On uniformly continuous Nemytskij operators generated by set-valued functions

Let I = [0, 1], let Y be a real normed linear space, C a convex cone in Y and Z a real Banach space. Denote by clb(Z) the set of all nonempty, convex, closed and bounded subsets of Z. If a superposition operator N generated by a set-valued function F : I × C → clb(Z) maps the set H _α (I, C) of all Hölder functions ${\varphi : I \to C}Let I = [0, 1], let Y be a real normed linear space, C a convex cone in Y and Z a real Banach space. Denote by clb(Z) the set of all nonempty, convex, closed and bounded subsets of Z. If a superposition operator N generated by a set-valued function F : I × C → clb(Z) maps the set H _α (I, C) of all H?lder functions j: I ? C{\varphi : I \to C} into the set H _β (I, clb(Z)) of all H?lder set-valued functions f: I ? clb(Z){\phi : I \to clb(Z)} and is uniformly continuous, then

F(x,y)=A(x,y) \text+* B(x),       x ? I, y ? CF(x,y)=A(x,y) \stackrel{*}{\text{+}} B(x),\qquad x \in I, y \in C      162. Screening Papaveraceae as Novel Antibiofilm Natural-Based Agents      Sylwia Zieli&#x;ska  Magdalena Dzi&#x;gwa-Becker  Adam Junka  Ewelina Pi&#x;tczak  Anna Jezierska-Domaradzka  Malwina Broyna  Justyna Paleczny  Aleksandra Sobiecka  Wojciech S&#x;upski  Eleonora Mess  Mariusz Kucharski  Serhat Sezai iek  Christian Zidorn  Adam Matkowski 《Molecules (Basel, Switzerland)》2021,26(16) The antimicrobial properties of herbs from Papaveraceae have been used in medicine for centuries. Nevertheless, mutual relationships between the individual bioactive substances contained in these plants remain poorly elucidated. In this work, phytochemical composition of extracts from the aerial and underground parts of five Papaveraceae species (Chelidonium majus L., Corydalis cava (L.) Schweigg. and Körte, C. cheilanthifolia Hemsl., C. pumila (Host) Rchb., and Fumaria vaillantii Loisel.) were examined using LC-ESI-MS/MS with a triple quadrupole analyzer. Large differences in the quality and quantity of all analyzed compounds were observed between species of different genera and also within one genus. Two groups of metabolites predominated in the phytochemical profiles. These were isoquinoline alkaloids and, in smaller amounts, non-phenolic carboxylic acids and phenolic compounds. In aerial and underground parts, 22 and 20 compounds were detected, respectively. These included: seven isoquinoline alkaloids: protopine, allocryptopine, coptisine, berberine, chelidonine, sanguinarine, and chelerythrine; five of their derivatives as well as non-alkaloids: malic acid, trans-aconitic acid, quinic acid, salicylic acid, trans-caffeic acid, p-coumaric acid, chlorogenic acid, quercetin, and kaempferol; and vanillin. The aerial parts were much richer in phenolic compounds regardless of the plant species. Characterized extracts were studied for their antimicrobial potential against planktonic and biofilm-producing cells of S. aureus, P. aeruginosa, and C. albicans. The impact of the extracts on cellular metabolic activity and biofilm biomass production was evaluated. Moreover, the antimicrobial activity of the extracts introduced to the polymeric carrier made of bacterial cellulose was assessed. Extracts of C. cheilanthifolia were found to be the most effective against all tested human pathogens. Multiple regression tests indicated a high antimicrobial impact of quercetin in extracts of aerial parts against planktonic cells of S. aureus, P. aeruginosa, and C. albicans, and no direct correlation between the composition of other bioactive substances and the results of antimicrobial activity were found. Conclusively, further investigations are required to identify the relations between recognized and unrecognized compounds within extracts and their biological properties.      