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Search results for: FLAVONOID DERIVATIVES
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Conjugation of polyethylenimine and its derivatives to carbon-encapsulated iron nanoparticles
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Natural composites based on polysaccharide derivatives: preparation and physicochemical properties
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Studies on the influence of β-cyclodextrin derivatives on the physical stability of famotidine
PublicationThe usage of Fourier transform infrared spectroscopy, near infrared spectroscopy, differential scanning calorimetry and microscopy is presented in this work focused on the exploration of the effect of CD on the physical stability of famotidine (FAM). The most significant information was achieved by analysis of the second derivatives ofnear infrared (NIR) spectra recorded. Changes in the shape of spectra derivatives allow...
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Photophysics of 7-Hydroxytetrahydroisoquinoline-3-carboxylic Acid and Its Derivatives
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New Chalcones Derivatives With Potent Antitumor Activity And Their Metabolism In Vitro
PublicationChalcone derivatives exhibit a broad range of biological activities, with antioxidant and cytotoxic properties among the most studied. Despite numerous reports on chalcones as cytotoxic, and potentially anticancer agents, very little is know on their actual mechanism of activity. Generally, chalcones are considered as antimitotic agents, which interfere with tubulin assembly.We have recently developed a new class of chalcones with...
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The content of butyl- and phenyltin derivatives in the sediment from the Port of Gdansk
PublicationPróbki osadów portowych były pobierane dwukrotnie (2003 i 2005)z różnych nabrzeży w Porcie Gdańsk. Rdzenie o długości 25 cm były dzielone na warstwy o grubości 2 i 5cm i po odpowiednim przygotowaniu (w tym także analizie sitowej) były poddawane analizie na zawartość związkow cynoorganicznych.W analizowanych póbkach (o różnej granulacji cząstek osadu) wykryto i oznaczono względnie duże stężenie TBT, DBT, MBT oraz MPhT. Osady portowe...
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Synthesis of ester derivatives of propylene glycol in the presence of zinc carboxylates.
PublicationZbadano wpływ temperatury i stężenia karboksylanów cynku na przebieg estryfikacji glikolu propylenowego kwasami tłuszczowymi. Otrzymano emulgatory, w których maksymalne stężenie monoestru wynosiło 55-57%.
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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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NUMERICAL ESTIMATION OF HULL HYDRODYNAMIC DERIVATIVES IN SHIP MANOUVERING PREDICTION
PublicationOperating in crowded waterways pose a risk of accidents and disasters due to maneuvering limitations of the ship. In order to predict ship’s maneuvering characteristics at the design stage, model tests are often executed as the most accurate prediction tool. Two approaches can be distinguished here: free running model tests and numerical simulations based on planar motion model with the use of hydrodynamic derivatives obtained...
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Numerical Estimation of Hull Hydrodynamic Derivatives in Ship Maneuvering Prediction
PublicationPrediction of the maneuvering characteristics of the ship at the design stage can be done by means of model tests, computational simulations or a combination of both. The model tests can be realized as direct simulation of the standard maneuvers with the free running model, which gives the most accurate results, but is also the least affordable as it requires very large tank or natural lake, as well as complex equipment of the...
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Therapeutic Potential of Carnosine and Its Derivatives in the Treatment of Human Diseases
PublicationDespite significant progress in the pathogenesis, diagnosis, treatment, and prevention of cancer and neurodegenerative diseases, their occurrence and mortality are still high around theworld. The resistance of cancer cells to the drugs remains a significant problem in oncology today,while in the case of neuro-degenerative diseases, therapies reversing the process are still yet to be found. Furthermore, it is important to seek new...
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Fractional Problems with Right-Handed Riemann-Liouville Fractional Derivatives
PublicationIn this paper, we investigate the existence of solutions for advanced fractional differential equations containing the right-handed Riemann-Liouville fractional derivative both with nonlinear boundary conditions and also with initial conditions given at the end point T of interval [0,T ]. We use both the method of successive approximations, the Banach fixed point theorem and the monotone iterative technique, as well. Linear problems...
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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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Expedited antenna optimization with numerical derivatives and gradient change tracking
PublicationDesign automation has been playing an increasing role in the development of novel antenna structures for various applications. One of its aspects is electromagnetic (EM)-driven design closure, typically applied upon establishing the antenna topology, and aiming at adjustment of geometry parameters to boost the performance figures as much as possible. Parametric optimization is often realized using local methods given usually reasonable...
