Search
Filters
total: 928
filtered: 876
Search results for: PHOSPHONIC DERIVATIVES
-
Photophysical and theoretical studies of diphenylacetylene derivatives with restricted rotation
Publication -
Synthesis of Thermally Stable Energetic 1,2,3-Triazole Derivatives
Publication -
Amphotericin B and Its New Derivatives - Mode of Action
PublicationAmphotericin B (AmB) is a well known antifungal and antiprotozoal antibiotic used in the clinic for several decades. Clinicalapplications of AmB, however, are limited by its nephrotoxicity and many other acute side effects which are not acceptable by patientswhen their life is not threaten. In order to improve the therapeutic index of this drug, lipid formulations have been introduced and manyefforts have been made to obtain less...
-
The biological activity of new tuftsin derivatives - induction of phagocytosis
PublicationFagocytoza odgrywa ważną rolę w ochronie organizmu przed różnymi mikroorganizmami. Proces ten może być indukowany przez różne czynniki np. endogenny immunomodulator jakim jest tuftsyna czy muramylo-dipeptyd (MDP), najmniejszy syntetyczny glikopeptyd bakteryjnej ściany komórkowej. Zsyntetyzowano nowe analogi MDP i nor-MDP z tuftsyną i retro-tuftsyną, które są zdolne do indukowania fagocytozy. Najbardziej obiecujące okazały się dwa...
-
Functionalization of cysteine derivatives by unsymmetrical disulfide bond formation
PublicationOpracowano metodę funkcjonalizacji pochodnych cysteiny przy pomocy tworzenia niesymetrycznego wiązania disulfidowego. Opracowana metoda okazała się bardzo łagodna, wydajna, i niewrażliwa na obecność dodatkowych grup funkcyjnych.
-
Electron ionization induced fragmentation of fluorinated derivatives of bisphenols
Publication -
Hydrophilic Films Based on Carboxymethylated Derivatives of Starch and Cellulose
Publication -
Emulsion-Based Gel Loaded with Ibuprofen and Its Derivatives
Publication -
Rhodotorulic Acid and its Derivatives: Synthesis, Properties, and Applications
PublicationSiderophores are low molecular weight compounds produced by microorganisms to scavenge iron in iron-deficient environments. Rhodotorulic acid, a natural hydroxamate siderophore, plays a vital role in iron acquisition for fungi and bacteria. As the simplest natural hydroxamate siderophore, it exhibits a high affinity for ferric ions, enabling it to form stable complexes that facilitate iron uptake and transport within microorganisms....
-
Antimycobacterial activity of 5-arylidene aromatic derivatives of hydantoin
Publication -
Solid phase synthesis of two muramyl pentapeptide derivatives
Publication -
Efficient synthesis of orthogonally protected spermidine and norspermidine derivatives
PublicationOtrzymano kilka chronionych pochodnych spermidyny i norspermidyny w wyniku reakcji cyjanoetylowania chronionych diamin, ochrony drugorzędowej grupy aminowej oraz redukcji otrzymanego nitrylu za pomocą wodorku litowo-glinowego w temperaturze 0° C.
-
Biological activity of conjugates of muramyl dipeptides with batracylin derivatives
PublicationW artykule opisano aktywność biologiczną koniugatów muramylo-dipeptydów z batracyliną lub pochodnymi batracyliny. Badania przeprowadzone w Akademii Medycznej w Gdańsku miały na celu oznaczenie immunomodulacyjnych właściwości tych koniugatów wobec subpopulacji leukocytów krwi obwodowej hodowanych w obecności komórek nowotworowych (K562, WEHI164, Ab melanoma). Leukocyty izolowane były z krwi obwodowej uzyskanej od zdrowych ochotników....
-
Thermodynamics aspects of interactions between acridine derivatives and DNA
PublicationDNA is a molecular target for many anticancer and antiviral drugs. Therefore, a clear understanding of the interaction of small molecules with DNA is important in the rational design of ligands that can bind to DNA with high affinity and selectivity. There are several methods to investigate interactions between drug and DNA. Some of them measure changing into DNA structures, such as lengthening and untwisting of helix of DNA. Other...
