The phase equilibria in the ternary La2О3–Lu2O3–Er2O3 system at 1250°C were studied by X-ray diffraction, and electron microscopy in the overall concentration range. At 1250°С in the La2О3–Lu2O3–Er2O3 system solution fields are formed based on cubic (C) modification of Lu2O3(Er2O3), hexagonal (A) modification of La2O3, as well as ordered phase structure perovskite-type LaLuO3 (LaErO3) (R). The isothermal section of the La2O3–Lu2O3–Er2O3 phase diagram at 1250°C has shown the three one-phase fields (A-La2O3, R, C-Lu2O3(Er2O3)) corresponding to solid solutions based on starting components and two dual-phase fields (C+R, A+R) between them. The refined lattice parameters of the unit cells for solid solutions and microstructures of the definite field of compositions for the systems solid were determined.
通过 X 射线衍射和电子显微镜研究了 1250°C 时三元 La2О3-Lu2O3-Er2O3 体系在总体浓度范围内的相平衡。1250°С时，在La2О3-Lu2O3-Er2O3体系中形成了基于立方（C）修饰的Lu2O3（Er2O3）、六方（A）修饰的La2O3以及有序相结构的透辉石型LaLuO3（LaErO3）（R）的溶液场。1250°C 时 La2O3-Lu2O3-Er2O3 相图的等温截面显示了三个单相场（A-La2O3、R、C-Lu2O3(Er2O3)），对应于基于起始组分的固溶体，以及它们之间的两个双相场（C+R、A+R）。确定了固溶体单位晶胞的细化晶格参数和系统固态成分定域的微观结构。
{"title":"Isothermal section of the La2O3-Lu2O33-Er2O3 ternary phase diagram at 1250°С","authors":"O. Chudinovych","doi":"10.19261/cjm.2023.1081","DOIUrl":"https://doi.org/10.19261/cjm.2023.1081","url":null,"abstract":"The phase equilibria in the ternary La2О3–Lu2O3–Er2O3 system at 1250°C were studied by X-ray diffraction, and electron microscopy in the overall concentration range. At 1250°С in the La2О3–Lu2O3–Er2O3 system solution fields are formed based on cubic (C) modification of Lu2O3(Er2O3), hexagonal (A) modification of La2O3, as well as ordered phase structure perovskite-type LaLuO3 (LaErO3) (R). The isothermal section of the La2O3–Lu2O3–Er2O3 phase diagram at 1250°C has shown the three one-phase fields (A-La2O3, R, C-Lu2O3(Er2O3)) corresponding to solid solutions based on starting components and two dual-phase fields (C+R, A+R) between them. The refined lattice parameters of the unit cells for solid solutions and microstructures of the definite field of compositions for the systems solid were determined.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":"41 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139188669","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}
The rheological behavior of some mayonnaise varieties prepared from liquid egg yolks, fresh or frozen, whose oily phase is made up of mixtures of sesame oil and rapeseed oil was studied in the current paper. The study examined the influence of the freezing time of the egg yolk, of the ratio between the two types of oil, as well as of the storage time, on the rheological parameters (apparent viscosity, consistency coefficient, flow behavior index). It has been shown that all types of mayonnaise present non-Newtonian behavior (pseudoplastic), because the values of the flow behavior index established from the specific mathematical models (Ostwald de Waele and Herschel-Bulkley) are sub-unit, and the apparent viscosity decreases with the increase of the shear rate. Mayonnaises prepared from frozen egg yolks and those with an oily phase in which sesame oil is predominant, have a higher consistency. The oxidation stability was evaluated by determining the acid values, which increase slightly with the freezing time of the egg yolk and with the amount of sesame oil in the oily phase. From the color tests carried out in the CIELAB color space, the characteristic parameters L*, a* and b* were determined and the lightness of the mayonnaise was assessed.
