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Search results for: HYDROXAMIC ACIDS
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Lawesson's reagent (LR) for direct thionation of hydroxamic acids. Substituent effect on LR reactivity
PublicationOkreślono zakres stosowalności i ogranicznia metody bezpośredniej tionacji kwasów hydroksamowych (HAA) za pomocą odczynnika Lawessona (LR). Przedmiotem badań było 35 HAA o wzorze ogólnym R1CON(R2)OH gdzie: R1 = alkil, aryl, benzyl, etoksykarbonylometylen, cynamyl, heteroaryl, a R2 = alkil, aryl. Ustalono, że wydajności kwasów tiohydroksamowych są niskie, gdy wyjściowy HAA posiada w swojej strukturze duże objętościowo reszty R1...
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On the reaction of bis(phosphothioyl)disulfanes with hydroxamic acids, part I: Ionic versus radical reaction pathways
PublicationReaktywność disulfanów bisfosforotiowych jest mało poznana. Wiadomo, że wykazują one aktywność pestycydową związaną z inhibicją acetylocholinesterazy. Z kolei, kwasy hydroksamowe stosuje się jako efektywne środki do detoksykacji trucizn fosforoorganicznych. Zbadano reakcje soli kwasów benzohydroksamowych z elektrofilowymi disulfanami bisfosfonotiowymi. Badania prowadzono z użyciem disulfanów bisfosforo-, bisfosfono- i bisfosfinotiowych....
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Lower rim substituted p-tert-butyl-calix[4]arene. Part 17. Synthesis, extractive and ionophoric properties of p-tert-butylcalix[4]arene appended with hydroxamic acid moieties
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Lower rim substituted p-tert-butyl-calix[4]arene. Part 17. synthesis, extractive and ionophoric properties of p-tert-butylcalix[4]arene appended with hydroxamix acid moieties
PublicationThe synthesis and characterization of four p-tert-butylcalix[4]arene-hydroxamic acidc are reported. The dependence of the metal ion binding, assessed by liquid extraction of the metal nitrates from water into dichloromethane in individual and competitive experiments, on the ligand structure, is presented. The results showed that those ligands could be successfully used in separation process of trnasition and heavy metals often...
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Novel Cell Permeable Polymers of N-Substituted L-2,3-Diaminopropionic Acid (DAPEGs) and Cellular Consequences of Their Interactions with Nucleic Acids
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Is the Fatty Acids Profile in Blood a Good Predictor of Liver Changes? Correlation of Fatty Acids Profile with Fatty Acids Content in the Liver
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Complexation of amino acids derivatives in water by calix[4]arene phosphonic acids
PublicationSeries of the calix[4]arene phosphonic acids with various substituents at the lower rim was synthesized. Complexing properties of these receptors towards methyl esters of six amino acids strongly depended on the calix[4]arene conformation flexibility. The complex formation processes were monitored using 1H NMR spectroscopy (deuterated phosphate buffer at pD 7.3, 22 oC) and association constant values were evaluated. Inherently...
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Chirality Measures of α-Amino Acids
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Chlorogenic acids – their properties, occurrence and analysis
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Study on the concentration of acids by membrane distillation
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Modification of Bacterial Cellulose with Quaternary Ammonium Compounds Based on Fatty Acids and Amino Acids and the Effect on Antimicrobial Activity
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Applications of Unnatural Amino Acids in Protease Probes
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Inhibitors of amino acids biosynthesis as antifungal agents
PublicationFungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic amino acids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential amino acid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular amino acids exhibit...
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Boron Difluoride Complexes of Carbamoyl Meldrum's Acids
Publication5-[Hydroxy(aryl/alkylamino)methylene]-2,2-dimethyl-1,3-dioxane-4,6-diones react with BF3•Et2O in mild conditions leading to the formation of boron difluoride complexes of carbamoyl Meldrum's acids. The X-ray structure has been obtained for one representative complex. The obtained new compounds are fairly stable at standard ambient conditions and easily isolable.
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Propensity of salicylamide and ethenzamide cocrystallization with aromatic carboxylic acids
PublicationThe cocrystallization of salicylamide (2-hydroxybenzamide, SMD) and ethenzamide (2-ethoxybenzamide, EMD) with aromatic carboxylic acids was examined both experimentally and theoretically. The supramolecular synthesis taking advantage of the droplet evaporative crystallization (DEC) technique was combined with powder diffraction and vibrational spectroscopy as the analytical tools. This led to identification of eleven new cocrystals...
