394 research outputs found
Синтез, дослідження 6-((5-фенетил-4-R-1,2,4-триазол-3-ілтіо)піридин-3-іл)-(алкіл, гетерил)метанімінів та їх похідних
In the pharmaceutical practice directly related to the search of biological active substances and their introduction into medicine or veterinary it is generally recognized that a successful choice of the research object is a prerequisite for a positive final outcome to create original effective and low-toxic drugs. At present, derivatives of 1,2,4-triazoles containing pyridine deserve special attention. That is why the synthesis and study of physicochemical properties of new compounds, which contain 1,2,4-triazole and pyridine rings, are important tasks of modern synthetic and pharmaceutical chemistry.Aim. To study the reactions associated with formation and transformation of 6-((5-phenethyl-4-R-1,2,4-triazole-3-ylthio)pyridine-3-yl)-(alkyl-, heteryl)methanimines and their recovery, study physicochemical properties of new compounds synthesized. Materials and methods. 6-((5-phenethyl-4-R-1,2,4-triazole-3-ylthio)pyridine-3-yl)-(alkyl-, heter-yl)methanimines were obtained by the mixture from 6-(5-phenethyl-4-R-1,2,4-triazole-3-ylthio)pyridine-3-amine and aldehydes. The synthesis was carried out in the acetic acid medium. The mixture was kept at room temperature for 6 h. 6-((5-phenethyl-4-R-1,2,4-triazole-3-ylthio)pyridine-3-yl)-(alkyl-, heteryl)methanimines were reduced in the 1,4-dioxane medium. As a reducing agent sodium borohydride was used. Results and discussion. As a result of synthetic transformations 17 new compounds have been obtained, the structure of the compounds synthesized has been confirmed by modern complex of physicochemical methods of analysis (IR-spectrophotometry, elemental analysis), and their individuality has been proven on an Agilent 1260 Infinity HPLC high-performance liquid chromatograph equipped with an Agilent 6120 mass spectrometer.Conclusions. The preparative method for the synthesis of 6-((5-phenethyl-4-R-1,2,4-triazole-3-ylthio)pyridine-3-yl)-(alkyl-, heteryl)methanimines and 6-(5-phenethyl-4-R-1,2,4-triazole-3-ylthio)-N-(alkyl-, heteryl)pyridine-3-amines has been developed.В фармацевтической практике, непосредственно связанной с поиском биологически активных веществ и их введением в медицину или ветеринарию, общепринято, что успешный выбор объекта исследования является предпосылкой для положительного конечного результата, для создания оригинальных эффективных и малотоксичных лекарств. На данный момент особого внимания заслуживают производные 1,2,4-триазолов, которые содержат пиридин. Именно поэтому синтез и изучение физико-химических свойств новых соединений, содержащих 1,2,4-триазольное и пиридиновое кольца, являются важной задачей современной синтетической и фармацевтической химии.Цель. Изучить реакцию образования 6-((5-фенетил-4-R-1,2,4-триазол-3-илтио)пиридин-3-ил)-(алкил, гетерил)метаниминов и их селективного восстановления, исследовать физические и химические свойства новых синтезированных соединений.Материалы и методы. Для получения 6-((5-фенетил-4-R-1,2,4-триазол-3-илтио)пиридин-3-ил)-(алкил-, гетерил)метаниминов использовали 6-(5-фенетил-4-R-1,2,4-триазол-3-илтио)пиридин-3-амины и альдегиды. Синтез проводился в среде кислоты уксусной. Смесь оставляли при комнатной температуре на 6 часов. 6-((5-Фенетил-4-R-1,2,4-триазол-3-илтио)пиридин-3-ил)-(алкил-, гетерил)метанимины были восстановлены в среде 1,4-диоксана. В качестве восстановителя был использован натрия боргидрид.Результаты и их обсуждение. В результате синтетических превращений получено 17 новых соединений, структуру синтезированных соединений подтверждено благодаря современному комплексу физико-химических методов анализа (ИК-спектрофотометрии, элементного анализа), а их индивидуальность подтверждена исследованием на высокопроизводительном жидком хроматографе Agilent 1260 Infinity HPLC, оборудованном масс-спектрометром Agilent 6120.