505 research outputs found

    Specific features of magnetic structure formation in orbitally degenerate BiMnO3 manganite

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    The orbital structure and magnetic ordering of the Jahn-Teller multiferroic BiMnO3 manganite have been theoretically studied. It is shown that the orbital structure depends not only on the nearest-neighbor oxygen environment of manganese ions, but also on their next-to-nearest neighbors. The orbital structure significantly influences the magnetic order that forms as a result of competition between ferromagnetic and antiferromagnetic exchange interactions. © 2013 Pleiades Publishing, Ltd

    Phosphorylation of betti base with diethyl chlorophosphate

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    © 2016, Pleiades Publishing, Ltd.Phosphoric acid derivatives containing chiral Betti base fragment were synthesized by reacting racemic and enantiopure N-Boc-protected 1-(α-aminobenzyl)-2-naphthols with diethyl chlorophosphate followed by deprotection

    Antioxidant defense system: regulation of metabolic processes, genetic determinants, methods of determination

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    An increase in peroxidation activity is considered as a nonspecific process characteristic of the pathogenesis of various diseases accompanied by antioxidant deficiency. As bioregulators that can increase defense, antioxidants are important links in a multi-stage system of regulation and coordination of various body functions. The structure and function of enzymes involved in the regulation of oxidative stress can be significantly affected by genetic polymorphism. To date, the role of genes encoding the activity of enzymes of the antioxidant system in the pathogenesis of many diseases remains unexplored, which is of great interest to researchers from various fields. The article presents a review and analysis of data from modern scientific literature on the role of antioxidant defense components in the regulation of metabolic processes, their genetic determinant, and summarizes data on modern methods for the determination of some antioxidants. When writing the review, the database of the scientific electronic library eLibrary was used, the keywords are oxidative stress, free radical oxidation, antioxidant protection, antioxidants, antioxidant enzymes, enzyme genes, antioxidant response element, research methods; filters – publication years 2012–2022, publications with full text, publications available for viewing; English-language database of medical and biological publications, created by the National Center for Biotechnology Information (NCBI), keywords – lipid peroxidation, antioxidant protection, antioxidants, antioxidant enzymes, enzyme genes, oxidative stress, metabolism, methods

    Chiral thiophosphorylated thioureas: Synthesis, structure, and cyclization reaction

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    © 2014 Wiley Periodicals, Inc. A number of chiral racemic and enanthiopure thiophosphorylated thioureas were synthesized by the reaction of 2-aminobutan-1-ol and 1-(a-aminobenzyl)-2-naphthol with O,O-diethyl thiophosphoryl isothiocyanate. It was found that such thioureas undergo the cyclization reaction under basic conditions with hydrogen sulfide elimination and the formation of thiophosphorylated oxasines. XRay single crystal diffraction revealed that the structure of thiourea is close to the prereaction state of the cyclization reaction

    Synthesis and antifungal activity of sulfides, sulfoxides, and sulfones based on (1S)-(-)-β-pinene

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    Attachment of 2-mercaptoethanol and thioglycolic acid methyl ester to the double bond of (1S)-(-)-β-pinene yielded pinane sulfides with the cis configuration. Oxidation of sulfides with m-chloroperbenzoic acid yielded the corresponding sulfoxides and sulfones. The resulting compounds were screened for antimycotic activity and the dynamics of changes in antifungal properties in sulfides-sulfoxide-sulfone series were studied. © 2010 Springer Science+Business Media, Inc

    The history of ethical regulation of biomedical research in the CIS member states

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    The history of development the ethical and legislative tools for regulation the biomedical research in the states-members of Commonwealth of Independent States (CIS) in the frame of the close collaboration the Forum for Ethics Committees in the Commonwealth of Independent States (FECCIS) and Inter-Parliamentary Assembly CIS (IPA CIS) is demonstrated in this article. The collaboration between FECCIS and IPA CIS stands on the unique experience of IPA CIS in the building of the new, humanistic legislation in the field of health care and on the initiatives of FECCIS to create a single legal space inside and outside of the CIS region. The necessity to promote the dignity, rights, and well-being of human participants in health research was the real reason for creation the Model Law «On the Protection of Human Rights and Dignity in Biomedical Research in the CIS». The process of the law creation, its direction, structure, compliance with international ethical standards and implementation in the local legislation of CIS states are analysed by the main authors of Model Law «On the Protection of Human Rights and Dignity in Biomedical Research in the CIS» and presented in this review

    Monoterpenoids dithiophosphates. Synthesis and biological activity

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    O,O-Dialkyldithiophosphoric acids adds at the double bond of the racemic camphene and (+)- limonene in the presence of Lewis acids in accordance with the Markownikoff rule with the formation of Sterpenyl esters of dithiophosphoric acids. The reaction with camphene is accompanied by the rearrangement of camphane structure to that of bornane. Addition of dithiophosphoric acid to (+)-limonene proceeds with the participation of the exocyclic double bond. Toxic and genotoxic properties of the monoterpenoid dithiophosphates were studied. © Pleiades Publishing, Ltd., 2010

    When two symmetrically independent molecules must be different: "crystallization-induced diastereomerization" of chiral pinanyl sulfone

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    According to X-ray data, homochiral pinanyl sulfone crystallizes as an asymmetric dimer formed by pairwise H-bonds involving stereochemically different oxygen atoms of sulfonyl groups of molecules A and B. Thus, a pro-R atom is invoked for the construction of a relevant H-bond in molecule A, but in the case of molecule B only a pro-S atom is involved. Newly formed chiral sulfur atoms take opposite chirality in molecules A and B, while the configuration of the pinane skeleton remains unchanged. Such a stereochemical transformation is called "crystallization-induced diastereomerization". The stability of the asymmetric dimer found in the crystal was evaluated within the framework of DFT (B3LYP, 6-31G (d,p)) and studied via IR spectroscopy in solution. This journal is © the Partner Organisations 2014

    Synthesis of S-containing derivatives of the sesquiterpene lactone Britanin

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    The optimal method for isolating the sesquiterpene lactone britanin from the aerial part of Inula britannica L. (Asteraceae) was developed. Britanin was functionalized by reacting it with methyl mercaptoacetate. ©2005 Springer Science+Business Media, Inc
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