Pub Date : 2023-06-30DOI: 10.31489/2959-0663/2-23-13
Alexander S. Ospennikov, G. Kornilaeva, V. F. Larichev, I. Fedyakina, L. Fu, Zhuo Chen, Yangyang Yang, A. Shibaev, E. Karamov, A. Turgiev, L. Duan, William J. Liu, O. Philippova
The aim of this work was to study virucidal activity against SARS-CoV-2 of several anionic disinfectants, which are antiseptics recommended by the U.S. Environmental Protection Agency (EPA), and to prepare their complexes with hydrophobically modified chitosan active against SARS-CoV-2. Experiments were per-formed using a clinical isolate of SARS-CoV-2 obtained from a patient in 2020. It was shown that sodium dodecyl benzene sulfonate (SDBS) is already active at rather small concentrations (above 2 mM), which completely deactivate the virus. In the same concentration range, sodium caprylate does not show activity; and sodium lactate is active against SARS-CoV-2 only at much higher concentrations (225 mM). The most effective disinfectant — sodium dodecylbenzene sulfonate — was used to prepare complexes with hydrophobically modified chitosan. It was found that such complexes exhibit antiviral activity at very low concentrations (1.9 mM chitosan monomer units and 0.25 mM SDBS), at which the polymer without surfac-tant is not active against SARS-CoV-2.
研究了美国环境保护署(EPA)推荐的几种阴离子消毒剂对SARS-CoV-2的抗病毒活性，并制备了它们与具有抗病毒活性的疏水修饰壳聚糖的配合物。实验使用了2020年从一名患者身上获得的SARS-CoV-2临床分离株。结果表明，十二烷基苯磺酸钠(SDBS)在相当小的浓度(2毫米以上)下已经具有活性，可以完全灭活病毒。在相同浓度范围内，辛酸钠不表现出活性;乳酸钠只有在高得多的浓度(225 mM)下才对SARS-CoV-2有活性。用最有效的消毒剂十二烷基苯磺酸钠与疏水改性壳聚糖制备配合物。研究发现，这种复合物在极低浓度(1.9 mM壳聚糖单体单位和0.25 mM SDBS)下表现出抗病毒活性，在极低浓度下，不含表面活性剂的聚合物对SARS-CoV-2没有活性。
{"title":"Activity against SARS-CoV-2 of Various Anionic Disinfectants and Their Complexes with Hydrophobically Modified Chitosan","authors":"Alexander S. Ospennikov, G. Kornilaeva, V. F. Larichev, I. Fedyakina, L. Fu, Zhuo Chen, Yangyang Yang, A. Shibaev, E. Karamov, A. Turgiev, L. Duan, William J. Liu, O. Philippova","doi":"10.31489/2959-0663/2-23-13","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-13","url":null,"abstract":"The aim of this work was to study virucidal activity against SARS-CoV-2 of several anionic disinfectants, which are antiseptics recommended by the U.S. Environmental Protection Agency (EPA), and to prepare their complexes with hydrophobically modified chitosan active against SARS-CoV-2. Experiments were per-formed using a clinical isolate of SARS-CoV-2 obtained from a patient in 2020. It was shown that sodium dodecyl benzene sulfonate (SDBS) is already active at rather small concentrations (above 2 mM), which completely deactivate the virus. In the same concentration range, sodium caprylate does not show activity; and sodium lactate is active against SARS-CoV-2 only at much higher concentrations (225 mM). The most effective disinfectant — sodium dodecylbenzene sulfonate — was used to prepare complexes with hydrophobically modified chitosan. It was found that such complexes exhibit antiviral activity at very low concentrations (1.9 mM chitosan monomer units and 0.25 mM SDBS), at which the polymer without surfac-tant is not active against SARS-CoV-2.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89928082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-30DOI: 10.31489/2959-0663/2-23-2
Кoblandy M. Turdybekov, P. Zhanymkhanova, G.K. Mukusheva, Y. V. Gatilov
(E)-1-(2-(4-bromobutoxy)-6-hydroxy-4-methoxyphenyl-3-phenylprop-2-en-1-one was synthesized from the pinostrobin molecule. The tetrahydropyran cycle was opened in acetone under heating (50–60 °C) mixtures of components for 16 hours in the presence of 3 moles of K2CO3 and 1,4-dibromobutane. The resulting substance is a yellow powder of the composition C20H21BrO4, mp 83.7–86.6 °C. The structure of the obtained compound was established on the basis of the data of elemental analysis, IR and NMR spectra. As a result of X-ray diffraction analysis, it was found that the hydrogen atoms in the C8=C9 bond take the transconformation. The rotation of the С1…С6 phenyl ring (flat with an accuracy of ±0.008 Å) relative to the С10…С15 cycle (flat with an accuracy of ±0.004 Å) is 14.3°. In the crystal, the molecules are linked by an intramolecular hydrogen bond O4-H....O1 (distances O-H 0.95(8) Ǻ, O····O 2.469(6) Ǻ, H····O 1.58 (8) Ǻ, angle O-H····O 153(7)°). The formation of (E)-1-(2-(4-bromobutoxy)-6-hydroxy-4-methoxy-1-phenylprop-2-en-1-one can be explained by the ease of the retro-Michael reaction of the pyran ring and the subsequent O-alkylation of the resulting chalcone. Carrying out the reaction in the presence of other bases (cesium carbonate, triethylamine) did not lead to success. The starting substance (pinostrobin) was completely converted into oligomeric compounds.
{"title":"Synthesis and Spatial Structure of (E)-1-(2-(4-Bromobutoxy)- 6-Hydroxy-4-Methoxyphenyl-3-Phenylprop-2-en-1-one","authors":"Кoblandy M. Turdybekov, P. Zhanymkhanova, G.K. Mukusheva, Y. V. Gatilov","doi":"10.31489/2959-0663/2-23-2","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-2","url":null,"abstract":"(E)-1-(2-(4-bromobutoxy)-6-hydroxy-4-methoxyphenyl-3-phenylprop-2-en-1-one was synthesized from the pinostrobin molecule. The tetrahydropyran cycle was opened in acetone under heating (50–60 °C) mixtures of components for 16 hours in the presence of 3 moles of K2CO3 and 1,4-dibromobutane. The resulting substance is a yellow powder of the composition C20H21BrO4, mp 83.7–86.6 °C. The structure of the obtained compound was established on the basis of the data of elemental analysis, IR and NMR spectra. As a result of X-ray diffraction analysis, it was found that the hydrogen atoms in the C8=C9 bond take the transconformation. The rotation of the С1…С6 phenyl ring (flat with an accuracy of ±0.008 Å) relative to the С10…С15 cycle (flat with an accuracy of ±0.004 Å) is 14.3°. In the crystal, the molecules are linked by an intramolecular hydrogen bond O4-H....O1 (distances O-H 0.95(8) Ǻ, O····O 2.469(6) Ǻ, H····O 1.58 (8) Ǻ, angle O-H····O 153(7)°). The formation of (E)-1-(2-(4-bromobutoxy)-6-hydroxy-4-methoxy-1-phenylprop-2-en-1-one can be explained by the ease of the retro-Michael reaction of the pyran ring and the subsequent O-alkylation of the resulting chalcone. Carrying out the reaction in the presence of other bases (cesium carbonate, triethylamine) did not lead to success. The starting substance (pinostrobin) was completely converted into oligomeric compounds.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"95 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83405467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-30DOI: 10.31489/2959-0663/2-23-14
Zhanar S. Akhmetkarimova, G. Kudaibergen, Guldarigash K. Kaukabaeva, S. Abeldenov, A. Rysbek
Hydrogels used in biomedical applications, particularly for soft tissue treatment and regeneration, should have favorable mechanical properties and biocompatibility. Alginate hydrogels are suitable for developing wound dressings with desirable porosity, facilitating effective gas and vapor exchange necessary for wound healing. In this study, we present the synthesis and characterization of photocrosslinked hydrogels based on sodium alginate allyl glycidyl ether (SA-AGE). The composition and structure of the synthesized macromers were confirmed using nuclear magnetic resonance spectroscopy (1H-NMR), while scanning electron microscopy (SEM) revealed the presence of pores ranging in size from 5–32 μm. The UV light polymerization of SA-AGE hydrogel using the photoinitiator I295 was achieved within 60 minutes. The absorption of silver particles and the drug cefepime was determined through titration and UV-spectroscopy, indicating that the optimal concentration was 1 %. The antibacterial activity of the hydrogels loaded with silver nanoparticles and cefepime was evaluated against gram-negative (Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) strains. Cytotoxicity of the hydrogels was assessed using the MTT assay with rat ADMSC cells, and the cell survival rate in the presence of the hydrogels was above 80 %, indicating their noncytotoxic nature.
