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521.
N. E. Kuz’mina E. S. Osipova V. S. Kuz’min V. B. Sitnikov 《Russian Chemical Bulletin》2006,55(9):1523-1529
By superposition of the molecules of opiate receptor ligands of various structural classes, three regions responsible for
the nonselective ligand affinity were distinguished in the opiate pharmacophore. Spatial arrangement features, electronic
properties, the capability of H-bonding and hydrophobic and electrostatic interactions of these regions were determined. The
set of geometric parameters found can be used as a criterion for estimation of the opiate activity in simulation of new types
of ligands.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1469–1475, September, 2006. 相似文献
522.
523.
Yu. N. Zhukov A. R. Khomutov T. I. Osipova R. M. Khomutov 《Russian Chemical Bulletin》1999,48(7):1348-1351
Phosphinic analogs of the key compounds of the metabolism of methionine were synthesized. The compounds obtained were selectively
oxidized either at the phosphinic group or at the sulfur-containing fragment.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1360–1363, July, 1999. 相似文献
524.
The stress-strain equation of state for a material with dissolved hydrogen is derived within a two-component continuum model.
It is demonstrated that, for the parameters corresponding to conventional metals, it has the shape of a loop similar to the
van der Waals loop. On this basis, it is concluded that hydrogen embrittlement of materials under load is a typical first-order
phase transition and, therefore, occurs through nucleation of a new phase. Thermodynamic and kinetic theories of this transition
are developed, and time dependences of all the main characteristics of this process are calculated. 相似文献
525.
Nadezhda S. Baleeva Snizhana O. Zaitseva Konstantin S. Mineev Anastasia V. Khavroshechkina Marina B. Zagudaylova Mikhail S. Baranov 《Tetrahedron letters》2019,60(5):456-459
Fluorescent dyes are a significant research tool with various applications in modern science. However, many experiments require the preparation of covalent dye conjugates, which is impossible without the presence of a functional group on the dye molecule. Unfortunately, the introduction of such groups is often a complicated task. Herein, we report a novel approach for the introduction of functional groups into fluorescent dyes, based on the [2+3]-cycloaddition reaction of “terminal” enamines with azides. The synthesis of such “terminal” enamines is carried out by the condensation of formamide acetals with a methyl group that is influenced by a strong electron withdrawing group. Thus, the proposed functionalization technique requires only the presence of a methyl group in the relevant position of the initial non-functionalized fluorescent dye. 相似文献
526.
Roman A. Irgashev Nadezhda S. Demina Nikita A. Kazin Gennady L. Rusinov 《Tetrahedron letters》2019,60(16):1135-1138
Two new classes of heteroacenes, namely benzo[4′,5′]thieno[2′,3′:4,5]thieno[3,2-b]quinolines and benzo[4′,5′]thieno[2′,3′:4,5]thieno[3,2-b][1,8]naphthyridines, have been formed using the Friedländer reaction to annulate the benzo[b]thieno[2,3-d]thiophene scaffold to quinoline or 1,8-naphthyridine fragments. In accordance with this synthetic strategy, benzo[b]thieno[2,3-d]thiophen-3(2H)-ones were treated with 2-aminobenzaldehydes or 2-aminonicotinaldehyde in the presence of pyrrolidine in glacial acetic acid at reflux to give the desired quinoline- or 1,8-naphthyridine-fused compounds, respectively. The optical and electrochemical properties of selected heteroacenes were determined. 相似文献
527.
Sergey O. Bachurin Galina F. Makhaeva Elena F. Shevtsova Alexey Yu. Aksinenko Vladimir V. Grigoriev Pavel N. Shevtsov Tatiana V. Goreva Tatiana A. Epishina Nadezhda V. Kovaleva Elena A. Pushkareva Natalia P. Boltneva Sofya V. Lushchekina Alexey V. Gabrelyan Vladimir L. Zamoyski Lyudmila G. Dubova Elena V. Rudakova Vladimir P. Fisenko Elena V. Bovina Rudy J. Richardson 《Molecules (Basel, Switzerland)》2021,26(18)
A new series of conjugates of aminoadamantane and γ-carboline, which are basic scaffolds of the known neuroactive agents, memantine and dimebon (Latrepirdine) was synthesized and characterized. Conjugates act simultaneously on several biological structures and processes involved in the pathogenesis of Alzheimer’s disease and some other neurodegenerative disorders. In particular, these compounds inhibit enzymes of the cholinesterase family, exhibiting higher inhibitory activity against butyrylcholinesterase (BChE), but having almost no effect on the activity of carboxylesterase (anti-target). The compounds serve as NMDA-subtype glutamate receptor ligands, show mitoprotective properties by preventing opening of the mitochondrial permeability transition (MPT) pore, and act as microtubule stabilizers, stimulating the polymerization of tubulin and microtubule-associated proteins. Structure–activity relationships were studied, with particular attention to the effect of the spacer on biological activity. The synthesized conjugates showed new properties compared to their prototypes (memantine and dimebon), including the ability to bind to the ifenprodil-binding site of the NMDA receptor and to occupy the peripheral anionic site of acetylcholinesterase (AChE), which indicates that these compounds can act as blockers of AChE-induced β-amyloid aggregation. These new attributes of the conjugates represent improvements to the pharmacological profiles of the separate components by conferring the potential to act as neuroprotectants and cognition enhancers with a multifunctional mode of action. 相似文献
528.
