Wyniki wyszukiwania dla: CARNOSINE DERIVATIVES
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Synthesis and antimicrobial activity of 6-sulfo-6-deoxy-D-glucosamine and its derivatives
Publikacja6-Sulfo-6-deoxy-D-glucosamine (GlcN6S), 6-sulfo-6-deoxy-D-glucosaminitol (ADGS) and their N-acetyl and methyl ester derivatives have been synthesized and tested as inhibitors of enzymes catalyzing reactions of the UDP-GlcNAc pathway in bacteria and yeasts. GlcN6S and ADGS at micromolar concentrations inhibited glucosamine-6-phosphate (GlcN6P) synthase of microbial origin. The former was also inhibitory towards fungal GlcN6P N-acetyl...
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Synthesis of functionalized new conjugates of batracylin with tuftsin/ retro-tuftsin derivatives and their biological evaluation
PublikacjaNew batracylin conjugates with tuftsin/retro-tuftsin derivatives were designed and synthesized using T3P as a coupling agent. The conjugates possess an amide bond formed between the carboxyl group of heterocyclic molecule and the N-termini of the tuftsin/retro-tuftsin chain. The in vitro cytotoxic activity of the new analogues and their precursors was evaluated using a series of human and murine tumor cells. BAT conjugates containing...
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Monosubstituted hydrazone β-cyclodextrin derivatives for pH-sensitive complex formation with aromatic drugs
PublikacjaA new and convenient synthetic pathway was developed to produce monosubstituted cyclodextrins with high yields. Each of the β-cyclodextrin derivatives described in this work has an aromatic substituent connected with cyclodextrin core by a pH-sensitive hydrazone linker and a carbon chain. Carbon chains differ in lengths having one or three carbon atoms. The correlation between water solubility and linker length was determined using...
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Effect of chemical structure on complexation efficiency of aromatic drugs with cyclodextrins: The example of dibenzazepine derivatives
PublikacjaIt is widely believed that the hydrophobic effect governs the binding of guest molecules to cyclodextrins (CDs). However, it is also known that high hydrophobicity of guest molecules does not always translate to the formation of stable inclusion complexes with CDs. Indeed, a plethora of other factors can play a role in the efficiency of guest–CD interactions, rendering structure-based prediction of the complexation efficiency with...
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Novel N-(aryl/heteroaryl)-2-chlorobenzenesulfonamide derivatives: synthesis and anticancer activity evaluation
PublikacjaA new series of N-(aryl/heteroaryl)-2-chlorobenzenesulfonamide derivatives 4-21 have been synthesized, and evaluated at the National Cancer Institute (USA) for their in vitro activities against a panel of 60 different human cancer cell lines. Among them, compounds 16, 20 and 21 exhibited remarkable cytotoxic activity against numerous human cancer cell lines. We found that sulfonamide derivative 21 appeared to be more selective...
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Pochodne kwasu neopentylidenofosforoditiowego jako substraty do syntezy ugrupowania trisulfidowego
PublikacjaBadania przeprowadzone w Katedrze Chemii Organicznej Wydziału Chemicznego Politechniki Gdańskiej na przestrzeni ostatnich kilku lat, pokazały wszechstronność pochodnych kwasu neopentylidenofosforoditiowego [32] w syntezie symetrycznie i niesymetrycznie podstawionego ugrupowania disulfidowego. Wyniki powyższych badań doprowadziły do opracowania nowej strategii syntetycznej, umożliwiającej otrzymywanie...
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Addendum to ''On the derivative of the Legendre function of the first kind with respect to its degree''
PublikacjaPraca stanowi uzupełnienie wcześniejszej publikacji autora [J. Phys. A: Math. Gen. 39(2006) 15147-15172]. Przedstawiono w niej nowe wyrażenia dla pochodnej funkcji Legendre'a względem jej indeksu i zastosowano je do konstrukcji dwóch nowych reprezentacji funkcji Legendre'a drugiego rodzaju z całkowitym indeksem.
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Existence and uniqueness for neutral equations with delay dependant on a solution and its derivative
PublikacjaDla wykazania istnienia i jednoznaczności w pracy została zaprezentowana metoda porównawcza.
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A NUMERICAL STUDY ON THE DYNAMICS OF DENGUE DISEASE MODEL WITH FRACTIONAL PIECEWISE DERIVATIVE
PublikacjaThe aim of this paper is to study the dynamics of Dengue disease model using a novel piecewise derivative approach in the sense of singular and non-singular kernels. The singular kernel operator is in the sense of Caputo, whereas the non-singular kernel operator is the Atangana–Baleanu Caputo operator. The existence and uniqueness of a solution with piecewise derivative are examined for the aforementioned problem. The suggested...
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Signal Propagation in Electromagnetic Media Modelled by the Two-Sided Fractional Derivative
PublikacjaIn this paper, wave propagation is considered in a medium described by a fractional-order model, which is formulated with the use of the two-sided fractional derivative of Ortigueira and Machado. Although the relation of the derivative to causality is clearly specified in its definition, there is no obvious relation between causality of the derivative and causality of the transfer function induced by this derivative. Hence, causality...
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Proportional-derivative and Model-based Controllers for Control of a Variable Mass Manipulator
PublikacjaW artykule prezentowano wyniki analiza numeryczna dynamiki manipulatora o zmiennej masie. W skład manipulatora wchodzą jedynie członu i przeguby obrotowe. Ładowność chwytaka jest traktowana jako jedyny element o zmiennej masie. Podobnie jak w przypadku innych manipulatorów wyposażonych w przeguby obrotowe, parametry jego dynamika zależą od aktualnego ustawienia. Gdy przemieszczenia obejmują większy zakres roboczy, w równaniach...