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Reduction of Derivative pipeline effort in water turbine
PublicationThe paper presents an approach to evaluate and reduce the effort of the derivative pipeline in a water turbine of a hydrostatic power station in its vulnerable spots. Potential places of the biggest effort of the structure, as well as the coefficient of displacement and safety factor related to them were identified using FEM numerical method. Pipeline reinforcement was designed and made based on FEM analysis. Original technology...
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Antifungal action of the oxathiolone-fused chalcone derivative
PublicationAMG-148, pochodna chalkonu z pierścieniem oksatiolonowym, wykazuje aktywność przeciwgrzybową in vitro wobec szczepów grzybowych patogennych dla człowieka, z wartościami minimalnych stężeń hamujących wzrost mieszczących się w zakresie 1-16 mikrogramów na mililitr, natomiast w wyższych stężeniach związek ten działa grzybobójczo. Obecność głównych białek oporności wielolekowej, Cdr1p, Cgr2p lub Mdr1p nie wpływa znacząco na aktywność...
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Effect of Extraction Methods on Polyphenols, Flavonoids, Mineral Elements, and Biological Activities of Essential Oil and Extracts of Mentha pulegium L.
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Electrochemical simulation of enzymatic transformations studied for the selected antitumor acridine derivatives
PublicationThe elucidation of the metabolic pathways and the biotransformation mechanisms of potential drugs is a crucial point in drug development. It allows to know the activation routes of the new biologically active compounds, especially in respect to their possible toxicity. Generally, in vivo or in vitro experiments with liver microsomes or hepatocytes are performed. However, these testing schemes are tedious, time consuming and of...
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Synthesis of conjugates of Combretastatin A-4 with tuftsin derivatives as potential anticancer agents
PublicationZaprezentowano syntezę nowych koniugatów Combretastatyny A-4 z pochodnymi tuftsyny i retro-tuftsyny, jako potencjalnych związków przeciwnowotworowych.
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Reaction of thio and seleno phosphoric acid derivatives with O-thioacylated hydroxylamine
PublicationZbadano reakcję siarkowych i selenowych analogów kwasu O,O-neopentylidenofosforowego z O-tiopiwaloilo-N-tert-butylohydroksyloaminą, w której to następuje rozszczepienie wiązania N-O. Znaleziono korelację pomiędzy potencjałem utleniającym anionu pochodnej kwasu fosforowego a przebiegiem badanej reakcji.
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Artificial Neural Networks for Prediction of Antibacterial Activity in Series of Imidazole Derivatives
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In vitro and in vivo biological activities of azulene derivatives with potential applications in medicine
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Synthesis of conjugates of amino-combretastatin with tuftsin derivatives as potential anticancer agents
PublicationOpisano syntezę nowych koniugatów 3'-N-(tuftsyno lub retro-tuftsyno)-amino-kombretastatyny jako potencjalnych związków przeciw-nowotworowych. Do syntezy amino-kombretastatyny (amino-CA-4) wykorzystano reakację Wittiga a koniugatów metodę DPPA. Mamy nadzieję, że połączenie pochodnych tuftsyny z amino-CA-4 wpłynie na polepszenie właściwości terapeutycznych CA-4.
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N-Alkyl Derivatives of L-Glutamine As Inhibitors of Glutamine - Utilizing Enzymes
PublicationA general facile method to synthesize the N-gamma-alkyl and N-gamma,N-gamma-dialkyl derivatives of L-glutamine (1a-d) from L-glutamic acid as a starting substrate is presented. The obtained compounds are shown to inhibit three diferent glutamine-utilizing enzymes, namely: glutaminase, gamma-glutamyl transpeptidase, and glucosamine-6-phosphate synthase, with inhibitory constants within the milimolar range.
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IPMSM rotor position estimator based on analysis of phase current derivatives
PublicationThis paper describes an algorithm for estimation of IPMSM angular rotor position. The algorithm uses derivatives of motor phase currents resulting from PWM modulation to obtain the rotor position. The presented method is designed for medium- and high-speed range, since it is based on determination of the EMF vector. Algorithm is characterised by a very simple formulae. The calculation of rotor position is performed in every PWM...