本文研究了以新鲜或冷冻液态蛋黄为原料，油相由芝麻油和菜籽油混合而成的几种蛋黄酱的流变特性。本研究考察了蛋黄的冷冻时间、两种油的配比以及储存时间对蛋黄流变参数(表观粘度、稠度系数、流动性能指标)的影响。根据特定的数学模型(Ostwald de Waele和Herschel-Bulkley)建立的流动性能指数值为亚单位，表观粘度随剪切速率的增加而降低，因此所有类型的蛋黄酱都表现出非牛顿行为(假塑性)。用冷冻蛋黄和以芝麻油为主的油性蛋黄制作的蛋黄酱具有更高的稠度。通过测定酸值来评价氧化稳定性，酸值随蛋黄冷冻时间的延长和油相中芝麻油的添加量的增加而略有增加。通过在CIELAB色彩空间中进行的色彩测试，确定了特征参数L*、a*和b*，并评估了蛋黄酱的亮度。
{"title":"Mayonnaises from fresh or frozen egg yolk with rapeseed and sesame oils -the influence of egg yolk freezing and storage time and oils ratio","authors":"A. Tamás, Sabina Nitu, S. Popa, M. Padure","doi":"10.19261/cjm.2023.1060","DOIUrl":"https://doi.org/10.19261/cjm.2023.1060","url":null,"abstract":"The rheological behavior of some mayonnaise varieties prepared from liquid egg yolks, fresh or frozen, whose oily phase is made up of mixtures of sesame oil and rapeseed oil was studied in the current paper. The study examined the influence of the freezing time of the egg yolk, of the ratio between the two types of oil, as well as of the storage time, on the rheological parameters (apparent viscosity, consistency coefficient, flow behavior index). It has been shown that all types of mayonnaise present non-Newtonian behavior (pseudoplastic), because the values of the flow behavior index established from the specific mathematical models (Ostwald de Waele and Herschel-Bulkley) are sub-unit, and the apparent viscosity decreases with the increase of the shear rate. Mayonnaises prepared from frozen egg yolks and those with an oily phase in which sesame oil is predominant, have a higher consistency. The oxidation stability was evaluated by determining the acid values, which increase slightly with the freezing time of the egg yolk and with the amount of sesame oil in the oily phase. From the color tests carried out in the CIELAB color space, the characteristic parameters L*, a* and b* were determined and the lightness of the mayonnaise was assessed.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":"7 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80142518","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}
M. Mikuriya, S. Kawauchi, R. Mitsuhashi, M. Tsuboi, M. Handa
A heterometal assembled complex of tetrakis(μ-butanoato)diruthenium(II,III) and tetracyanidoaurate(III) [RuIIRuIII(n-C3H7COO)4AuIII(CN)4]n was synthesized and characterized by the elemental analysis and infrared spectroscopy. The single-crystal X-ray structure analysis revealed that the complex consists of zigzag chain molecules of alternating arrangement of the Ru2(n-C3H7COO)4+ and Au(CN)4– units with cis-bridging mode of the Au(CN)4– units. The temperature dependence of the magnetic susceptibility data (4.5—300 K) showed that the magnetic interaction between the dinuclear RuIIRuIII units (S= 3/2) is negligibly small with a zero-field splitting parameter D value of 60 cm-1.
{"title":"Geometrical isomerism in Ru2Au heterometal assembly: cis-linking of tetracyanidoaurate to tetrakis(μ-butanoato)diruthenium","authors":"M. Mikuriya, S. Kawauchi, R. Mitsuhashi, M. Tsuboi, M. Handa","doi":"10.19261/cjm.2023.1059","DOIUrl":"https://doi.org/10.19261/cjm.2023.1059","url":null,"abstract":"A heterometal assembled complex of tetrakis(μ-butanoato)diruthenium(II,III) and tetracyanidoaurate(III) [RuIIRuIII(n-C3H7COO)4AuIII(CN)4]n was synthesized and characterized by the elemental analysis and infrared spectroscopy. The single-crystal X-ray structure analysis revealed that the complex consists of zigzag chain molecules of alternating arrangement of the Ru2(n-C3H7COO)4+ and Au(CN)4– units with cis-bridging mode of the Au(CN)4– units. The temperature dependence of the magnetic susceptibility data (4.5—300 K) showed that the magnetic interaction between the dinuclear RuIIRuIII units (S= 3/2) is negligibly small with a zero-field splitting parameter D value of 60 cm-1.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":"45 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80968933","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}
S. Pogrebnoi, Nicolai Eremia, Dmitri Bilan, Lucian Lupascu, N. Bolocan, G. Duca, Svetlana Armasu, D. Terteac, Vitalie Cebanu, Serghei Tincu, Alexandru Znagovan, Iulia Neicovcena, Olga Coseleva, V. Slanina, F. Macaev
The chemical composition, antioxidant and antimicrobial activity of propolis ethanolic and water-ethanolic extracts from the central zone of Moldova have been investigated by GC-MS and liquid chromatography. There were found 20 amino acids, of which the most abundant are glutamic acid, alanine, leucine and isoleucine. The main constituents of the alcoholic extract are pinocembrin, n-heptacosan and naringenin. The aqueous-alcoholic extract was characterized by the content of sakuranin, 4-methoxy sakuranetin, caryophylline oxide, isocaryophylline oxide, trans-longipinocarveol. The propolis extracts exhibited strong antioxidant (53.7 mg ascorbic acid eq./g extract or 113.4 mg Trolox eq./g extract and 87.5 mg ascorbic acid eq./g extract or 162 mg Trolox eq./g extract for ethanol, and water-ethanol extract, respectively) and antimicrobial activity (from 0.0055 up to 0.07%), suggesting their potential as natural agents for therapeutic use.