-
Microwave-assisted synthesis of zinc derivatives of potato starch
PublicationZincatated potato starch was prepared in a solid-state, microwave-assisted reaction using generated in situ sodium tetrahydroxozincate [Na2Zn(OH)4]. For comparison, zincatation of starch was also carriedout on convectional heating. Depending on the irradiation conditions, the products of either mono- or crosslinking esterification were formed. Higher power applied at shorter exposition offered products ofmonoesterification, and...
-
Acyl Meldrum's acid derivatives: application in organic synthesis
PublicationThis review is focused on one of the most important classes of Meldrum's acid derivatives commonly known as acyl Meldrum's acids. The preparation methods of these compounds are considered including the recently proposed and rather rarely used ones. The chemical properties of acyl Meldrum's acids are described in detail, including thermal stability and reactions with various nucleiophiles. The possible mechanisms of these transformations...
-
Hydration of urea and its derivatives - Volumetric and compressibility studies
PublicationThe densities and sound velocities at T = (288.15, 293.15, 298.15, 303.15 and 308.15) K have been measured for aqueous solutions of urea, N,N-dimethylurea, N,N-diethylurea, N-propylurea, N-butylurea. From these data the apparent molar volumes, V the apparent molar isentropic compressions, KS,, and the Passynski solvation numbers of solutes have been determined. The concentration dependencies of the calculated quantities, their...
-
Hedging Strategies of Derivatives Instruments for Commodity Trading Entities
PublicationHedging as an outcome of risk management arises to account several questions. Mentioned aspect of size of the hedging is one of them. Latter questioning refers to whether producer of manufacturer are willing to secure entire exposure, when the hedging should start, now or later in the future, what is the vision on market like direction of market, time of interest, magnitude of exposure, what would be the preferred instruments of...
-
Biological activity of conjugates of muramyl dipeptides with batracylin derivatives
PublicationZaprezentowano immunomodulacyjne właściwości nowych koniugatów batracyliny (BAT) z pochodnymi muramylodipeptydów wobec subpopulacji leukocytów krwi obwodowej hodowanych w obecności komórek linii nowotworowych. Leukocyty izolowane były z krwi obwodowej uzyskanej od zdrowych ochotników. Zbadane koniugaty MDP lub nor-MDP z batracyliną wykazały silniejsze własności hamujące proliferację komórek wybranych linii nowotworowych (K562,...
-
Synthesis of bicoumarin thiophosphate derivatives as steroid sulfatase inhibitors
PublicationBased on the frameworks of 7-hydroxy-2,3-dihydro-1H-cyclopenta[c]chromen-4-one, 3-hydroxy- 7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one and 3-hydroxy-8,9,10,11-tetrahydro-7H-cyclohepta[c] chromen-6-one, a series of bicoumarin thiophosphate analogs have been synthesized and biologically evaluated. Additionally, their binding modes have been modeled using docking techniques. The inhibitory properties of the synthesized compounds...
-
Do Phenyl Substituents Affect the Properties of Azobenzocrown Derivatives?
PublicationNew products of photo- and thermal rearrangements of 19-membered azoxybenzocrown with phenyl substituents in benzene rings in the para positions to oligooxyethylene fragments are characterized. The yields of photochemical transformations depend on the solvent. Para-hydroxyazocrown is formed with yields over 50% in propan-2-ol. Ortho-hydroxyazobenzocrown is obtained with yields up to 70% in toluene/acetic acid mixture. Macrocyclic...
-
Rhodotorulic Acid and its Derivatives: Synthesis, Properties, and Applications
PublicationSiderophores are low molecular weight compounds produced by microorganisms to scavenge iron in iron-deficient environments. Rhodotorulic acid (RA), a natural hydroxamate siderophore, plays a vital role in iron acquisition for fungi and bacteria. As the simplest natural hydroxamate siderophore, RA exhibits a high affinity for ferric ions, enabling it to form stable complexes that facilitate iron uptake and transport within microorganisms....