Выводы. Разработан препаративный метод синтеза 6-((5-фенетил-4-R-1,2,4-триазол-3-илтио)пиридин-3-ил)-(алкил-, гетерил)метаниминов и 6-(5-фенетил-4-R-1,2,4-триазол-3-илтио)-N- (алкил-, гетерил)пиридин-3-аминов.У фармацевтичній практиці, яка безпосередньо пов’язана з пошуком біологічно активних речовин та їх введенням у медицину або ветеринарію, загальним є те, що успішний вибір об’єкта дослідження є необхідною умовою для позитивного кінцевого результату та для створення оригінальних ефективних та малотоксичних препаратів. На цьому етапі на особливу увагу заслуговують похідні 1,2,4-триазолів, що містять піридин. Саме тому синтез та вивчення фізико-хімічних властивостей нових сполук, що містять 1,2,4-триазольний та піридиновий фрагмент, є важливими завданнями сучасної синтетичної та фармацевтичної хімії.Мета. Вивчити реакцію утворення 6-((5-фенетил-4-R-1,2,4-триазол-3-ілтіо)піридин-3-іл)-(алкіл, гетерил)метанімінів та їх селективного відновлення, дослідити фізичні та хімічні властивості нових синтезованих сполук.Матеріали та методи. Для отримання 6-((5-фенетил-4-R-1,2,4-триазол-3-ілтіо)піридин-3-іл)-(алкіл-, гетерил)метанімінів використано 6-(5-фенетил-4R-1,2,4-триазол-3-ілтіо)піридин-3-аміни та альдегіди. Синтез проводився в середовищі кислоти оцтової. Суміш залишали при кімнатній температурі на 6 годин. 6-((5-Фенетил-4-R-1,2,4-триазол-3-ілтіо)піридин-3-іл)-(алкіл-, гетерил)метаніміни були відновлені в середовищі 1,4-діоксану. В якості відновника використано натрію боргідрид.Результати та їх обговорення. В результаті синтетичних перетворень отримано 17 нових сполук, структуру синтезованих сполук підтверджено завдяки сучасному комплексу фізико-хімічних методів аналізу (ІЧ-спектрофотометрії, елементного аналізу), а їх індивідуальність підтверджена дослідженням на високопродуктивному рідинному хроматографі Agilent 1260 Infinity HPLC, обладнаному мас-спектрометром Agilent 6120.Висновки. Розроблено препаративний метод синтезу 6-((5-фенетил-4-R-1,2,4-триазол-3-ілтіо)піридин-3-іл)-(алкіл-, гетерил)метанімінів і 6-(5-фенетил-4-R-1,2,4-триазол-3-ілтіо)-N-(алкіл-, гетерил)піридин-3-амінів
КОМП’ЮТЕРНЕ ПРОГНОЗУВАННЯ ГОСТРОЇ ТОКСИЧНОСТІ ПОХІДНИХ 5-ФЕНЕТИЛ-4-R-3-ТІО(АМІНО)-1,2,4-ТРІАЗОЛУ ЗАВДЯКИ GUSAR-ONLINE ПРОГНОЗУ
An important step in the development of a new drug is the prediction of its toxicity by computer screening using the program GUSAR-online. The purpose of this work is an online prediction of acute toxicity among new derivatives of 5-phenethyl-4-R-3-thio(amino) 1,2,4-triazoles. Computer prediction of acute toxicity of 5-phenethyl-4-R-3-thio(amino)- 1,2,4-triazole derivatives was performed according to the structural formulas of the compounds in the online version of the GUSAR-online program.GUSAR-online prediction for 5-phenethyl-4-R-3-thio(amino)-1,2,4- triazole derivatives was performed during the research. It was found that the average lethal dose of LD50 is from 56.1 to 2396.0 mg / kg. Based on this, all compounds are low-toxic and virtually non-toxic substances.An important step in the development of a new drug is the prediction of its toxicity by computer screening using the program GUSAR-online. The purpose of this work is an online prediction of acute toxicity among new derivatives of 5-phenethyl-4-R-3-thio(amino) 1,2,4-triazoles. Computer prediction of acute toxicity of 5-phenethyl-4-R-3-thio(amino)- 1,2,4-triazole derivatives was performed according to the structural formulas of the compounds in the online version of the GUSAR-online program.GUSAR-online prediction for 5-phenethyl-4-R-3-thio(amino)-1,2,4- triazole derivatives was performed during the research. It was found that the average lethal dose of LD50 is from 56.1 to 2396.0 mg / kg. Based on this, all compounds are low-toxic and virtually non-toxic substances
Elastic constants of borocarbides. New approach to acoustic Measurement technique
A new version of the phase method of determining the sound velocity is
proposed and implemented. It utilizes the ``Nonius'' measurement technique and
can give acceptable accuracy (~1%) in samples of submillimeter size.