{"title":"Characterization of propolis from Moldova's central region: chemical composition, antioxidant and antimicrobial properties","authors":"S. Pogrebnoi, Nicolai Eremia, Dmitri Bilan, Lucian Lupascu, N. Bolocan, G. Duca, Svetlana Armasu, D. Terteac, Vitalie Cebanu, Serghei Tincu, Alexandru Znagovan, Iulia Neicovcena, Olga Coseleva, V. Slanina, F. Macaev","doi":"10.19261/cjm.2023.924","DOIUrl":"https://doi.org/10.19261/cjm.2023.924","url":null,"abstract":"The chemical composition, antioxidant and antimicrobial activity of propolis ethanolic and water-ethanolic extracts from the central zone of Moldova have been investigated by GC-MS and liquid chromatography. There were found 20 amino acids, of which the most abundant are glutamic acid, alanine, leucine and isoleucine. The main constituents of the alcoholic extract are pinocembrin, n-heptacosan and naringenin. The aqueous-alcoholic extract was characterized by the content of sakuranin, 4-methoxy sakuranetin, caryophylline oxide, isocaryophylline oxide, trans-longipinocarveol. The propolis extracts exhibited strong antioxidant (53.7 mg ascorbic acid eq./g extract or 113.4 mg Trolox eq./g extract and 87.5 mg ascorbic acid eq./g extract or 162 mg Trolox eq./g extract for ethanol, and water-ethanol extract, respectively) and antimicrobial activity (from 0.0055 up to 0.07%), suggesting their potential as natural agents for therapeutic use.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":"26 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76025698","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}
Nitrite ion, a characteristic pollutant, can be removed from water by reverse osmosis, distillation, or ion exchange resin. In this study, we removed it by using ZnO and CeO2 nanoparticles. First, zinc hydroxide and cerium hydroxide were prepared by the hydrothermal method and heated at 90°C to dry. Second, they were annealed at 400°C to produce nanoparticles of ZnO and CeO2, respectively. The obtained samples were characterized by X-ray diffraction to ascertain their structure and chemical composition. The surface morphology analysis of the nanoparticles was performed using scanning electron microscopy. Atomic force microscopy was employed to characterize the imaging surface and ascertain the surface roughness. The functional groups present at the surface of the nanoparticles were investigated using the Fourier transform infrared spectroscopy method. The optical properties of these particles were investigated using the UV-visible spectroscopy. Further, the produced nanoparticles were used to adsorb NO2- ions from aqueous solutions. The results showed that the nanoparticles which were heated at 90°C (hydroxide forms) presented a higher activity for nitrite ions removal than those that were heated at 400°C (oxide forms). This may be related to nitrite ions preferential adsorption to hydroxide forms rather than to oxide forms; in both cases (90°C and 400°C), zinc oxide nanoparticles presented higher nitrite removal activity.