163. Structural and electronic effects of oxazolidine ligands derived from (1R,2S)-ephedrine in the asymmetric addition of diethylzinc to aldehydes      Ewelina Błocka  Magdalena Jaworska  Anna Kozakiewicz  Mirosław Wełniak  Andrzej Wojtczak 《Tetrahedron: Asymmetry》2010,21(5):571-577 The purpose of this research was to determine the activity of chiral oxazolidine ligands prepared from (1R,2S)-ephedrine for the enantioselective addition of diethylzinc to aldehydes. The configuration on the newly formed C2 stereogenic center was determined as (2S) by X-ray structural analysis. Oxazolidine ligands reveal medium enantioselectivity with the ee exceeding 57%, and the yields obtained being 68–99%. The results indicate that the absolute configuration of the addition product depends not only on the N3-methyl as an important stereocontrol element but also on both the electronic and steric effects of the substrates and oxazolidine ligands.      164. Stereochemical effects in fragmentation of diastereoisomers of protected diethyl 1,2‐diamino‐alkylphosphonates      Ewelina Drabik  Roman Błaszczyk  Tadeusz Gajda  Marek Sochacki 《Rapid communications in mass spectrometry : RCM》2010,24(16):2324-2328 Diastereoisomers of diethyl 5‐substituted (2‐thioxo‐imidazolidin‐4‐yl)phosphonates, which can be regarded as protected diethyl 1,2‐diaminoalkylphosphonates, have been analyzed by electron ionization mass spectrometry. Significant differences in the fragmentation of cis‐ and trans‐diastereoisomers were found. The stereospecificity of the elimination of diethyl phosphonate and the loss of the diethoxyphosphoryl group were studied using specific labeled compounds and collision‐induced dissociation. The relative abundances of ions formed via these fragmentation processes can be used for differentiation of both diastereoisomers. Copyright © 2010 John Wiley & Sons, Ltd.      165. Feasible utility of inorganic remains from potable water purification process in chemical looping combustion studied in TG      Ewelina Ksepko 《Journal of Thermal Analysis and Calorimetry》2015,120(1):457-470       166. On the Coordination Behaviour of the hmta Toward Alkali Metal Cations in Presence of Perchlorate Anions      Rafal Kruszynski  Tomasz Sieranski  Marcin Swiatkowski  Marta Zielak  Jakub Wojciechowski  Magdalena Dzierzawska  Ewelina Czubacka 《Journal of chemical crystallography》2015,45(10-12):484-494       167. Drone Brood Homogenate as Natural Remedy for Treating Health Care Problem: A Scientific and Practical Approach      Ewelina Sidor  Ma&#x;gorzata Dugan 《Molecules (Basel, Switzerland)》2020,25(23) Drone brood homogenate is a little-known bee product used in folk medicine to treat various health problems. It is a very nutritious milky substance with high content of nutrients: proteins, lipids, fatty acids, carbohydrates, vitamins (A, B, E and D), and minerals. Moreover, when collected on early stage of larvae development, it is, most of all, rich source of sex hormone (testosterone, progesterone and estradiol). Some beekeepers consider drone brood as a waste product, although in some countries they use it to fight Varroa. Meanwhile, in many scientific reports a curative effect of bee drone homogenate in treating urgent global health problems have been confirmed, including ovarian dysfunction in women and male infertility, thyroid and immunity disorders, as well as malnutrition in children. A few dietary supplements based on drone brood are available online. Many patents relating to drone brood-based dietary supplements have been filed in Russia, but their prevalence in EU countries is still limited. Further research is needed to fully recognize the pharmacological activity and increase the use of drone brood.      