Measurements of the sound velocity are made in single-crystal samples of the
borocarbides RNi2B2C (R = Y,Lu,Ho). The elastic constants and the Debye
temperature are calculated.Comment: 5 figures, 2 table
On the analyticity and Gevrey class regularity up to the boundary for the Euler Equations
We consider the Euler equations in a three-dimensional Gevrey-class bounded
domain. Using Lagrangian coordinates we obtain the Gevrey-class persistence of
the solution, up to the boundary, with an explicit estimate on the rate of
decay of the Gevrey-class regularity radius
Professionogram in professional pedagogical preparation of the choreographic headamateur team
The article deals with the problem of professional competence of the head of a creative (choreographic) team.В статье рассматривается проблема профессиональной компетентности руководителя творческого (хореографического) коллектива
Separation of Oligosaccharides from Lotus Seeds via Medium-pressure Liquid Chromatography Coupled with ELSD and DAD
peer-reviewedLotus seeds were identified by the Ministry of Public Health of China as both food and medicine. One general function of lotus seeds is to improve intestinal health. However, to date, studies evaluating the relationship between bioactive compounds in lotus seeds and the physiological activity of the intestine are limited. In the present study, by using medium pressure liquid chromatography coupled with evaporative light-scattering detector and diode-array detector, five oligosaccharides were isolated and their structures were further characterized by electrospray ionization-mass spectrometry and gas chromatography-mass spectrometry. In vitro testing determined that LOS3-1 and LOS4 elicited relatively good proliferative effects on Lactobacillus delbrueckii subsp. bulgaricus. These results indicated a structure-function relationship between the physiological activity of oligosaccharides in lotus seeds and the number of probiotics applied, thus providing room for improvement of this particular feature. Intestinal probiotics may potentially become a new effective drug target for the regulation of immunity
Mapping of Mycobacterium tuberculosis Complex Genetic Diversity Profiles in Tanzania and Other African Countries
The aim of this study was to assess and characterize Mycobacterium tuberculosis complex (MTBC) genotypic diversity in Tanzania, as well as in neighbouring East and other several African countries. We used spoligotyping to identify a total of 293 M. tuberculosis clinical isolates (one isolate per patient) collected in the Bunda, Dar es Salaam, Ngorongoro and Serengeti areas in Tanzania. The results were compared with results in the SITVIT2 international database of the Pasteur Institute of Guadeloupe. Genotyping and phylogeographical analyses highlighted the predominance of the CAS, T, EAI, and LAM MTBC lineages in Tanzania. The three most frequent Spoligotype International Types (SITs) were: SIT21/CAS1-Kili (n = 76; 25.94%), SIT59/LAM11-ZWE (n = 22; 7.51%), and SIT126/EAI5 tentatively reclassified as EAI3-TZA (n = 18; 6.14%). Furthermore, three SITs were newly created in this study (SIT4056/EAI5 n = 2, SIT4057/T1 n = 1, and SIT4058/EAI5 n = 1). We noted that the East-African-Indian (EAI) lineage was more predominant in Bunda, the Manu lineage was more common among strains isolated in Ngorongoro, and the Central-Asian (CAS) lineage was more predominant in Dar es Salaam (p-value<0.0001). No statistically significant differences were noted when comparing HIV status of patients vs. major lineages (p-value = 0.103). However, when grouping lineages as Principal Genetic Groups (PGG), we noticed that PGG2/3 group (Haarlem, LAM, S, T, and X) was more associated with HIV-positive patients as compared to PGG1 group (Beijing, CAS, EAI, and Manu) (p-value = 0.03). This study provided mapping of MTBC genetic diversity in Tanzania (containing information on isolates from different cities) and neighbouring East African and other several African countries highlighting differences as regards to MTBC genotypic distribution between Tanzania and other African countries. This work also allowed underlining of spoligotyping patterns tentatively grouped within the newly designated EAI3-TZA lineage (remarkable by absence of spacers 2 and 3, and represented by SIT126) which seems to be specific to Tanzania. However, further genotyping information would be needed to confirm this specificity
The Inviscid Limit and Boundary Layers for Navier-Stokes Flows
The validity of the vanishing viscosity limit, that is, whether solutions of
the Navier-Stokes equations modeling viscous incompressible flows converge to
solutions of the Euler equations modeling inviscid incompressible flows as
viscosity approaches zero, is one of the most fundamental issues in
mathematical fluid mechanics. The problem is classified into two categories:
the case when the physical boundary is absent, and the case when the physical
boundary is present and the effect of the boundary layer becomes significant.