{"title":"Thiol-Ene Click Synthesis of Alginate Hydrogels Loaded with Silver Nanoparticles and Cefepime","authors":"Zhanar S. Akhmetkarimova, G. Kudaibergen, Guldarigash K. Kaukabaeva, S. Abeldenov, A. Rysbek","doi":"10.31489/2959-0663/2-23-14","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-14","url":null,"abstract":"Hydrogels used in biomedical applications, particularly for soft tissue treatment and regeneration, should have favorable mechanical properties and biocompatibility. Alginate hydrogels are suitable for developing wound dressings with desirable porosity, facilitating effective gas and vapor exchange necessary for wound healing. In this study, we present the synthesis and characterization of photocrosslinked hydrogels based on sodium alginate allyl glycidyl ether (SA-AGE). The composition and structure of the synthesized macromers were confirmed using nuclear magnetic resonance spectroscopy (1H-NMR), while scanning electron microscopy (SEM) revealed the presence of pores ranging in size from 5–32 μm. The UV light polymerization of SA-AGE hydrogel using the photoinitiator I295 was achieved within 60 minutes. The absorption of silver particles and the drug cefepime was determined through titration and UV-spectroscopy, indicating that the optimal concentration was 1 %. The antibacterial activity of the hydrogels loaded with silver nanoparticles and cefepime was evaluated against gram-negative (Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) strains. Cytotoxicity of the hydrogels was assessed using the MTT assay with rat ADMSC cells, and the cell survival rate in the presence of the hydrogels was above 80 %, indicating their noncytotoxic nature.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83978381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-30DOI: 10.31489/2959-0663/2-23-16
Mukhlisa Q. Saidmuhamedova, Islom H. Turdiqulov, A. Atakhanov, Nurbek Sh. Ashurov, M. Abdurazakov, S. Rashidova, O. Surov
Composite materials filled with cellulose particles (microcrystalline cellulose and nanocellulose) have good prospects for use in various fields. Microcrystalline cellulose (MCC) and nanocellulose (NC) were isolated by chemical and physical methods and investigated. Composite materials based on polyethylene (PE) were obtained using MCC and NC as fillers (5–20 wt.%) and maleic anhydride grafted low molecular weight polyethylene (MA-g-LMPE) as a compatibilizer. The structure and morphology of the composites and fillers were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, thermal analysis (TA), transmission electron microscopy (TEM), atomic force microscopy (AFM), and the strength properties were determined by tensile testing. An increase in the crystallinity index and mechanical strength of composites at low filler contents (up to 5 wt.%) was revealed. The size of the cellulose particles significantly affects the structure and properties of composites. Although the general picture of the effect of fillers on the crystalline structure and mechanical properties is similar, the addition of NC had a greater effect than МСС. The results of this study showed the possibility of using MCC and NC as reinforcement materials in composites, and they have biodegradable properties.