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Fentanyl and its derivatives as a group of new psychoactive substances (designer drugs)
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Azomacrocyclic derivatives of imidazole: synthesis, structure, and metal ion complexation properties
PublicationOtrzymano nowe azokorony zawierające resztę imidazolu w makropierścieniu. Na drodze sprzęgania z solami diazoniowymiotrzymano pochodne imidazolu 2-metylo, 4-metylo oraz 4-fenyloimidazolu. Synteza była prowadzona w warunkach wysokiego ciśnienia. Dla 21-członowej pochodnej 4-metyloimidazolu określono strukturę jej adduktu z wodą przy pomocy metod rentgenograficznych.Zdolność kompleksowania jonów metali badano spektrofotometrycznie...
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Interactions of amphotericin B derivatives with lipid membranes - a molecular dynamics study
PublicationW pracy analizowano oddziaływanie dwóch nisko-toksycznych pochodnych amfoterycyny B (związki SAmE i PAmE) z modelami błon lipidowych. Badania wykonane zostały za pomocą dynamiki molekularnej. Modele błon oprócz fosfolipidów DMPC zawierały odpowiednio cholesterol (model błony zwierzęcej) lub ertosterol (model błony grzybowej). Analiza wyników wykazała, że obie pochodne amfoterycyny B zachowują się inaczej w błonie cholesterolowej...
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Chemosensitization of multidrug resistant Candida albicans by the oxathiolone fused chalcone derivatives
PublicationThree structurally related oxathiolone fused chalcone derivatives appeared effective chemosensitizers, able to restore in part sensitivity to fluconazole of multidrug-resistant C.albicans strains. Compound 21 effectively chemosensitized cells resistant due to the overexpression of the MDR1 gene, compound 6 reduced resistance of cells overexpressing the ABC-type drug transporters CDR1/CDR2 and derivative 18 partially reversed fluconazole...
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Spectroscopic insight into supramolecular assemblies of boric acid derivatives and β-cyclodextrin
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Effect of renal replacement therapy on selected arachidonic acid derivatives concentration
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Solvent extraction of copper ions by 3-substituted derivatives of β-diketones
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Synthesis and Study of Antifungal Properties of New Cationic Beta-Glucan Derivatives
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Amine–alkyl derivatives of hydantoin: New tool to combat resistant bacteria
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Azomacrocyclic derivatives of imidazole: synthesis, structure, and metal ion complexation properties
PublicationNew azocrown ethers comprising imidazoles in the macrocycle have been synthesized. Imidazole, 2-methyl-, 4-methyl-, and 4-phenylimidazole were incorporated to form macrocyclic units by coupling with the appropriate bis-diazonium salts. The syntheseswere performed under high dilution conditions. The X-ray structure of a water adduct of the 21-membered crown ether derivative of 4-methylimidazole 8 has been solved. Metal...
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Antimicrobial activity of 5-arylidene aromatic derivatives of hydantoin. Part 2
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Kinetics of Flavoenzyme-Catalyzed Reduction of Tirapazamine Derivatives: Implications for Their Prooxidant Cytotoxicity
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Determination of the Stereostructure of Pyrimidine Nucleoside Derivatives with a Combination of Various Chiroptical Methods
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Anti-Helicobacter pylori activity of some newly synthesized derivatives of xanthone
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Investigations on the immunosuppressive activity of derivatives of mycophenolic acid in immature dendritic cell
PublicationThe main activity of mycophenolic acid (MPA) and its analogs is the inhibition of proliferation of T cells. Here, we hypothesized that MPA and its conjugates inhibits also the activity of antigen-presenting cells (APC) including dendritic cells (DCs). We tested the effect of novel amino acid derivatives of MPA and conjugates of MPA with acridines/acridones on DCs by flow cytometry, ELISA and MLR assay. Both acridines/acridone derivatives...
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Fully scalable one-pot method for the production of phosphonic graphene derivatives
PublicationGraphene oxide was functionalized with simultaneous reduction to produce phosphonated reduced graphene oxide in a novel, fully scalable, one-pot method. The phosphonic derivative of graphene was obtained through the reaction of graphene oxide with phosphorus trichloride in water. The newly synthesized reduced graphene oxide derivative was fully characterized by using spectroscopic methods along with thermal analysis. The morphology...
