbonylmanganese(I)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl (INMn) were synthesized. It was shown that NNMn and INMn exhibit a sufficiently high kinetic stability both in solids and in solutions under normal conditions. Their structural characteristics, magnetic properties and electrochemical behavior are close to Re(I) analogs. This opens the prospect of using paramagnetic cymantrenes as prototypes in the design of Re(I) half-sandwiched derivatives for theranostics, where therapy is combined with diagnostics by magnetic resonance imaging due to the contrast properties of nitroxide radicals. 相似文献
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Viktor A. Ilin Elena V. Pyzhik Anton B. Balakhonov Maksim A. Kiryushin Evgeniya V. Shcherbatova Andrey A. Kuznetsov Pavel A. Kostin Andrey V. Golovin Vladimir A. Korshun Vladimir A. Brylev Kseniya A. Sapozhnikova Alexey M. Kopylov Galina V. Pavlova Igor N. Pronin 《Molecules (Basel, Switzerland)》2023,28(1)
Central nervous system tumors related to gliomas are of neuroectodermal origin and cover about 30% of all primary brain tumors. Glioma is not susceptible to any therapy and surgical attack remains one of the main approaches to its treatment. Preoperative tumor imaging methods, such as positron emission tomography (PET), are currently used to distinguish malignant tissue to increase the accuracy of glioma removal. However, PET is lacking a specific visualization of cells possessing certain molecular markers. Here, we report an application of aptamers to enhancing specificity in imaging tumor cells bearing the epidermal growth factor receptor (EGFR). Glioblastoma is characterized by increased EGFR expression, as well as mutations of this receptor associated with active division, migration, and adhesion of tumor cells. Since 2021, EGFR has been included into the WHO classification of gliomas as a molecular genetic marker. To obtain conjugates of aptamers GR20 and GOL1-specific to EGFR, a 4-[18F]fluorobenzylazide radiotracer was used as a synthon. For the production of the synthon, a method of automatic synthesis on an Eckert & Ziegler research module was adapted and modified using spirocyclic iodonium ylide as a precursor. Conjugation of 4-[18F]fluorobenzylazide and alkyne-modified aptamers was carried out using Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) with/without the TBTA ligand. As a result, it was possible to obtain 18F-labelled conjugates with 97% radiochemical purity for [18F]FB-GR20 and 98% for [18F]FB-GOL1. The obtained conjugates can be used for further studies in PET analysis on model animals with grafted glioblastoma. 相似文献
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Kseniya Revunova Dr. Georgii I. Nikonov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(3):839-845
Simple bases (KOtBu, KOH) catalyze the silane‐promoted reduction of ketones and esters to alcohols and of aldimines to amines. The inexpensive silane PMHS (polymethylhydrosiloxane) can be used as the reducing reagent. Double and triple bonds, as well as nitro‐ and cyano‐groups are tolerated. Careful dosing of the silane allows for chemoselective reduction of a more reactive group in the presence of a less reactive group (for example, aldehyde reduction in the presence of ketone/ketone reduction in the presence of ester group). Mechanistic studies showed that addition of base to silanes leads to silicate species, which are the acting reducing agents. Under basic conditions, hydrosiloxanes (tetramethyldisiloxane, TMDS; PMHS) convert into simple silanes (H2SiMe2, H3SiMe), making this a practical method to generate these challenging silanes. 相似文献
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Kseniya V. Zherikova Ludmila N. Zelenina Natalia B. Morozova Tamara P. Chusova 《Journal of Thermal Analysis and Calorimetry》2012,108(3):1325-1329
Complexes of ruthenium(III) with the following beta-diketone derivatives: 2,4-pentanedione (Ru(acac)3), 1,1,1,6,6,6-hexafluoro-2,4-pentanedione (Ru(hfac)3), and 2-methoxy-2,6-dimethyl-3,5-heptanedione (Ru(mdhd)3) were synthesized, purified, and identified by chemical analysis and melting points. By difference-scanning calorimetry (DSC) in vacuum the thermodynamic characteristics of melting processes were defined. Using the static method with quartz membrane zero-manometer, the temperature dependencies of saturated and unsaturated vapor pressure were obtained for Ru(hfac)3. The standard thermodynamic characteristics of vaporization processes enthalpy ?H T* and entropy ?S° T* were determined. 相似文献
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Mikhail V. Dubovis Gennady F. Rudakov Alexander S. Kulagin Kseniya V. Tsarkova Sergey V. Popkov Alexander S. Goloveshkin Georgiy V. Cherkaev 《Tetrahedron》2018,74(6):672-683
Based on the deoxygenation reaction of 1-(1-tert-butyl-3-nitroazetidine-3-yl)-1H-1,2,3-triazoles a new method for the synthesis of substituted 1-(1H-imidazole-4-yl)-1H-1,2,3-triazoles has been developed. Fungicidal activity of these compounds has been investigated at a range of phytopathogenic fungi. 相似文献
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Magnesium Hexafluoridozirconates MgZrF6·5H2O,MgZrF6·2H2O,and MgZrF6: Structures,Phase Transitions,and Internal Mobility of Water Molecules 下载免费PDF全文
Andrey V. Gerasimenko Kseniya A. Gaivoronskaya Arseny B. Slobodyuk Nina A. Didenko 《无机化学与普通化学杂志》2017,643(22):1785-1792
The MgZrF6 · n H2O (n = 5, 2 and 0) compounds were studied by the methods of X‐ray diffraction and 19F, MAS 19F, and 1H NMR spectroscopy. At room temperature, the compound MgZrF6 · 5H2O has a monoclinic C‐centered unit cell and is composed of isolated chains of edge‐sharing ZrF8 dodecahedra reinforced with MgF2(H2O)4 octahedra and uncoordinated H2O molecules and characterized by a disordered system of hydrogen bonds. In the temperature range 259 to 255 K, a reversible monoclinic ? two‐domain triclinic phase transition is observed. The phase transition is accompanied with ordering of hydrogen atoms positions and the system of hydrogen bonds. The structure of MgZrF6 · 2H2O comprises a three‐dimensional framework consisting of chains of edge‐sharing ZrF8 dodecahedra linked to each other through MgF4(H2O)2 octahedra. The compound MgZrF6 belongs to the NaSbF6 type and is built from regular ZrF6 and MgF6 octahedra linked into a three‐dimensional framework through linear Zr–F–Mg bridges. The peaks in 19F MAS spectra were attributed to the fluorine structural positions. The motions of structural water molecules were studied by variable‐temperature 1H NMR spectroscopy. 相似文献
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A skeletal carbenoid rearrangement of the gem-bromochlorospiropentanes in the presence of methyllithium has been studied. The synthetic and mechanistic aspects of this rearrangement as well as the influence of the halogen atom nature on the reaction pathway are discussed. 相似文献