{"title":"Biodegradable Polyethylene-Based Composites Filled with Cellulose Micro- and Nanoparticles","authors":"Mukhlisa Q. Saidmuhamedova, Islom H. Turdiqulov, A. Atakhanov, Nurbek Sh. Ashurov, M. Abdurazakov, S. Rashidova, O. Surov","doi":"10.31489/2959-0663/2-23-16","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-16","url":null,"abstract":"Composite materials filled with cellulose particles (microcrystalline cellulose and nanocellulose) have good prospects for use in various fields. Microcrystalline cellulose (MCC) and nanocellulose (NC) were isolated by chemical and physical methods and investigated. Composite materials based on polyethylene (PE) were obtained using MCC and NC as fillers (5–20 wt.%) and maleic anhydride grafted low molecular weight polyethylene (MA-g-LMPE) as a compatibilizer. The structure and morphology of the composites and fillers were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, thermal analysis (TA), transmission electron microscopy (TEM), atomic force microscopy (AFM), and the strength properties were determined by tensile testing. An increase in the crystallinity index and mechanical strength of composites at low filler contents (up to 5 wt.%) was revealed. The size of the cellulose particles significantly affects the structure and properties of composites. Although the general picture of the effect of fillers on the crystalline structure and mechanical properties is similar, the addition of NC had a greater effect than МСС. The results of this study showed the possibility of using MCC and NC as reinforcement materials in composites, and they have biodegradable properties.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82715366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.31489/2959-0663/1-23-2
S. Tulasi, P. Sumalatha, N. Rani, Pavani Peddi
The goal of the present study was to synthesize the nanoparticles using green methodology with the use of the aqueous plant extract of S. swietenioides. The copper oxide nanoparticle have been synthesised using aqueous root extract of S. swietenioides as a green reducing agent and copper sulfate as source of the metal ions. For-mation of the nanoparticles in the reaction mixture was preliminary confirmed by the UV-Vis spectroscopy method. The FT-IR analysis of the synthesised nanoparticles shows the involvement of various bioactive functional groups in the formation of nanoparticles. The UV–Vis absorption spectra indicates the characteris-tic maximum absorption peak at a wavelength of 340 nm. This confirms the formation of nano-sized copper particles. The SEM analysis of the synthesised copper oxide nanoparticles confirms that the particles have mostly spherical shape with rough surfaces and the size of 21-43 nm. The copper nanoparticles in the media of the aqueous root extract of S swietenioides have been studied for their applications in the photo catalytic reduction of pollutant dyes and metals. The synthesized nanoparticles have been characterized and it was proved that the particles were nano-sized and contained high metal percentage.
{"title":"Green Synthesis, Characterisation and Environmental Application of Copper Oxide Nanoparticle obtained Using Aqueous Extract of Schrebera Swietenioides Roxb.","authors":"S. Tulasi, P. Sumalatha, N. Rani, Pavani Peddi","doi":"10.31489/2959-0663/1-23-2","DOIUrl":"https://doi.org/10.31489/2959-0663/1-23-2","url":null,"abstract":"The goal of the present study was to synthesize the nanoparticles using green methodology with the use of the aqueous plant extract of S. swietenioides. The copper oxide nanoparticle have been synthesised using aqueous root extract of S. swietenioides as a green reducing agent and copper sulfate as source of the metal ions. For-mation of the nanoparticles in the reaction mixture was preliminary confirmed by the UV-Vis spectroscopy method. The FT-IR analysis of the synthesised nanoparticles shows the involvement of various bioactive functional groups in the formation of nanoparticles. The UV–Vis absorption spectra indicates the characteris-tic maximum absorption peak at a wavelength of 340 nm. This confirms the formation of nano-sized copper particles. The SEM analysis of the synthesised copper oxide nanoparticles confirms that the particles have mostly spherical shape with rough surfaces and the size of 21-43 nm. The copper nanoparticles in the media of the aqueous root extract of S swietenioides have been studied for their applications in the photo catalytic reduction of pollutant dyes and metals. The synthesized nanoparticles have been characterized and it was proved that the particles were nano-sized and contained high metal percentage.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78622393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.31489/2959-0663/2-23-3