168. Labeled vs. Label-Free Raman Imaging of Lipids in Endothelial Cells of Various Origins      Basseem Radwan  Adriana Adamczyk  Szymon Tott  Krzysztof Czamara  Katarzyna Kaminska  Ewelina Matuszyk  Malgorzata Baranska 《Molecules (Basel, Switzerland)》2020,25(23) Endothelial cells (EC) constitute a single layer of the lining of blood vessels and play an important role in maintaining cardiovascular homeostasis. Endothelial dysfunction has been recognized as a primary or secondary cause of many diseases and it manifests itself, among others, by increased lipid content or a change in the lipid composition in the EC. Therefore, the analysis of cellular lipids is crucial to understand the mechanisms of disease development. Tumor necrosis factor alpha (TNF-α)-induced inflammation of EC alters the lipid content of cells, which can be detected by Raman spectroscopy. By default, lipid detection is carried out in a label-free manner, and these compounds are recognized based on their spectral profile characteristics. We consider (3S,3′S)-astaxanthin (AXT), a natural dye with a characteristic resonance spectrum, as a new Raman probe for the detection of lipids in the EC of various vascular beds, i.e., the aorta, brain and heart. AXT colocalizes with lipids in cells, enabling imaging of lipid-rich cellular components in a time-dependent manner using laser power 10 times lower than that commonly used to measure biological samples. The results show that AXT can be used to study lipids distribution in EC at various locations, suggesting its use as a universal probe for studying cellular lipids using Raman spectroscopy. The use of labeled Raman imaging of lipids in the EC of various organs could contribute to their easier identification and to a better understanding of the development and progression of various vascular diseases, and it could also potentially improve their diagnosis and treatment.      169. Direct Nanospectroscopic Verification of the Amyloid Aggregation Pathway          下载免费PDF全文 Dr. Ewelina Lipiec  Dr. David Perez‐Guaita  Janina Kaderli  Prof. Bayden R. Wood  Prof. Renato Zenobi 《Angewandte Chemie (International ed. in English)》2018,57(28):8519-8524 The aggregation pathways of neurodegenerative peptides determine the disease etiology, and their better understanding can lead to strategies for early disease treatment. Previous research has allowed modelling of hypothetic aggregation pathways. However, their direct experimental observation has been elusive owing to methodological limitations. Herein, we demonstrate that nanoscale chemical mapping by tip‐enhanced Raman spectroscopy of single amyloid fibrils at various stages of aggregation captures the fibril formation process. We identify changes in TERS/Raman marker bands for Aβ1‐42, including the amide III band (above 1255 cm?1 for turns/random coil and below 1255 cm?1 for β‐sheet conformation). The spatial distribution of β‐sheets in aggregates is determined, allowing verification of a particular fibrillogenesis pathway, starting from aggregation of monomers to meta‐stable oligomers, which then rearrange to ordered β‐sheets, already at the oligomeric or protofibrillar stage.      170. New thiourea organocatalysts and their application for the synthesis of 5-(1H-indol-3-yl)methyl-2,2-dimethyl-1,3-dioxane-4,6-diones a source of chiral 3-indoylmethyl ketenes      Ewelina Najda-Mocarska  Anna Zakaszewska  Karolina Janikowska 《合成通讯》2018,48(1):14-25 The stereoselective properties of modified thiourea organocatalysts were tested in the Friedel–Crafts alkylation of indole with 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones, which produces chiral 5-((1H-indol-3-yl)(aryl)methyl)-2,2-dimethyl-1,3-dioxane-4,6-diones. Based on a tentative reaction mechanism for ((S)-N-benzyl-2-(3-(3,5-bis(trifluoromethyl)phenyl)thioureido)-N,3,3-trimethylbutanamide organocatalysts, modifications were applied in four selected regions. Systematic structure-stereoselectivity relationship study allowed designing the best efficient organocatalyst for the investigated Friedel–Crafts alkylation of indole with 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones.      [首页] « 上一页 [12] [13] [14] [15] [16] 17 [18] [19] [20] [21] 下一页 » 末  页»