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The FMO analysis of the molecular interaction of fentanyl derivatives with the μ-opioid receptor
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Recent Trends in the Application of Chromatographic Techniques in the Analysis of Luteolin and Its Derivatives
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Synthesisand cytotoxic activity of conjugates of muramyl and normuramyl dipeptides with batracylin derivatives
PublicationOpisano syntezę analogów MDP oraz nor-MDP modyfikowanych w części peptydowej batracyliną i pochodnymi batracyliny. Opracowano udoskonaloną metodę syntezy batracyliny. Zaproponowana metoda pozwala na otrzymanie BAT w skali multi-gramowej. Zsyntetyzowane analogi nie wykazały aktywności cytotoksycznej w badaniach prowadzonych w NCI (Bethesda, USA). W testach in vitro przeprowadzonych w Akademii Medycznej w Gdańsku dwa analogi redukowały...
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Synthesis and antitumor activity of conjugates of muramyldipeptide or normuramyldipeptide with hydroxyacridine/acridone derivatives
PublicationOpisano syntezę analogów MDP oraz nor-MDP modyfikowanych w części peptydowej pochodnymi hydroksyakrydyny/akrydonu i dwóch analogów modyfikowanych pochodnymi 1-nitro-9-hydroksyetylo(propylo)aminoakrydyny. Tylko związki zawierające pochodne 1-nitro-9-hydroksyetylo(propylo)aminoakrydyny wykazały wysoką aktywność cytotoksyczną badaną na 60 liniach ludzkich komórek nowotworowych, na nowotwór prostaty i AIDS-related lymphoma (ARL). Związek...
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New class of quaternary ammonium salts, derivatives of methyl D-glucopyranosides.
PublicationReakcja zasad azotowych z 6-O-p-tozylo-alfa-D-glukopiranozydem metylu lub 6-O-tozylo-beta-D-glukopiranozydem metylu (prowadzona w skali mikro) dając odpowiednie sole amoniowe. Jako zasady azotowe użyto pirydyny, 2-metylopirydyny i trimetyloaminy. Produkty zostały przebadane przy użyciu spektroskopii 1H, 13C NMR, spektroskopii mas oraz analizy elementarnej a budowa jednego z nich została dodatkowo potwierdzona za pomocą rentgenowskiej...
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Studies of the effects of antifungal cationic derivatives of amphotericin B on human erythrocytes.
PublicationBadano nową grupę kationowych pochodnych amfoterycyny B pod kątem zależności pomiędzy ich zdolnością do asocjacji i selektywną toksycznością. We wszystkich przypadkach stosowano amfoterycynę B jako związek odniesienia. Jako miarę efektu toksycznego in vitro badanych związków stosowano wypływ wewnątrzkomórkowego potasu oraz hemolizę. Miarą aktywności przeciwgrzybowej był MIC i utrata potasu wewnatrzkomórkowego. Do oceny stopnia...
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N-alkyl derivatives of 2-amino-2-deoxy-D-glucose
PublicationMono- i di-N-alkilowe pochodne 1,3,4,6-tetra-O-acetylo-2-amino-2-deoksy-beta-D-glukozy (alkil = metyl, etyl, propyl, butyl, pentyl, heksyl, benzyl) otrzymano w wyniku redukcyjnej alkilacji per-O-acetylo-D-glukozaminy. (N-etylo, N-propylo, N-butylo, N-pentylo, N-heksylo)-1,3,4,6-tetra-O-acetylo-2-amino-2-deoksy-beta-D-glukozy deacetylowano w celu podjęcia prób enzymatycznej fosforylacji. Wszystkie produkty scharakteryzowano za pomocą...
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Macrocyclic derivatives of imidazole as chromoionophores for bismuth(III)/lead(II) pair
Publication18-membered diazomacrocycles with imidazole or 4-methylimidazole residue as a part of macrocycle were used as chromoionophores in bismuth(III) and lead(II) dual selective optodes for the first time. Cellulose triacetate membranes doped with macrocyclic chromoionophores are bismuth(III) and lead(II) selective with color change from orange/red to different shades of blue and violet, respectively. Results obtained for model and real...
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Novel amides of mycophenolic acid and some heterocyclic derivatives as immunosuppressive agents
PublicationThe group of new amide derivatives of mycophenolic acid (MPA) and selected heterocyclic amines was synthesised as potential immunosuppressive agents functioning as inosine-5'-monophosphate dehydrogenase (IMPDH) uncompetitive inhibitors. The synthesis employed uronium-type activating system (TBTU/HOBt/DIPEA) while or phosphonic acid anhydride method (T3P/Py) facilitating amides to be obtained in moderate to excellent yields without...