T. Chouchane, Atmane Boukari, Ouahida Khireddine, S. Chibani, Sabiha Chouchane
The copper adsorption by blast furnace slag (BFS) in an aqueous medium was considered based on the influ-encing parameters, namely the agitation speed, pH, temperature, the particle size of the solid, and the initial concentration. Physicochemical studies have shown that BFS is consisted mainly from SiO2, CaO, Al2O3, and MgO with a specific surface area of 238 m2/g. Under the optimum parameters, the maximum adsorption amount at equilibrium (140 min) corresponds to 45.16 mg/g. Exploration of adsorption isotherms revealed that the Langmuir model is more consistent with the experimental data. The values of the Freundlich (n) and Langmuir (RL) parameters indicate that the adsorption is favorable. On the other hand, the values of Temkin (bt) and Redlich-Peterson (g) parameters show that adsorption is physical. Pseudo-second order of the adsorp-tion process was confirmed using a kinetic study. Moreover, the diffusional study specified that the transfer of copper from the solution to BFS is successively controlled by external and intraparticle diffusion. The thermodynamic parameters showed that the adsorption of Cu(II) on BFS was feasible, spontaneous, exother-mic, and less entropic. The desorption phenomenon has revealed that BFS can be reused for three consecutive cycles.
{"title":"Cu(II) Removal from Aqueous Medium Using Blast Furnace Slag (BFS) as an Effective Adsorbent","authors":"T. Chouchane, Atmane Boukari, Ouahida Khireddine, S. Chibani, Sabiha Chouchane","doi":"10.31489/2959-0663/2-23-3","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-3","url":null,"abstract":"The copper adsorption by blast furnace slag (BFS) in an aqueous medium was considered based on the influ-encing parameters, namely the agitation speed, pH, temperature, the particle size of the solid, and the initial concentration. Physicochemical studies have shown that BFS is consisted mainly from SiO2, CaO, Al2O3, and MgO with a specific surface area of 238 m2/g. Under the optimum parameters, the maximum adsorption amount at equilibrium (140 min) corresponds to 45.16 mg/g. Exploration of adsorption isotherms revealed that the Langmuir model is more consistent with the experimental data. The values of the Freundlich (n) and Langmuir (RL) parameters indicate that the adsorption is favorable. On the other hand, the values of Temkin (bt) and Redlich-Peterson (g) parameters show that adsorption is physical. Pseudo-second order of the adsorp-tion process was confirmed using a kinetic study. Moreover, the diffusional study specified that the transfer of copper from the solution to BFS is successively controlled by external and intraparticle diffusion. The thermodynamic parameters showed that the adsorption of Cu(II) on BFS was feasible, spontaneous, exother-mic, and less entropic. The desorption phenomenon has revealed that BFS can be reused for three consecutive cycles.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79150033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.31489/2959-0663/3-23-11
Lenara I. Valiulina, Kirill Khoroshkin, V. Cherepanov, R. Valiev
Quantum-chemical calculations of the magnetic properties (magnetically induced ring-current strength, magnetizability) of even- and odd-number cyclo[n]carbons (n = 10–34) were carried out. The total energy of the studied molecules as a function of the external magnetic field was found for the first time. The obtained dependences predict correctly the magnetic nature of cyclo[n]carbons. For even-number aromatic cyclo[n]carbons the energy of the system increases with increasing magnetic field, while for antiaromatic sys-tems, the energy decreases. Such behavior indicates that aromatic even-number cyclo[n]carbons (n = 4k+2) are diamagnetic, whereas antiaromatic even-number cyclo[n]carbons (n = 4k) are paramagnetic. These results are confirmed by the previously calculated average magnetizability values. In the case of odd-number cyclo[n]carbons, all structures except C13 are diamagnetic. Antiaromatic C13 is paramagnetic according to average magnetizability calculations. It was shown that nonaromatic cyclo[n]carbons (n = 28–34) at high magnetic fields (B > 300 T) possess a nonlinear effect of the increase in the energy of the system with in-creasing magnetic field. This effect can be observed experimentally in NMR spectra at a magnetic field great-er than 300 T.The performed calculations demonstrate that the HF method correctly predicts the magnetic and aromatic properties of cyclo[n]carbons (n = 10–34).