Zarina M. Efimenko Anton V. Rozhkov Vitalii V. Suslonov Maxim L. Kuznetsov Vadim Yu. Kukushkin Nadezhda A. Bokach 《Molecules (Basel, Switzerland)》2021,26(18)
The 3-Iodo-1-nitrosonaphthalene-2-ol (I-NON) was obtained by the copper(II)-mediated iodination of 1-nitroso-2-naphthol (NON). The suitable reactants and optimized reaction conditions, providing 94% NMR yield of I-NON, included the usage of Cu(OAc)2·H2O and 1:2:8 CuII/NON/I2 molar ratio between the reactants. The obtained I-NON was characterized by elemental analyses (C, H, N), high-resolution ESI+-MS, 1H and 13C{1H} NMR, FTIR, UV-vis spectroscopy, TGA, and X-ray crystallography (XRD). The copper(II) complexes bearing deprotonated I-NON were prepared as follows: cis-[Cu(I-NON–H)(I-NON)](I3) (1) was obtained by the reaction between Cu(NON-H)2 and I2 in CHCl3/MeOH, while trans-[Cu(I-NON–H)2] (2) was synthesized from I-NON and Cu(OAc)2 in MeOH. Crystals of trans-[Cu(I-NON–H)2(THF)2] (3) and trans-[Cu(I-NON–H)2(Py)2] (4) were precipitated from solutions of 2 in CHCl3/THF and Py/CHCl3/MeOH mixtures, respectively. The structures of 1 and 3–4 were additionally verified by X-ray crystallography. The characteristic feature of the structures of 1 and 3 is the presence of intermolecular halogen bonds with the involvement of the iodine center of the metal-bound deprotonated I-NON. The nature of the I···I and I···O contacts in the structures of 1 and 3, correspondingly, were studied theoretically at the DFT (PBE0-D3BJ) level using the QTAIM, ESP, ELF, NBO, and IGM methods. 相似文献
529.
A two-temperature model of optical excitation of acoustic pulses in conductors has been developed. According to this model, the energy of light at first is absorbed by free carriers and only then is the optical pulse energy transferred to long-wavelength phonons of the conductor lattice. It is shown that the shape of the acoustic pulse excited by a laser in conductors can be presented as a convolution of the laser pulse envelope and the transfer function. An analytical dependence of the transfer function on time is derived. 相似文献
530.
A. D. Avrorin A. V. Avrorin V. M. Aynutdinov R. Bannasch I. A. Belolaptikov V. B. Brudanin N. M. Budnev I. A. Danilchenko S. V. Demidov G. V. Domogatsky A. A. Doroshenko R. Dvornicky A. N. Dyachok Zh.-A. M. Dzhilkibaev L. Fajt S. V. Fialkovsky R. R. Gafarov O. N. Gaponenko K. V. Golubkov T. I. Gress Z. Honz K. G. Kebkal O. G. Kebkal K. V. Konishchev A. V. Korobchenko A. P. Koshechkin F. K. Koshel A. V. Kozhin V. F. Kulepov D. A. Kuleshov M. V. Milenin R. A. Mirgazov E. A. Osipova A. I. Panfilov L. V. Pan’kov E. N. Pliskovsky M. I. Rozanov E. V. Rjabov B. A. Shaybonov A. A. Sheifler M. D. Shelepov A. V. Skurihin O. V. Suvorova V. A. Tabolenko B. A. Tarashchansky S. A. Yakovlev A. V. Zagorodnikov V. L. Zurbanov 《Journal of Experimental and Theoretical Physics》2017,125(1):80-90
We have analyzed the neutrino events recoded in the deep-water neutrino experiment NT200 in Lake Baikal in five years of observations toward dark dwarf spheroidal galaxies (dSphs) in the southern hemisphere and the Large Magellanic Cloud (LMC). This analysis completes the series of works based on NT200 data in the search for a dark matter annihilation signal in astrophysical objects. We have found no significant excess in the number of observed events relative to the expected background from atmospheric neutrinos in all tested directions, in 22 dSphs and the LMC. For a sample of five selected dwarf galaxies we have performed a joint analysis of the data by the maximum likelihood method. We have obtained a correspondence of the observational data to the null hypothesis about the presence of only background events and established 90% confidence-level upper limits for the annihilation cross sections of dark matter particles with a mass from 30 GeV to 10 TeV in several annihilation channels both in the joint analysis of the selected sample of galaxies and in the analysis toward the LMC. The strongest constraints at a level of 7 × 10–21 cm3 s–1 have been obtained for the direction toward the LMC in the channel of annihilation into a pair of neutrinos. 相似文献