Screening Papaveraceae as Novel Antibiofilm Natural-Based Agents

The antimicrobial properties of herbs from Papaveraceae have been used in medicine for centuries. Nevertheless, mutual relationships between the individual bioactive substances contained in these plants remain poorly elucidated. In this work, phytochemical composition of extracts from the aerial and underground parts of five Papaveraceae species (Chelidonium majus L., Corydalis cava (L.) Schweigg. and Körte, C. cheilanthifolia Hemsl., C. pumila (Host) Rchb., and Fumaria vaillantii Loisel.) were examined using LC-ESI-MS/MS with a triple quadrupole analyzer. Large differences in the quality and quantity of all analyzed compounds were observed between species of different genera and also within one genus. Two groups of metabolites predominated in the phytochemical profiles. These were isoquinoline alkaloids and, in smaller amounts, non-phenolic carboxylic acids and phenolic compounds. In aerial and underground parts, 22 and 20 compounds were detected, respectively. These included: seven isoquinoline alkaloids: protopine, allocryptopine, coptisine, berberine, chelidonine, sanguinarine, and chelerythrine; five of their derivatives as well as non-alkaloids: malic acid, trans-aconitic acid, quinic acid, salicylic acid, trans-caffeic acid, p-coumaric acid, chlorogenic acid, quercetin, and kaempferol; and vanillin. The aerial parts were much richer in phenolic compounds regardless of the plant species. Characterized extracts were studied for their antimicrobial potential against planktonic and biofilm-producing cells of S. aureus, P. aeruginosa, and C. albicans. The impact of the extracts on cellular metabolic activity and biofilm biomass production was evaluated. Moreover, the antimicrobial activity of the extracts introduced to the polymeric carrier made of bacterial cellulose was assessed. Extracts of C. cheilanthifolia were found to be the most effective against all tested human pathogens. Multiple regression tests indicated a high antimicrobial impact of quercetin in extracts of aerial parts against planktonic cells of S. aureus, P. aeruginosa, and C. albicans, and no direct correlation between the composition of other bioactive substances and the results of antimicrobial activity were found. Conclusively, further investigations are required to identify the relations between recognized and unrecognized compounds within extracts and their biological properties.     

Structural and electronic effects of oxazolidine ligands derived from (1R,2S)-ephedrine in the asymmetric addition of diethylzinc to aldehydes

The purpose of this research was to determine the activity of chiral oxazolidine ligands prepared from (1R,2S)-ephedrine for the enantioselective addition of diethylzinc to aldehydes. The configuration on the newly formed C2 stereogenic center was determined as (2S) by X-ray structural analysis. Oxazolidine ligands reveal medium enantioselectivity with the ee exceeding 57%, and the yields obtained being 68–99%. The results indicate that the absolute configuration of the addition product depends not only on the N3-methyl as an important stereocontrol element but also on both the electronic and steric effects of the substrates and oxazolidine ligands.     

Stereochemical effects in fragmentation of diastereoisomers of protected diethyl 1,2‐diamino‐alkylphosphonates

Diastereoisomers of diethyl 5‐substituted (2‐thioxo‐imidazolidin‐4‐yl)phosphonates, which can be regarded as protected diethyl 1,2‐diaminoalkylphosphonates, have been analyzed by electron ionization mass spectrometry. Significant differences in the fragmentation of cis‐ and trans‐diastereoisomers were found. The stereospecificity of the elimination of diethyl phosphonate and the loss of the diethoxyphosphoryl group were studied using specific labeled compounds and collision‐induced dissociation. The relative abundances of ions formed via these fragmentation processes can be used for differentiation of both diastereoisomers. Copyright © 2010 John Wiley & Sons, Ltd.     