{"title":"Magnetic Properties of Cyclo[n]Carbons (n = 10–34)","authors":"Lenara I. Valiulina, Kirill Khoroshkin, V. Cherepanov, R. Valiev","doi":"10.31489/2959-0663/3-23-11","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-11","url":null,"abstract":"Quantum-chemical calculations of the magnetic properties (magnetically induced ring-current strength, magnetizability) of even- and odd-number cyclo[n]carbons (n = 10–34) were carried out. The total energy of the studied molecules as a function of the external magnetic field was found for the first time. The obtained dependences predict correctly the magnetic nature of cyclo[n]carbons. For even-number aromatic cyclo[n]carbons the energy of the system increases with increasing magnetic field, while for antiaromatic sys-tems, the energy decreases. Such behavior indicates that aromatic even-number cyclo[n]carbons (n = 4k+2) are diamagnetic, whereas antiaromatic even-number cyclo[n]carbons (n = 4k) are paramagnetic. These results are confirmed by the previously calculated average magnetizability values. In the case of odd-number cyclo[n]carbons, all structures except C13 are diamagnetic. Antiaromatic C13 is paramagnetic according to average magnetizability calculations. It was shown that nonaromatic cyclo[n]carbons (n = 28–34) at high magnetic fields (B > 300 T) possess a nonlinear effect of the increase in the energy of the system with in-creasing magnetic field. This effect can be observed experimentally in NMR spectra at a magnetic field great-er than 300 T.The performed calculations demonstrate that the HF method correctly predicts the magnetic and aromatic properties of cyclo[n]carbons (n = 10–34).","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85331428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.31489/2959-0663/1-23-1
Кoblandy M. Turdybekov, B. B. Rakhimova, Almagul S. Makhmutova, Y. V. Gatilov, S. Adekenov
The article presents the results of a chemical study of semi-dry wormwood (Artemisia semiarida), an endemic plant of Kazakhstan. The amount of extractive substances was obtained by extraction with chloroform from air-dried crushed above-ground part of the plant collected in the vegetative phase. The compound was isolat-ed using a column chromatography method. Silica gel of the KSK brand was used with the ratio of the sum of substances – carrier = 1:10. When the column was eluted with a 13:7 petroleum ether – ethyl acetate mixture, a yellow crystalline substance of the composition C18H16O7 with m.p. 234–237 °C was obtained (recrystalli-zation from ethyl acetate). The structure of the obtained compound (5,7-dihydroxy-6,3′,4′-trimethoxyflavone or eupatilin) was established by analysis of IR and NMR spectra. The spatial structure of eupatilin was de-termined by X-ray diffraction. In the crystal structure of 5,7-dihydroxy-6,3′,4′-trimethoxyflavone the rotation of the phenyl ring relative to the main framework (chromene ring) was found to be only 4.1°. Four conform-ers with different rotations of the phenyl ring (the torsional angles of O1C2C1′C2′ are 30, 140, 210, and 320°, respectively) and small energy barriers (about 8.4 kJ/mol) can be realized in the free state of the molecule.