{"title":"Synthesis and characterization of zinc oxide and cerium dioxide nanoparticles with possible application for nitrite ions removal in waters","authors":"Zainab Abdul-Zahra, R. Rasheed","doi":"10.19261/cjm.2023.1027","DOIUrl":"https://doi.org/10.19261/cjm.2023.1027","url":null,"abstract":"Nitrite ion, a characteristic pollutant, can be removed from water by reverse osmosis, distillation, or ion exchange resin. In this study, we removed it by using ZnO and CeO2 nanoparticles. First, zinc hydroxide and cerium hydroxide were prepared by the hydrothermal method and heated at 90°C to dry. Second, they were annealed at 400°C to produce nanoparticles of ZnO and CeO2, respectively. The obtained samples were characterized by X-ray diffraction to ascertain their structure and chemical composition. The surface morphology analysis of the nanoparticles was performed using scanning electron microscopy. Atomic force microscopy was employed to characterize the imaging surface and ascertain the surface roughness. The functional groups present at the surface of the nanoparticles were investigated using the Fourier transform infrared spectroscopy method. The optical properties of these particles were investigated using the UV-visible spectroscopy. Further, the produced nanoparticles were used to adsorb NO2- ions from aqueous solutions. The results showed that the nanoparticles which were heated at 90°C (hydroxide forms) presented a higher activity for nitrite ions removal than those that were heated at 400°C (oxide forms). This may be related to nitrite ions preferential adsorption to hydroxide forms rather than to oxide forms; in both cases (90°C and 400°C), zinc oxide nanoparticles presented higher nitrite removal activity.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":"61 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79485468","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}
This review considers and summarizes findings of the studies on metals’ coexisting forms in bottom sediments of surface water bodies. This makes it possible to assess metals’ migration ability in the “bottom sediments – water” system and their potential bioavailability for hydrobionts. The coexisting forms of metals in bottom sediments depend on their chemical properties and the component composition of the solid phase. Metals are distributed among exchangeable, carbonate, oxide, organic and residual fractions of bottom sediments. The highest migration ability is observed for metals contained in the first three fractions. Metals migration from organic and residual fractions hardly ever takes place. The oxygen regime, pH and redox potential, total dissolved solids and water temperature, concentration and component composition of organic substances affect the exchange of metals between bottom sediments and overlying water. The metal mobility in the “bottom sediments – water” system will increase under conditions of climate change. This is because cases of dissolved oxygen deficiency become more common, the total dissolved solids get higher in concentration, and pH and redox potential is reduced. Therefore, the development of methods to reduce metals migration from bottom sediments is a relevant task, which is discussed in the present paper.
{"title":"Bioavailability and migration features of metals in “bottom sediments – water” system under the action of different environmental factors","authors":"P. Linnik, R. Linnik, V. Zhezherya","doi":"10.19261/cjm.2023.1049","DOIUrl":"https://doi.org/10.19261/cjm.2023.1049","url":null,"abstract":"This review considers and summarizes findings of the studies on metals’ coexisting forms in bottom sediments of surface water bodies. This makes it possible to assess metals’ migration ability in the “bottom sediments – water” system and their potential bioavailability for hydrobionts. The coexisting forms of metals in bottom sediments depend on their chemical properties and the component composition of the solid phase. Metals are distributed among exchangeable, carbonate, oxide, organic and residual fractions of bottom sediments. The highest migration ability is observed for metals contained in the first three fractions. Metals migration from organic and residual fractions hardly ever takes place. The oxygen regime, pH and redox potential, total dissolved solids and water temperature, concentration and component composition of organic substances affect the exchange of metals between bottom sediments and overlying water. The metal mobility in the “bottom sediments – water” system will increase under conditions of climate change. This is because cases of dissolved oxygen deficiency become more common, the total dissolved solids get higher in concentration, and pH and redox potential is reduced. Therefore, the development of methods to reduce metals migration from bottom sediments is a relevant task, which is discussed in the present paper.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":"16 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72803414","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}
Hadjira Naoui, M. Benalia, Soumaya Hachani, A. Djeridane, Z. Ben Ahmed, V. Seidel, Yousfi Mohamed
Samples of oils from seven types of Ficus carica L. fruits from Algeria were investigated through determinations of their chemical characteristics, quantifying sterols and tocopherols, and analysis of the fatty acids profiles using gas chromatography, and evaluation of antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and total antioxidant activity (TAA) using phosphomolybdenum methods. The results show that acid values ranged from 3.14 to 6.95 mg KOH/g indicating on the high amount of free fatty acids in the figs oils. Neutral lipids occupy a very important proportion of the crude figs oils (NL: 60.30–98.40%) compared to glycolipids (GL: 0.58–28.00%) and phospholipids (PL: 0.40-11.70%). Linoleic (11.70–34.74%) and linolenic (1.15–35.27%) were the major unsaturated fatty acids found in lipid fractions, while the main fraction of saturated fatty acid was palmitic. The tocopherols and sterols contents in fig oils ranged from 14.27 to 108.55 mg α-TE/g lipids and from 0.36 to 2.80 mg CE/g lipids respectively. The best inhibition concentration (IC50) of DPPH antioxidant activity was marked by GL (0.23–1.06 g/L) and PL (0.67–1.23 g/L). The strongest TAA was also marked by GL (IC50: 2.84 to 10.08 g/L) and PL (IC50: 3.73–11.30 g/L). This finding demonstrated for the first time that the studied figs oils possessed good antioxidant activity which may be associated with their alleged health benefits.