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Bile Acids: Key Players in Inflammatory Bowel Diseases?
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Electric chips for rapid detection and quantification of nucleic acids
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Ion Chromatography in Environmental Analysis of Selected Organic Acids
PublicationLow molecular mass carboxylic acids (LCAs) occur in many environmental compartments dueto natural processes and human activity. When volatile and nonvolatile acids are to be monitored then liquidchromatography, including ion chromatography seems a method of choice. At high pH the acids are inionized form and can be separated as carboxylats by means of anion exchange chromatography. LCAs canalso be separated at low pH by ion exclusion...
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Mechanism of the reaction of Lawesson's reagent with N-alkylhydroxamic acids
PublicationIdentyfikacja fosforowych produktów powstających w reakcji kwasów hydroksamowych z odczynnikiem Lawessona pozwoliła ustalić mechanizm tytułowej reakcji. Wykorzystano w tym celu spektroskopię 31P NMR. Wzorce labilnych produktów otrzymano na niezależnej drodze syntetycznej lub przeprowadzono je w trwałe pochodne, które wyizolowano z mieszanin reakcyjnych. Produktem przejściowym badanej reakcji okazał się odpowiedni O-ditiofosfonylowany...
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S-thioacyldithiophosphates in the synthesis of thiohydroxamic acids and O-thioacylhydroxylamines
PublicationDitiofosforany tioacylu to trwałe, łatwo osiągalne z kwasów karboksylowych środki tioacylujące. Z powodu ich niskiej reaktywności wobec nukleofili tlenowych i wysokiej wobec nukleofili azotowych znalazły zastosowanie w syntezie kwasów tiohydroksamowych bezpośrednio z hydroksyloamin z niechronioną grupą hydroksylową. W przypadku dużej zawady przestrzennej można otrzymać O-tioacylohydroksyloaminy.
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Biodegradability of modified emulsifiers - esters of polyols and fatty acids
PublicationBadano podatność na biodegradację wybranych emulgatorów estrów polioli i kwasów tłuszczowych przy użyciu testu zamkniętej butelki (OECD 301 D). Stwierdzono, że badane emulgatory nie mogą zostać uznane za łatwo ulegające biodegradacji. Najwyższy poziom rozkładu (57,3%) osiągnął emulgator C14Gna, najniższy (29,8%) AEGNa.
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Fatty acids as molecular carriers in cleavable antifungal conjugates
PublicationConjugates composed of C2-18 fatty acid (FA) residues as a molecular carrier and 5-fluorocytosine (5-FC) as an active agent, released upon the action of intracellular esterases on the ester bond between FA and “trimethyl lock” intramolecular linker, demonstrate good in vitro activity against human pathogenic yeasts of Candida spp. The minimal inhibitory concentrations (MIC) values for the most active conjugates containing caprylic...
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Synthesis and biological activity of mycophenolic acid-amino acid derivatives
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Synthesis and biological activity of mycophenolic acid-amino acid derivatives
PublicationIn search of new immunosuppressants, mycophenolic acid (MPA) was coupled with amino acid methyl esters followed by hydrolysis to analogs bearing free carboxylic groups. The obtained compunds were tested in vitro as growth inhibitors of lymphoid cell line (Jurkat) and human peripheral blood mononuclear cells (PBMC) from healthy donors. According to obtained results recovering of free carboxylic group increased their activity. Additionally,...
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Hyaluronic acid/tannic acid films for wound healing application
PublicationIn this study, thin films based on hyaluronic acid (HA) with tannic acid (TA) were investigated in three different weight ratios (80HA/20TA, 50HA/50TA, 20HA/80TA) for their application as materials for wound healing. Surface free energy, as well as their roughness, mechanical properties, water vapor permeability rate, and antioxidant activity were determined. Moreover, their compatibility with blood and osteoblast cells was investigated....