Drone Brood Homogenate as Natural Remedy for Treating Health Care Problem: A Scientific and Practical Approach

Drone brood homogenate is a little-known bee product used in folk medicine to treat various health problems. It is a very nutritious milky substance with high content of nutrients: proteins, lipids, fatty acids, carbohydrates, vitamins (A, B, E and D), and minerals. Moreover, when collected on early stage of larvae development, it is, most of all, rich source of sex hormone (testosterone, progesterone and estradiol). Some beekeepers consider drone brood as a waste product, although in some countries they use it to fight Varroa. Meanwhile, in many scientific reports a curative effect of bee drone homogenate in treating urgent global health problems have been confirmed, including ovarian dysfunction in women and male infertility, thyroid and immunity disorders, as well as malnutrition in children. A few dietary supplements based on drone brood are available online. Many patents relating to drone brood-based dietary supplements have been filed in Russia, but their prevalence in EU countries is still limited. Further research is needed to fully recognize the pharmacological activity and increase the use of drone brood.     

Labeled vs. Label-Free Raman Imaging of Lipids in Endothelial Cells of Various Origins

Endothelial cells (EC) constitute a single layer of the lining of blood vessels and play an important role in maintaining cardiovascular homeostasis. Endothelial dysfunction has been recognized as a primary or secondary cause of many diseases and it manifests itself, among others, by increased lipid content or a change in the lipid composition in the EC. Therefore, the analysis of cellular lipids is crucial to understand the mechanisms of disease development. Tumor necrosis factor alpha (TNF-α)-induced inflammation of EC alters the lipid content of cells, which can be detected by Raman spectroscopy. By default, lipid detection is carried out in a label-free manner, and these compounds are recognized based on their spectral profile characteristics. We consider (3S,3′S)-astaxanthin (AXT), a natural dye with a characteristic resonance spectrum, as a new Raman probe for the detection of lipids in the EC of various vascular beds, i.e., the aorta, brain and heart. AXT colocalizes with lipids in cells, enabling imaging of lipid-rich cellular components in a time-dependent manner using laser power 10 times lower than that commonly used to measure biological samples. The results show that AXT can be used to study lipids distribution in EC at various locations, suggesting its use as a universal probe for studying cellular lipids using Raman spectroscopy. The use of labeled Raman imaging of lipids in the EC of various organs could contribute to their easier identification and to a better understanding of the development and progression of various vascular diseases, and it could also potentially improve their diagnosis and treatment.     

Direct Nanospectroscopic Verification of the Amyloid Aggregation Pathway

The aggregation pathways of neurodegenerative peptides determine the disease etiology, and their better understanding can lead to strategies for early disease treatment. Previous research has allowed modelling of hypothetic aggregation pathways. However, their direct experimental observation has been elusive owing to methodological limitations. Herein, we demonstrate that nanoscale chemical mapping by tip‐enhanced Raman spectroscopy of single amyloid fibrils at various stages of aggregation captures the fibril formation process. We identify changes in TERS/Raman marker bands for Aβ_1‐42, including the amide III band (above 1255 cm^?1 for turns/random coil and below 1255 cm^?1 for β‐sheet conformation). The spatial distribution of β‐sheets in aggregates is determined, allowing verification of a particular fibrillogenesis pathway, starting from aggregation of monomers to meta‐stable oligomers, which then rearrange to ordered β‐sheets, already at the oligomeric or protofibrillar stage.     

New thiourea organocatalysts and their application for the synthesis of 5-(1H-indol-3-yl)methyl-2,2-dimethyl-1,3-dioxane-4,6-diones a source of chiral 3-indoylmethyl ketenes

The stereoselective properties of modified thiourea organocatalysts were tested in the Friedel–Crafts alkylation of indole with 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones, which produces chiral 5-((1H-indol-3-yl)(aryl)methyl)-2,2-dimethyl-1,3-dioxane-4,6-diones. Based on a tentative reaction mechanism for ((S)-N-benzyl-2-(3-(3,5-bis(trifluoromethyl)phenyl)thioureido)-N,3,3-trimethylbutanamide organocatalysts, modifications were applied in four selected regions. Systematic structure-stereoselectivity relationship study allowed designing the best efficient organocatalyst for the investigated Friedel–Crafts alkylation of indole with 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones.