structural formulas
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2021 ◽  
Vol 23 (1) ◽  
pp. 406
Author(s):  
Andrey S. Erst ◽  
Alexander A. Chernonosov ◽  
Natalia V. Petrova ◽  
Maxim S. Kulikovskiy ◽  
Svetlana Yu. Maltseva ◽  
...  

Aqueous-ethanol extracts (70%) from the leaves of Eranthis longistipitata Regel. (Ranunculaceae Juss.)—collected from natural populations of Kyrgyzstan—were studied by liquid chromatography with high-resolution mass spectrometry (LC-HRMS). There was no variation of the metabolic profiles among plants that were collected from different populations. More than 160 compounds were found in the leaves, of which 72 were identified to the class level and 58 to the individual-compound level. The class of flavonoids proved to be the most widely represented (19 compounds), including six aglycones [quercetin, kaempferol, aromadendrin, 6-methoxytaxifolin, phloretin, and (+)-catechin] and mono- and diglycosides (the other 13 compounds). In the analyzed samples of E. longistipitata, 14 fatty acid–related compounds were identified, but coumarins and furochromones that were found in E. longistipitata were the most interesting result; furochromones khelloside, khellin, visnagin, and cimifugin were found in E. longistipitata for the first time. Coumarins 5,7-dihydroxy-4-methylcoumarin, scoparone, fraxetin, and luvangetin and furochromones methoxsalen, 5-O-methylvisammioside, and visamminol-3′-O-glucoside were detected for the first time in the genus Eranthis Salisb. For all the above compounds, the structural formulas are given. Furthermore, detailed information (with structural formulas) is provided on the diversity of chromones and furochromones in other representatives of Eranthis. The presence of chromones in plants of the genus Eranthis confirms its closeness to the genus Actaea L. because chromones are synthesized by normal physiological processes only in these members of the Ranunculaceae family.


Author(s):  
Ольга Евгеньевна Баранова

Центральное место в теории конформных отображений занимает решение экстремальных задач на классах однолистных отображений. В известных классах нормированных голоморфных функций $S$ и $C$ решение «проблемы коэффициентов» связано с получением точных оценок модулей тейлоровских коэффициентов элементов классов. Аналогичные задачи ставятся для классов локально однолистных отображений. В.Г.Шеретов ввел в рассмотрение классы локально конформных отображений, генерируемых с помощью интегральных структурных формул из элементов классов $S$ и $C$. В статье решена задача о точной оценке модуля тейлоровского коэффициента в этом классе. The central place in the theory of conformal maps is occupied by the solution of extreme problems on classes of single-leaf maps. In the known classes of normalized holomorphic functions S and C, the solution of the "coefficient problem" is associated with obtaining accurate estimates of the modules of the Taylor coefficients of class elements. Similar problems are posed for classes of locally single-leaf mappings. V.G.Sheretov introduced classes of locally conformal mappings generated using integral structural formulas from elements of classes S and C. The article solves the problem of an accurate estimation of the modulus of the Taylor coefficient in this class.


2021 ◽  
Vol 7 (3) ◽  
pp. 11-23
Author(s):  
V. Platonov ◽  
B. Valentinov ◽  
G. Suhih ◽  
M. Volchaeva ◽  
V. Dunaev ◽  
...  

The purpose of the study is to show the expediency of sequentially extracting herbal medicinal raw mate-rials with solvents in order of increasing their polarity, to reveal the nature of the distribution of both different groups of compounds and individual ones in the organic matter of thyme (thyme creeping). Re-sults and their discussion. The results of comparative characterization of the chemical composition and direction of pharmacological action of n-hexane, choroform and ethanol extracts of sequential exhaustive extraction of thyme herb (creeping thyme) obtained using chromatography-mass spectrometry, mass spectra and structural formulas of individual compounds, which were identified in 162 (n-hexane), 101 (chloroform) and 150 (ethanol) extracts. The influence of the nature of the solvent on both the yield of extracts and the structural and group composition of the latter, the features of the structural organization of the extracted compounds have been established, the specificity of the direction of the pharmacologi-cal action of each of the extracts, which made it possible to justify the expediency of successive exhaustive extraction of the initial medicinal raw materials with solvents in ascending order of their polarity.


Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1409
Author(s):  
Gerson A. C. Lopes ◽  
Daniel Atencio ◽  
Javier Ellena ◽  
Marcelo B. Andrade

The roméite-group is part of the pyrochlore-supergroup and comprises cubic oxides of A2B2X6Y formula in which Sb5+ predominates in the B-site. The A and Y main occupants determine different minerals in the group and are important for the discovery of new mineral species. Two different roméite-group mineral samples were analysed by electron microprobe analysis (EMPA), Raman spectroscopy and single-crystal X-ray diffraction (XRD). The first sample is from Prabornaz Mine (locality of the original roméite), Saint Marcel, Valle d’Aosta, Italy, whereas the other one occurs in Kalugeri Hill, Babuna Valley, Jakupica Mountains, Nezilovo, Veles, Macedonia. Sample 1 was identified as fluorcalcioroméite, and sample 2 as hydroxycalcioroméite. Both samples belong to the cubic crystal system, space group Fd3¯m, Z = 8, where a = 10.2881(13) Å, V = 1088.9(4) Å3 for sample 1, and a = 10.2970(13) Å, V = 1091.8(4) Å3 for sample 2. The crystal structure refinements converged to (1) R1 = 0.016, wR2 = 0.042; and (2) R1 = 0.023, wR2 = 0.049. Bond-valence calculations validated the crystal structure refinements determining the correct valences at each crystallographic site. Discrepancies observed in the Sb5+ bond-valence calculations were solved with the use of the proper bond valence parameters. The resulting structural formulas are (Ca1.29Na0.55□0.11Pb0.05)Σ=2.00(Sb1.71Ti0.29)Σ=2.00[O5.73(OH)0.27]Σ=6.00[F0.77O0.21(OH)0.02]Σ=1.00 for sample 1, and (Ca1.30Ce0.51□0.19)Σ=2.00(Sb1.08Ti0.92)Σ=2.00O6.00[(OH)0.61O0.21F0.18]Σ=1.00 for sample 2. The Raman spectra of the samples exhibited the characteristic bands of roméite-group minerals, the most evident corresponding to the Sb-O stretching at around 510 cm−1.


2021 ◽  
Author(s):  
Naruki Yoshikawa ◽  
Kentaro Rikimaru ◽  
Kazuki Yamamoto

Many computer-aided drug design (CADD) methods using deep learning have recently been proposed to explore the chemical space toward novel scaffolds efficiently. However, there is a tradeoff between the ease of generating novel structures and the chemical feasibility of structural formulas. To overcome the limitations of computational filtering, we have implemented a web-based software in which users can share and evaluate computer-generated compounds. The web service is available at https://sanitizer.chemical.space/.


Author(s):  
C. Calderón ◽  
M. M. Castro

AbstractWe give some structural formulas for the family of matrix-valued orthogonal polynomials of size $$2\times 2$$ 2 × 2 introduced by C. Calderón et al. in an earlier work, which are common eigenfunctions of a differential operator of hypergeometric type. Specifically, we give a Rodrigues formula that allows us to write this family of polynomials explicitly in terms of the classical Jacobi polynomials, and write, for the sequence of orthonormal polynomials, the three-term recurrence relation and the Christoffel–Darboux identity. We obtain a Pearson equation, which enables us to prove that the sequence of derivatives of the orthogonal polynomials is also orthogonal, and to compute a Rodrigues formula for these polynomials as well as a matrix-valued differential operator having these polynomials as eigenfunctions. We also describe the second-order differential operators of the algebra associated with the weight matrix.


2021 ◽  
Vol 7 (2) ◽  
pp. 17-22
Author(s):  
V. Platonov ◽  
Aleksandr Hadarcev ◽  
G. Suhih ◽  
M. Volochaeva ◽  
I. Dunaeva

The aim of the study was to perform column adsorption liquid chromatography in order to obtain ethanol eluate, after preliminary sequential elution of ethanol extract with solvents in the order of their polarity: n–hexane, toluene, chloroform, acetone; to study in detail the chemical composition of this eluate by chromatography-mass spectrometry and X-ray fluorescence spectroscopy, with the intensification of compounds determining the composition of eluate, obtaining their masses -spectra, structural formulas, determination of the nature of trace elements. Materials and methods of research. A detailed study of the chemical composition of acetone eluate of ethanol extract of walnuts+ leaves was carried out using column adsorption liquid chromatography, chromato-mass spectrometry and X-ray fluorescence analysis. The results and their discussion. The features of the chemical composition of ethanol eluate of the product of column adsorption liquid chromatography of ethanol extract were studied, the qualitative composition and quantitative content of compounds identified in the first one were established by chromatography-mass spectrometry. Mass spectra and structural formulas were obtained for 31 individual eluate compounds. Ethanol eluate is characterized by the following indicators of structural and group composition (mass. % of eluate): esters of phthalic acid - 52.14, silicon and sulfur-containing compounds, respectively - 20.19 and 6.43, hydrocarbons - 15.38, glycosides - 2.21, alcohols - 1.92, carboxylic acids - 1.07, sterols - 0.89. It is assumed that the pharmacological effect of ethanol eluate is mainly determined by a set of free carboxylic acids, as well as phthalic acid, formed as a result of biochemical and hydrological transesterification of its esters containing compounds, alcohols, glycosides and sterols. Organosilicon compounds during hydrolysis give silica in the size of nanoparticles, which play the role of carriers of the above compounds to various organs of a living organism, as well as drainage of blood vessels from the products of cell metabolism, for example, cholesterol, various fats, etc. A comparative characteristic of the chemical composition of all ethanol extract eluates was carried out, the effectiveness of column adsorption liquid chromatography was shown.


2021 ◽  
Vol 6 (3) ◽  
pp. 259-268
Author(s):  
V. Yu. Kornienko ◽  
M. Yu. Minaev

The paper presents a review of available data about an effect of food additives on the human microbiome and lists the main physiological functions of the gut microbiome. The process of the human microbiome evolution is examined. The relationship between the emergence of a disease and the microbiome composition, as well as the main factors influencing the gut microbiome composition are described. The main food additives used today are listed, their key features are discussed and their structural formulas are given. The information about their effect on the human body through an influence on the microbiome composition is presented. The data on an effect of polysorbate 80, carboxymethylcellulose, sodium sulfite, nisin, potassium sorbate, sodium benzoate, sodium nitrate, essential oils, titanium dioxide and different sweeteners on the microbiome are analyzed. It is explained what microbial communities are suppressed and what communities gain advantages in multiplication when consumers eat food with one or another food additive. The consequences of alterations in the microbiome for the consumer’s body are examined. Conclusions were made about the necessity of additional studies about an effect of food additives on the composition of the human microbiome.


Author(s):  
Burkhan A. Berberov ◽  

Introduction. The riddle which reflects the world outlook of the people is a popular genre in the Karachay-Balkar folklore. However, the richest materials collected over decades have not been studied so far. The present study aims at examining the history and poetics of the Karachay-Balkar riddle drawing on the works of leading foreign and Russian theorists. This has involved i) the discussion of the socio-cultural factors that were conducive to the emergence of the genre, ii) the description of the five principal thematic circles, iii) the analysis of the key structural formulas of the Karachay-Balkar riddle, and iv) the description of the expressive language of the puzzle. Data and research methods. Academic collections, including pre-revolutionary sources, were used as the database for the research, which involved comparative-historical, system-structural, semiotic, textological, and analytical methods. Results. The Karachay-Balkar puzzle may be seen as a bilateral artistic subculture, with one side facing the archetypal invariant, and the other characterized by variability, granted the historical and geographical contexts, the landscape of the North Caucasus, the life, and the culture of the highlanders. The conceptualization of the world in riddles involves five main ontological conceptual spheres: anthropocentric, ethnocultural, natural, cosmogonic, mental, and ethical. The riddle images are most often associated with ethnically marked objects. The distinct character of the Karachay-Balkar riddle is due to frequent use of rhymed poetic forms, verse formulas, proper names, as well as to a wealth of their expressive devices (metaphor, comparison, alliteration, antithesis, sarcasm, and humor). Also, the riddles have a great pedagogical potentiality. Conclusions. The analysis of the Karachay-Balkar riddles resulted in identifying the distinct features in the conceptualizations of the world by the North Caucasian highlanders, as well as in drawing a picture of their values in the material and spiritual spheres.


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