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Anticancer Properties of Amino Acid and Peptide Derivatives of Mycophenolic Acid
PublicationBackground: Although Mycophenolic Acid (MPA) is applied as prodrugs in clinic as an immunosuppressant, it also possesses anticancer activity. MPA acts as Inosine-5’-Monophosphate Dehydrogenase (IMPDH) inhibitor, where the carboxylic group at the end of the side chain interacts with Ser 276 of the enzyme via hydrogen bonds. Therefore, MPA derivatives with other polar groups indicated high inhibition too. On the other hand, potent...
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Immunosuppressive properties of amino acid and peptide derivatives of mycophenolic acid
PublicationMycophenolic acid (MPA) was coupled with amino acids and biologically active peptides including derivatives of tuftsin to modify its immunosuppressive properties. Both amino acid unit in the case of simple MPA amides and modifications within peptide moiety of MPA - tuftsin conjugates influenced the observed activity. Antiproliferative potential of the obtained conjugates was investigated in vitro and MPA amides with threonine methyl...
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Occurrence and Determination of Volatile Fatty Acids in Wastewater of Different Origin
PublicationOpracowano metodykę oznaczania krótkołańcuchowych alifatycznych kwasów monokarboksylowych w ściekach rożnego pochodzenia stosując ekstrakcję za pomocą eteru metylo-tert-butylowego na etapie przygotowania próbek i chromatografię gazową z kolumną kapilarną Stabilwax-DA i Rtx-624, natomiast na etapie detekcji stosowano spektrometr mas.
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α-Amino Acids In Water: A Review Of VCD And ROA Spectra
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Peroxidative metabolism of fatty acids in the course of tick-borne encephalitis
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Applicability of phenolic acids as effective enhancers of cocrystals solubility of methylxanthines
PublicationApplicability of phenolic acids as potential cocrystal formers for methylxanthine derivatives was analyzed both in terms of cocrystallization probabilities and solubility advantage. The cocrystal formation abilities were evaluated using mixing enthalpy estimated within the conductor like screening model for real solvents (COSMO-RS) framework. The solubility improvement of potential cocrystals was estimated by formulation of the...
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Recent advances in extraction and analysis procedures of natural chlorogenic acids
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Calibration of POCIS and PASSIL passive samplers – influence of humic acids
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Capillary Electrophoresis in Determination of Low Molecular Mass Organic Acids
PublicationThis paper presents overviews the capabilities of capillary electrophoretic techniques to determine low molecular mass organic acids in a variety of aqueous, gas and solid samples. It mainly focuses on short - chain carboxylic acids containing one or more carboxylic groups and possibly some other functional groups (hydroxyl, keto-, amino- etc.). Finally the procedures applied to the determine the acids in different matrices are...
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Occurrence and Determination of Volatile Fatty Acids in Landfill Leachate and Gas
PublicationIn landfills containing biological matter volatile fatty acids (VFAs) are generated at high rate at the early stage of waste disposal and their content in leachate is high as compared to the leachate from old parts of landfill since they are converted to methane gas. Monitoring of the leachate for the content of VFAs can help determine the processes occurring in waste and possible effect of the leachate on the environment in the...
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Occurrence and Determination of Volatile Fatty Acids in Landfill Leachate and Gas
PublicationIn landfills containing biological matter volatile fatty acids (VFAs) are generated at high rate at the early stage of waste disposal and their content in leachate is high as compared to the leachate from old parts of landfill since they are converted to methane gas. Monitoring of the leachate for the content of VFAs can help determine the processes occurring in waste and possible effect of the leachate on the environment in the...
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Green Analytical Chemistry in Determination of Volatile Fatty Acids in Wastewater
PublicationCharakterystyka metodyk oznaczania lotnych kwasów tłuszczowych w próbkach wodnych, opierających się na Zasadach Zielonej Chemii. Opis zastosowania techniki bezpośredniego dozowania próbki wodnej do chromatografu gazowego, techniki analizy fazy nadpowierzchniowej oraz techniki mikroestrakcji do fazy stacjonarnej.
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Hydrogen and chalcogen bonds in crystals of chalcogenadiazolecarboxylic acids – competition or cooperation?
PublicationThis article presents crystal structures of chalcogenadiazolecarboxylic acids bearing both a hydrogen and a chalcogen bond donor. The selected molecules varied in the size of the aromatic unit, the chalcogen atom and/or the position of the carboxyl group in the core structure. The most common synthons in their lattice are "R" _"2" ^"2" (8) self-complementary acid dimers or four-membered [Ch···N]2 rings. Supramolecular synthons...