-
Densimetric and ultrasonic characterization of urea and its derivatives in water
PublicationW oparciu o pomiary gęstości dla serii roztworów jak i rozpuszczalnika wykonanych w temperaturach 15, 20, 25, 30 i 35oC wyznaczono pozorne molowe objętości mocznika, N-metylomocznika, N,N'-dimetylomocznika, N,N,N',N'-tetrametylomocznika, N-etylomocznika, N,N'-dietylomocznika jak i N-butylomocznika w wodzie. Dodatkowe pomiary szybkości dźwięku przeprowadzone w temperaturze 25oC pozwoliły obliczyć ściśliwości adiabatyczne, pozorne...
-
Copper(I) iodide ribbons coordinated with thiourea derivatives
PublicationTwo products of the reactions of CuI with 1-benzoyl-3-(4-bromophenyl)thiourea and with 1-benzoyl-3-(2-iodophenyl)thiourea have been obtained and characterized, namely poly[[[1-benzoyl-3-(4-bromophenyl)thiourea-κS]-µ3-iodidocopper(I)] acetone hemisolvate], {[CuI(C₁₄H₁₁BrN₂OS)]‧0.5C₃H₆O}ₙ, and poly-[µ₄-iodido-µ₃-iodido-[N-(benzo[d]thiazol-2-yl)benzamide-κN]dicopper(I)], [Cu₂I₂(C₁₄H₁₀N₂OS)]ₙ. Their structures, determined by single-crystal...
-
On Applications of Elements Modelled by Fractional Derivatives in Circuit Theory
PublicationIn this paper, concepts of fractional-order (FO) derivatives are reviewed and discussed with regard to element models applied in the circuit theory. The properties of FO derivatives required for the circuit-level modeling are formulated. Potential problems related to the generalization of transmission-line equations with the use of FO derivatives are presented. It is demonstrated that some formulations of FO derivatives have limited...
-
Biochemical, Structural Analysis, and Docking Studies of Spiropyrazoline Derivatives
PublicationIn this study, we evaluated the antiproliferative potential, DNA damage, crystal struc‐ tures, and docking calculation of two spiropyrazoline derivatives. The main focus of the research was to evaluate the antiproliferative potential of synthesized compounds towards eight cancer cell lines. Compound I demonstrated promising antiproliferative properties, especially toward the HL60 cell line, for which IC50 was equal to 9.4 μM/L....
-
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...
-
Synthesis and biological activity of mycophenolic acid-amino acid derivatives
Publication -
Supramolecular Interactions between β-Cyclodextrin and the Nucleobase Derivatives of Ferrocene
Publication -
Conjugation of polyethylenimine and its derivatives to carbon-encapsulated iron nanoparticles
Publication -
Natural composites based on polysaccharide derivatives: preparation and physicochemical properties
Publication -
Prediction of antimicrobial activity of imidazole derivatives by artificial neural networks
Publication -
Alkylation of 9-substituted guanine derivatives with α,ω-dihaloalkanes
Publication -
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...
-
Photophysics of 7-Hydroxytetrahydroisoquinoline-3-carboxylic Acid and Its Derivatives
Publication -
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%.
-
Antimicrobial and surface activity of 1-alkyl-3-methylimidazolium derivatives
PublicationWiedza na temat zależności struktura-aktywność umożliwia projektowanie i syntezę nowych kationowych związków amfifilowych ze zoptymalizowaną aktywnością antymikrobową na rzecz przyszłego rozwoju nowych środków dezynfekujących, sanityzujących czy konserwujących. Potrzeba projektowania i identyfikowania nowych związków posiadających właściwości przeciwbakteryjne jest rezultatem pojawienia się bardziej odpornych mikroorganizmów w...
-
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...
-
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...
-
Indirect Measurement of Motor Current Derivatives in PMSM Sensorless Drives
PublicationMotor current derivatives contain useful information for control algorithms, especially in sensorless electric drives. The measurement of motor current derivatives in electric motors supplied by voltage source inverter can be performed using di/dt transducers. However, in such a solution additional sensors have to be installed, e.g. Rogowski coils. Another approach is to measure current derivatives indirectly – by oversampling...
-
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,...
-
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...
-
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...
-
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...
-
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...
-
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...
-
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...
-
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...
-
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...
-
Artificial Neural Networks for Prediction of Antibacterial Activity in Series of Imidazole Derivatives
Publication