The aim of this article is to review recent progress on the mathematical
analysis of this problem in each category.Comment: To appear in "Handbook of Mathematical Analysis in Mechanics of
Viscous Fluids", Y. Giga and A. Novotn\'y Ed., Springer. The final
publication is available at http://www.springerlink.co
Polyglutamine Induced Misfolding of Huntingtin Exon1 is Modulated by the Flanking Sequences
Polyglutamine (polyQ) expansion in exon1 (XN1) of the huntingtin protein is linked to Huntington's disease. When the number of glutamines exceeds a threshold of approximately 36–40 repeats, XN1 can readily form amyloid aggregates similar to those associated with disease. Many experiments suggest that misfolding of monomeric XN1 plays an important role in the length-dependent aggregation. Elucidating the misfolding of a XN1 monomer can help determine the molecular mechanism of XN1 aggregation and potentially help develop strategies to inhibit XN1 aggregation. The flanking sequences surrounding the polyQ region can play a critical role in determining the structural rearrangement and aggregation mechanism of XN1. Few experiments have studied XN1 in its entirety, with all flanking regions. To obtain structural insights into the misfolding of XN1 toward amyloid aggregation, we perform molecular dynamics simulations on monomeric XN1 with full flanking regions, a variant missing the polyproline regions, which are hypothesized to prevent aggregation, and an isolated polyQ peptide (Qn). For each of these three constructs, we study glutamine repeat lengths of 23, 36, 40 and 47. We find that polyQ peptides have a positive correlation between their probability to form a β-rich misfolded state and their expansion length. We also find that the flanking regions of XN1 affect its probability to^x_page_count=28 form a β-rich state compared to the isolated polyQ. Particularly, the polyproline regions form polyproline type II helices and decrease the probability of the polyQ region to form a β-rich state. Additionally, by lengthening polyQ, the first N-terminal 17 residues are more likely to adopt a β-sheet conformation rather than an α-helix conformation. Therefore, our molecular dynamics study provides a structural insight of XN1 misfolding and elucidates the possible role of the flanking sequences in XN1 aggregation
One dimensional cuts through multidimensional potential energy surfaces by tunable x rays
The concept of the potential energy surface PES and directional reaction coordinates is the backbone of our description of chemical reaction mechanisms. Although the eigenenergies of the nuclear Hamiltonian uniquely link a PES to its spectrum, this information is in general experimentally inaccessible in large polyatomic systems. This is due to near degenerate rovibrational levels across the parameter space of all degrees of freedom, which effectively forms a pseudospectrum given by the centers of gravity of groups of close lying vibrational levels. We show here that resonant inelastic x ray scattering RIXS constitutes an ideal probe for revealing one dimensional cuts through the ground state PES of molecular systems, even far away from the equilibrium geometry, where the independent mode picture is broken. We strictly link the center of gravity of close lying vibrational peaks in RIXS to a pseudospectrum which is shown to coincide with the eigenvalues of an effective one dimensional Hamiltonian along the propagation coordinate of the core excited wave packet. This concept, combined with directional and site selectivity of the core excited states, allows us to experimentally extract cuts through the ground state PES along three complementary directions for the showcase H2O molecul
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