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Composition of fatty acids in selected sorts of biscuits, offered for children
PublicationThe fatty acid (FA) composition, especially total trans-fatty acids (TFA) content in 12 assortments of biscuits offered for children, produced by four different companies, were determined by gas chromatography. Total fat content of the biscuit samples ranged from 2.2 to 22.8 g/100 g of product. The major FAs were palmitic C16:0, oleic C18:1, and linoleic C18:2 acids. Depending on the biscuit type, the total saturated fatty acids...
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The Role of Electron Transfer in the Fragmentation of Phenyl and Cyclohexyl Boronic Acids
PublicationIn this study, novel measurements of negative ion formation in neutral potassium-neutral boronic acid collisions are reported in electron transfer experiments. The fragmentation pattern of phenylboronic acid is comprehensively investigated for a wide range of collision energies, i.e., from 10 to 1000 eV in the laboratory frame, allowing some of the most relevant dissociation channels to be probed. These studies were performed in...
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Determination and identification of organic acids in wine samples. Problems and challenges.
PublicationFor long time, organic acids were underestimated. However, during last two decades there is an increasing interest of natural compounds having antioxidant, antimicrobial and anti-inflammatory properties thus organic acids are very preferable. Wine stands as one of the sources of organic acids since they are responsible for its organoleptic and aestethic character. Nevertheless, it is important to not exceed acceptable level of...
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Hydration of amino acids: FTIR spectra and molecular dynamics studies
PublicationThe hydration of selected amino acids, alanine, glycine, proline, valine, isoleucine and phenylalanine, has been studied in aqueous solutions by means of FTIR spectra of HDO isotopically diluted in H2O. The difference spectra procedure and the chemometric method have been applied to remove the contribution of bulk water and thus to separate the spectra of solute-affected HDO. To support interpretation of obtained spectral results,...
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Synthesis and antimicrobial activity of amino acid and peptide derivatives of mycophenolic acid
PublicationThe series of 16 novel amino acid and peptide mycophenolic acid (MPA) derivatives was obtained as potential antibacterial agents. Coupling of MPA with respective amines was optimized with condensing reagents such as EDCI/DMAP and T3P/TEA. Amino acid analogs were received both as methyl esters and also with the free carboxylic group. The biological activity of the products was tested on five references bacterial strains: Klebsiella...
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How to eliminate the formation of chlorogenic acids artefacts during plants analysis? Sea sand disruption method (SSDM) in the HPLC analysis of chlorogenic acids and their native derivatives in plants
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Formation, occurrence and determination of volatile fatty acids in environmental and related samples
PublicationKrótkołańcuchowe alifatyczne kwasy monokarboksylowe mogą być oznaczane w różnych próbkach środowiskowych,za pomocą techniki mikroekstrakcji do fazy stacjonarnej z fazy nadpowierzchniowej na etapie przygotowanie próbek oraz chromatografii gazowej sprzężonej ze spektrometrią mas na etapie oznaczeń końcowych.Opracowana metodykę z powodzeniem zastosowano do oznaczenia tych kwasów w próbkach ścieków pochodzących z farmy bydła.
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A Comprehensive Review of Chemistry, Sources and Bioavailability of Omega-3 Fatty Acids
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Characterization of fatty acids composition in the European beaver (Castor fiber L.).
PublicationW pracy przedstawiono zawartość lipidów , klas lipidów i skład kwasów tłuszczowych lipidów ogólnych uzyskanych z różnych tkanek bobra europejskiego (tkanka okołojelitowa, tkanka okołonerkowa, miesień uda, mięsień kreskowy, podskórna tkanka tłuszczowa, ogon). Wykazano różnice w zawartości lipidów i składzie KT w tkankach samic (n=7) i samców (n=3). Wykazano wysokie zawartości nienasyconych KT w tkankach bobrów w porównaniu z tkankami...
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Benzalkonium Salts of Amino Acids – Physicochemical Properties and Anti-Microbial Activity
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Oligomers and peptidomimetics consisting of methyl 3-amino-2,3-dideoxyhexopyranosiduronic acids
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The Application of Phenolic Acids in The Obtainment of Packaging Materials Based on Polymers—A Review
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