{"title":"Chemical composition and antioxidant activity of lipids from Ficus carica L. fruits","authors":"Hadjira Naoui, M. Benalia, Soumaya Hachani, A. Djeridane, Z. Ben Ahmed, V. Seidel, Yousfi Mohamed","doi":"10.19261/cjm.2022.1029","DOIUrl":"https://doi.org/10.19261/cjm.2022.1029","url":null,"abstract":"Samples of oils from seven types of Ficus carica L. fruits from Algeria were investigated through determinations of their chemical characteristics, quantifying sterols and tocopherols, and analysis of the fatty acids profiles using gas chromatography, and evaluation of antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and total antioxidant activity (TAA) using phosphomolybdenum methods. The results show that acid values ranged from 3.14 to 6.95 mg KOH/g indicating on the high amount of free fatty acids in the figs oils. Neutral lipids occupy a very important proportion of the crude figs oils (NL: 60.30–98.40%) compared to glycolipids (GL: 0.58–28.00%) and phospholipids (PL: 0.40-11.70%). Linoleic (11.70–34.74%) and linolenic (1.15–35.27%) were the major unsaturated fatty acids found in lipid fractions, while the main fraction of saturated fatty acid was palmitic. The tocopherols and sterols contents in fig oils ranged from 14.27 to 108.55 mg α-TE/g lipids and from 0.36 to 2.80 mg CE/g lipids respectively. The best inhibition concentration (IC50) of DPPH antioxidant activity was marked by GL (0.23–1.06 g/L) and PL (0.67–1.23 g/L). The strongest TAA was also marked by GL (IC50: 2.84 to 10.08 g/L) and PL (IC50: 3.73–11.30 g/L). This finding demonstrated for the first time that the studied figs oils possessed good antioxidant activity which may be associated with their alleged health benefits.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":"35 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75269274","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}
This paper is dedicated to the synthesis of a copolymer with reducing properties obtained by functionalizing chitosan with quercetin and determining the antioxidant activity of the derivatives obtained depending on the molar mass of the polymer. For this purpose, low molecular weight chitosan was obtained by oxidizing commercial chitosan with hydrogen peroxide and further functionalization with quercetin by the covalent grafting method. The functionalization process was performed through the following steps: functionalization of chitosan with ethyl chloroformate to increase the reactivity of the amine group to the hydroxyl group of quercetin and grafting the quercetin molecule to the synthesized intermediate. The comparative antioxidant properties of the composite obtained by grafting technical chitosan with quercetin and by grafting low molecular weight chitosan were studied by the DPPH (2,2-diphenyl-1-picrylhydrazyl radical) method. The obtained results indicate that a decrease in the molecular weight of chitosan contributed to its grafting with quercetin. As a result, the functionalized polymer composite acquired a higher antioxidant activity and can be successfully used to inhibit the oxidation of various organic substrates in the cosmetic, food and pharmaceutical industries.