{"title":"Isolation and Spatial Structure of 5,7-Dihydroxy-6,3′,4′-Trimethoxyflavone","authors":"Кoblandy M. Turdybekov, B. B. Rakhimova, Almagul S. Makhmutova, Y. V. Gatilov, S. Adekenov","doi":"10.31489/2959-0663/1-23-1","DOIUrl":"https://doi.org/10.31489/2959-0663/1-23-1","url":null,"abstract":"The article presents the results of a chemical study of semi-dry wormwood (Artemisia semiarida), an endemic plant of Kazakhstan. The amount of extractive substances was obtained by extraction with chloroform from air-dried crushed above-ground part of the plant collected in the vegetative phase. The compound was isolat-ed using a column chromatography method. Silica gel of the KSK brand was used with the ratio of the sum of substances – carrier = 1:10. When the column was eluted with a 13:7 petroleum ether – ethyl acetate mixture, a yellow crystalline substance of the composition C18H16O7 with m.p. 234–237 °C was obtained (recrystalli-zation from ethyl acetate). The structure of the obtained compound (5,7-dihydroxy-6,3′,4′-trimethoxyflavone or eupatilin) was established by analysis of IR and NMR spectra. The spatial structure of eupatilin was de-termined by X-ray diffraction. In the crystal structure of 5,7-dihydroxy-6,3′,4′-trimethoxyflavone the rotation of the phenyl ring relative to the main framework (chromene ring) was found to be only 4.1°. Four conform-ers with different rotations of the phenyl ring (the torsional angles of O1C2C1′C2′ are 30, 140, 210, and 320°, respectively) and small energy barriers (about 8.4 kJ/mol) can be realized in the free state of the molecule.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"140 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80442442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.31489/2959-0663/1-23-7
U. Nagababu, D. Sujatha, Uppalapati Jyothi, Manikyala Rao Vissa, B. S. Kumar
Ubrogepant is a medical drug prescribed for the treatment of migraine in adults. Literature analysis has shown, that no suitable analytical method has been published to date for the quantification of impurities of Ubrogepant. Therefore, this study aims to develop a simple and sensitive stability indicating HPLC method for quantifying Ubrogepant and its impurities 1 and 2. The optimized and best separation was achieved using ProntoSIL ODS C18 (250×4.6 mm; 5 μ id) column as stationary phase, phosphate buffer (pH 4.5) and methanol in 65:35 (v/v) at 1.0 mL/min as mobile phase and 246 nm as detector wavelength. The method reports 0.015 μg/mL and 0.05 μg/mL as limit of detection (LOD) and limit of quantitation (LOQ) for both impurities. This proves that the method has sufficient levels of sensitivity to detect impurities. The method passes all validation parameters as recommended, confirming that the method is valid. The method can show very less % degradation in various stress tests such as acid, base, peroxide, thermal and UV light conditions, and can efficiently resolve different compounds generation during stress exposure, as well as its known impurities prove the stability indicating nature of the method. Based on the experimental findings, it was shown that the method is significantly useful for the routine analysis of Ubrogepant and its impurities 1 and 2.
