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1.
Andrei K. Yudin 《Chemical science》2015,6(1):30-49
A noticeable increase in molecular complexity of drug targets has created an unmet need in the therapeutic agents that are larger than traditional small molecules. Macrocycles, which are cyclic compounds comprising 12 atoms or more, are now recognized as molecules that “are up to the task” to interrogate extended protein interfaces. However, because macrocycles (particularly the ones based on peptides) are equipped with large polar surface areas, achieving cellular permeability and bioavailability is anything but straightforward. While one might consider this to be the Achilles'' heel of this class of compounds, the synthetic community continues to develop creative approaches toward the synthesis of macrocycles and their site-selective modification. This perspective provides an overview of both mechanistic and structural issues that bear on macrocycles as a unique class of molecules. The reader is offered a historical foray into some of the classic studies that have resulted in the current renaissance of macrocycles. In addition, an attempt is made to overview the more recent developments that give hope that macrocycles might indeed turn into a useful therapeutic modality. 相似文献
2.
Dr. Sungjoon Huh Dr. George J. Saunders Prof. Andrei K. Yudin 《Angewandte Chemie (International ed. in English)》2023,62(5):e202214729
Site-selective transformations of densely functionalized scaffolds have been a topic of intense interest in chemical synthesis. Herein we have repurposed the rarely used Cornforth rearrangement as a tool to effect a single-atom ring contraction in cyclic peptide backbones. Investigations into the kinetics of the rearrangement were carried out to understand the impact of electronic factors, ring size, and linker type on the reaction efficiency. Conformational analysis was undertaken and showed how subtle differences in the peptide backbone result in substrate-dependent reaction profiles. This methodology can now be used to perform conformation-activity studies. The chemistry also offers an opportunity to install building blocks that are not compatible with traditional C-to-N iterative synthesis of macrocycle precursors. 相似文献
3.
Nilgün KABAY Yasemin BAYGU Metin AK zzet KARA EsraNur KAYA Mahmut DURMU Yaar G
K 《Turkish Journal of Chemistry》2021,45(1):143
The current study describes the synthesis, electrochemical, computational, and photochemical properties of octa (3-hydroxypropylthio) substituted cobalt (II) ( 4 ), copper (II) ( 5 ), nickel (II) ( 6 ) and zinc(II) ( 7 ) phthalocyanine derivatives. These novel compounds were characterized by elemental analysis,1H,13C NMR, FT-IR, UV-Vis, and MS. The redox behaviors of these metallo-phthalocyanines were investigated by the cyclic voltammetric method. The optimized molecular structure and gauge-including atomic orbital (GIAO)1H and13C NMR chemical shift values of these phthalocyanines in the ground state had been calculated by using B3LYP/6–31G(d,p) basis set. The outcomes of the optimized molecular structure were given and compared with the experimental NMR values. The photochemical properties including photodegradation and singlet oxygen generation of zinc(II) phthalocyanine were studied in DMSO solution for the determination of its photosensitizer behaviors. 相似文献
4.
Parameterization of electrostatic interactions for molecular dynamics simulations of heterocyclic polymers 下载免费PDF全文
Victor M. Nazarychev Sergey V. Larin Alexander V. Yakimansky Natalia V. Lukasheva Andrey A. Gurtovenko Iosif V. Gofman Vladimir E. Yudin Valentin M. Svetlichnyi Jose M. Kenny Sergey V. Lyulin 《Journal of Polymer Science.Polymer Physics》2015,53(13):912-923
The paper focuses on the problem of electrostatic interactions in molecular dynamics simulations of thermal properties of heterocyclic polymers. The study focuses on three thermoplastic polyimides synthesized on the basis of 1,3‐bis‐(3′,4‐dicarboxyphenoxy)benzene (dianhydride R) and three diamines: 4,4′‐bis‐(4″‐aminophenoxy) diphenylsulfone (diamine BAPS), 4,4′‐bis‐(4″‐aminophenoxy) biphenyl (diamine BAPB), and 4,4′‐bis‐(4''‐aminophenoxy) diphenyloxide (diamine BAPO). In the molecular dynamics simulations these polyimides were described by the Gromos53a5 force field. To parameterize the electrostatic interactions four methods of calculating the partial atomic charges were chosen: B3LYP/6–31G*(Mulliken), AM1(Mulliken), HF/6–31G*(Mulliken), and HF/6–31G*(ChelpG). As our parameterization is targeted to reproduce thermal properties of the thermoplastic polyimides, the choice of proper partial charges was finalized on a basis of the closest match between computational and experimental data for the thermal expansion coefficients of the polyimides below glass transition temperatures. Our finding clearly show that the best agreement with experimental data is achieved with the Mulliken partial atomic charges calculated by the Hartree‐Fock method with 6–31G* basis set. Furthermore, in addition to the thermal expansion coefficients this set of partial atomic charges predicts an experimentally observed relationship between glass transition temperatures of the three polyimides under study: . A mechanism behind the change in thermal properties upon the change in the chemical structure in considered polyimides may be related to an additional spatial ordering of sulfone groups due to dipole‐dipole interactions. Overall, the modified force‐field is proved to be suitable for accurate prediction of thermal properties of thermoplastic polyimides and can serve as a basis for building up atomistic theoretical models for describing other heterocyclic polymers in bulk. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 912–923 相似文献
5.
Barskaya E. S. Beloglazkina E. K. Mazhuga A. G. Yudin I. V. Zyk N. V. 《Russian Chemical Bulletin》2015,64(8):1975-1977
Russian Chemical Bulletin - Reflux of imidazole-2-carboxaldehyde, 1-methylimidazole-2-carboxaldehyde, imidazole4-carboxaldehyde, or 5-bromopyridine-2-carboxaldehyde with 2-aminothiophenol in... 相似文献
6.
Rostov State University Scientific-Research Institute of Mechanics and Applied Mathematics, Rostovon-Don. Translated from Prikladnaya Mekhanika, Vol. 25, No. 12, pp. 63–68, December, 1989. 相似文献
7.
Physics of Atomic Nuclei - The role of weakly bound neutral clusters, such as dineutrons and tetraneutrons, in matter of high density and high temperature is discussed. Under such conditions, which... 相似文献
8.
Moskalyuk O. A. Semenova I. V. Yudin V. E. Beltukov Y. M. Saprykina N. N. Elokhovskii V. Yu. 《Technical Physics》2019,64(2):213-219
Technical Physics - Samples of composites based on polystyrene with addition of halloysite nanotubes, mica, and montmorillonite aluminosilicates are obtained and the influence of these fillers on... 相似文献
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