{"title":"Synthesis of quercetin functionalized chitosan and determination of antioxidant properties","authors":"M. Gonta, G. Duca, E. Sîrbu, S. Robu, L. Mocanu","doi":"10.19261/cjm.2023.910","DOIUrl":"https://doi.org/10.19261/cjm.2023.910","url":null,"abstract":"This paper is dedicated to the synthesis of a copolymer with reducing properties obtained by functionalizing chitosan with quercetin and determining the antioxidant activity of the derivatives obtained depending on the molar mass of the polymer. For this purpose, low molecular weight chitosan was obtained by oxidizing commercial chitosan with hydrogen peroxide and further functionalization with quercetin by the covalent grafting method. The functionalization process was performed through the following steps: functionalization of chitosan with ethyl chloroformate to increase the reactivity of the amine group to the hydroxyl group of quercetin and grafting the quercetin molecule to the synthesized intermediate. The comparative antioxidant properties of the composite obtained by grafting technical chitosan with quercetin and by grafting low molecular weight chitosan were studied by the DPPH (2,2-diphenyl-1-picrylhydrazyl radical) method. The obtained results indicate that a decrease in the molecular weight of chitosan contributed to its grafting with quercetin. As a result, the functionalized polymer composite acquired a higher antioxidant activity and can be successfully used to inhibit the oxidation of various organic substrates in the cosmetic, food and pharmaceutical industries.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":"28 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81224307","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}
Cheeses ripened in animal skin sacks belong to traditional cheeses that are strongly connected to the culture and history of the country from which they originate. Their main specificity is anaerobic ripening in an animal skin sack. The aim of this study was to determine the volatile compounds of Croatian cheeses in a sack of lamb skin produced from either raw cow’s or goat’s milk and relate them to the aroma of these traditional cheeses. Volatile compounds were extracted by headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) and analysed by gas chromatography-mass spectrometry (GC-MS). A total of 32 volatiles were identified in the cheese samples, including 12 carboxylic acids, 8 esters, 6 alcohols, 3 ketones, 2 hydrocarbons and 1 aldehyde. In the samples obtained by HS-SPME, the fatty acids and alcohols were the most abundant, while in the samples obtained by USE, the fatty acids were the most abundant.
{"title":"Volatile compounds identified in traditional croatian cow’s and goat’s cheeses matured in lambskin sack determined by GC-MS analysis","authors":"Ani Radonis, M. Žekić","doi":"10.19261/cjm.2023.1076","DOIUrl":"https://doi.org/10.19261/cjm.2023.1076","url":null,"abstract":"Cheeses ripened in animal skin sacks belong to traditional cheeses that are strongly connected to the culture and history of the country from which they originate. Their main specificity is anaerobic ripening in an animal skin sack. The aim of this study was to determine the volatile compounds of Croatian cheeses in a sack of lamb skin produced from either raw cow’s or goat’s milk and relate them to the aroma of these traditional cheeses. Volatile compounds were extracted by headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) and analysed by gas chromatography-mass spectrometry (GC-MS). A total of 32 volatiles were identified in the cheese samples, including 12 carboxylic acids, 8 esters, 6 alcohols, 3 ketones, 2 hydrocarbons and 1 aldehyde. In the samples obtained by HS-SPME, the fatty acids and alcohols were the most abundant, while in the samples obtained by USE, the fatty acids were the most abundant.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":"71 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83126563","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}
S. Blaja, L. Lungu, A. Ciocarlan, N. Vornicu, A. Aricu
Synthesis of novel tetranorlabdane compounds bearing 1,3,4-thiadiazole units and intermediary tetranorlabdane compounds with thiosemicarbazone fragment has been reported. The structures of the new synthesized compounds were confirmed using IR and 1H, 13C, and 15N NMR spectroscopy. The in vitro antifungal and antibacterial activities of the mentioned compounds have been evaluated. Results of this study have shown that the 1,3,4-thiadiazole-2-imine has excellent activity against tested strains of fungi and species of bacteria at minimum inhibitory concentration values of 0.125 and 2.5 μg/mL, respectively.
{"title":"Synthesis and evaluation of antimicrobial activity of tetranorlabdane compounds bearing 1,3,4-thiadiazole units","authors":"S. Blaja, L. Lungu, A. Ciocarlan, N. Vornicu, A. Aricu","doi":"10.19261/cjm.2022.1026","DOIUrl":"https://doi.org/10.19261/cjm.2022.1026","url":null,"abstract":"Synthesis of novel tetranorlabdane compounds bearing 1,3,4-thiadiazole units and intermediary tetranorlabdane compounds with thiosemicarbazone fragment has been reported. The structures of the new synthesized compounds were confirmed using IR and 1H, 13C, and 15N NMR spectroscopy. The in vitro antifungal and antibacterial activities of the mentioned compounds have been evaluated. Results of this study have shown that the 1,3,4-thiadiazole-2-imine has excellent activity against tested strains of fungi and species of bacteria at minimum inhibitory concentration values of 0.125 and 2.5 μg/mL, respectively.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":"83 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77693189","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：