{"title":"Validated Stability Indicating HPLC Method for the Quantification of Process Related Impurities of Ubrogepant in Pharmaceutical Formulations","authors":"U. Nagababu, D. Sujatha, Uppalapati Jyothi, Manikyala Rao Vissa, B. S. Kumar","doi":"10.31489/2959-0663/1-23-7","DOIUrl":"https://doi.org/10.31489/2959-0663/1-23-7","url":null,"abstract":"Ubrogepant is a medical drug prescribed for the treatment of migraine in adults. Literature analysis has shown, that no suitable analytical method has been published to date for the quantification of impurities of Ubrogepant. Therefore, this study aims to develop a simple and sensitive stability indicating HPLC method for quantifying Ubrogepant and its impurities 1 and 2. The optimized and best separation was achieved using ProntoSIL ODS C18 (250×4.6 mm; 5 μ id) column as stationary phase, phosphate buffer (pH 4.5) and methanol in 65:35 (v/v) at 1.0 mL/min as mobile phase and 246 nm as detector wavelength. The method reports 0.015 μg/mL and 0.05 μg/mL as limit of detection (LOD) and limit of quantitation (LOQ) for both impurities. This proves that the method has sufficient levels of sensitivity to detect impurities. The method passes all validation parameters as recommended, confirming that the method is valid. The method can show very less % degradation in various stress tests such as acid, base, peroxide, thermal and UV light conditions, and can efficiently resolve different compounds generation during stress exposure, as well as its known impurities prove the stability indicating nature of the method. Based on the experimental findings, it was shown that the method is significantly useful for the routine analysis of Ubrogepant and its impurities 1 and 2.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76361268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.31489/2959-0663/2-23-7
Aldana Galiyeva, Y. Tazhbayev, Nazgul A. Yessentayeva, A.Т. Daribay, Dias T. Marsel, D. Sadyrbekov, L. Zhaparova, Zh.T. Arystanova
Polyethylene glycol (PEG) is widely used in nanomedicine to extend the circulation time of a drug in the blood and increase drug efficacy. Conjugation by attaching polyethylene glycol to an albumin macromolecule and nanoparticles is a well-established technique known as PEGylation. The aim of this research was to pre-pare and evaluate serum stable long circulating PEG-albumin-isoniazid nanoparticles for the treatment of Mycobacterium tuberculosis which can improve its therapeutic effect by increasing its permeability, solubili-ty and accumulation in aveolar macrophages. For the first time, PEGylated BSA nanoparticles loaded with isoniazid were synthesized by desolvation using urea and cysteine as denaturing and stabilizing agents. Na-noparticles with an average size of up to 300 nm were obtained by varying the PEG concentration. The polydispersity index of all particle charges was less than 0.1, indicating monodisperse size. The ζ potential values indicate sufficient physical stability of the nanoparticles. SEM images showed that the particles were spherical in shape. The TGA and DSC results obtained confirm that drug loading does not affect the structure of the polymer. Based on FT-IR studies, the absence of chemical interactions between PEGylated BSA nano-particles and isoniazid was established. In in vitro release studies, the nanoparticles were demonstrated to have a prologue release.
{"title":"PEGylation of Albumin Nanoparticles Immobilized with the Anti-Tuberculosis Drug “Isoniazid”","authors":"Aldana Galiyeva, Y. Tazhbayev, Nazgul A. Yessentayeva, A.Т. Daribay, Dias T. Marsel, D. Sadyrbekov, L. Zhaparova, Zh.T. Arystanova","doi":"10.31489/2959-0663/2-23-7","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-7","url":null,"abstract":"Polyethylene glycol (PEG) is widely used in nanomedicine to extend the circulation time of a drug in the blood and increase drug efficacy. Conjugation by attaching polyethylene glycol to an albumin macromolecule and nanoparticles is a well-established technique known as PEGylation. The aim of this research was to pre-pare and evaluate serum stable long circulating PEG-albumin-isoniazid nanoparticles for the treatment of Mycobacterium tuberculosis which can improve its therapeutic effect by increasing its permeability, solubili-ty and accumulation in aveolar macrophages. For the first time, PEGylated BSA nanoparticles loaded with isoniazid were synthesized by desolvation using urea and cysteine as denaturing and stabilizing agents. Na-noparticles with an average size of up to 300 nm were obtained by varying the PEG concentration. The polydispersity index of all particle charges was less than 0.1, indicating monodisperse size. The ζ potential values indicate sufficient physical stability of the nanoparticles. SEM images showed that the particles were spherical in shape. The TGA and DSC results obtained confirm that drug loading does not affect the structure of the polymer. Based on FT-IR studies, the absence of chemical interactions between PEGylated BSA nano-particles and isoniazid was established. In in vitro release studies, the nanoparticles were demonstrated to have a prologue release.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81462134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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