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Proportional-Derivative and Model-Based Controllers for Control of a Variable Mass Manipulator
PublikacjaIn the paper, numerical analysis of dynamics of a variable mass manipulator is presented. A revolute joints composed manipulator is considered. Payload of the gripper is considered as the only element characterized by unknown value of its mass (variable between subsequent operations). As in other cases of the revolute joints composed manipulators, its behaviour dependents significantly on the pose of the manipulator. When the manipulator...
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Inactivation of glucosamine-6-phosphate synthase by N3-oxoacyl derivatives of L-2,3-diaminopropanoic acid
PublikacjaN3-oksoacylowe pochodne kwasu l-2,3-diaminopropanowego zawierające ugrupowanie epoksydowe lub układ sprzężonych wiązań podwójnych inaktywują syntaze glukozamino-6-fosforanu (GlcN-6-P) z S. cerevisiae. Wyniki badań kinetycznych inaktywacji enzymu wskazują na dwuetapowy przebieg tej reakcji, przy czym tworzenie kompleksu enzym:ligand poprzedza nieodwracalną modyfikację enzymu. Badane związki różniły się powinowactwem do centrum aktywnego...
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Chromogenic complexes and selective preconcentration of Fe(III) and Cu(II) by hydroxynaphthoyl-1,4,7,10-tetraazacyclododecane derivatives
PublikacjaSpektroskopowe oznaczanie zawartości jonów żelaza w różnych próbkach środowiskowych jest przedmiotem wieloletnich badań. Pomimo tego ciągle poszukuje się selektywnych odczynników zdolnych do tworzenia kompleksów z jonami żelaza(II) lub żelaza(III). 1,4,7,10-tetraazacyklododekan nie tworzy kompleksów z jonami żelaza, ale wprowadzając stosowne podstawniki można uzyskać właściwe ligandy. W reakcji acylowania otrzymano 1-(1-hydroksy-2-naftoilo)-1,4,7,10-tetraazacyklododekan...
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The organophosphorus sulfenyl bromides as versatile reagents for cysteine derivatives functionalization by unsymmetrical disulfide bond formation
PublikacjaWe have developed a convenient method for the synthesis of L-cysteine unsymmetrical disulfides under mild conditions with good to excellent yields. Described method is based on the straightforward preparation of the organophosphorus sulfenyl bromide readily available from bis-(5,5-dimethyl-2-thiono-1,3,2-dioxaphosphorinanyl) disulfide. The unsymmetrical disulfides can be obtained for L-cysteine derivatives and thiols bearing neutral...
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Fragmental Method KowWIN as the Powerful Tool for Prediction of Chromatographic Behavior of Novel Bioactive Urea Derivatives
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Chromogenic derivatives of new bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) - synthesis and properties
PublikacjaDerivatives of bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) with oxygen and sulphur atoms in the structure of aliphatic chains were successfully synthesised. The correlation between the ligand structure and its complexation properties was investigated by absorption spectroscopy. The formation of complexes of presented compounds with metal cations (Cu2+, Ni2+, Zn2+, Co2+, Fe2+ and Pb2+) was studied. Ligands 5-8 were additionally...
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Synthesis and biological activity of novel mycophenolic acid conjugates containing nitro-acridine/acridone derivatives
PublikacjaOpracowano warunki reakcji kwasu mykofenolowego z aminowymi pochodnymi akrydyn i akrydonów. Tak otrzymane koniugaty zostały scharakteryzowane, a następnie przebadane in vitro pod względem aktywności przeciwbiałaczkowej oraz immunosupresyjnej.
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Spectral Characteristic and Preliminary Anticancer Activity in vitro of Selected Rhodanine‐3‐carboxylic Acids Derivatives
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Investigation of the Binding Properties of the Cosmetic Peptide Argireline and Its Derivatives Towards Copper(II) Ions
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Antitumor Activity of Novel Benzensulfonamide Derivatives in View of their Physiochemical Properties Searched by Principal Component Analysis
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Synthesis and SAR-study for novel arylpiperazine derivatives of 5-arylidenehydantoin with α1-adrenoceptor antagonistic properties
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Tricyclic xanthine derivatives containing a basic substituent: adenosine receptor affinity and drug-related properties
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New chiral discotics with helical organization of the mesophase—liquid crystalline derivatives of dibenzotetraaza[14]annulene
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Molecular dynamics study on the influence of C-terminal sugar substitution on dynamics and conformation of vancomycin derivatives
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New D−π–D−π–A Systems Based on Phenothiazine Derivatives with Imidazole Structures for Photovoltaics
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Estimation of interior-permanent-magnet-synchronous-motor rotor position by analysis of phase-current derivatives
PublikacjaThis paper describes an algorithm for estimation of IPMSM rotor angular 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. Calculation of the motor position is performed in every PWM cycle. The standard SV-PWM method is used to determine...
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Carboxymethylated starch and cellulose derivatives-based film as human skin equivalent for adhesive properties testing
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The oxydiacetate and iminodiacetate complexes of oxidovanadium(IV) as the new series of the catalysts for the oligomerization of beta-olefin derivatives
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The new esters derivatives of betulin and betulinic acid in epidermoid squamous carcinoma treatment – In vitro studies
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Genetic and lifestyle variables associated with homocysteine concentrations and the distribution of folate derivatives in healthy premenopausal women
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Experimental and theoretical studies of spectroscopic properties of simple symmetrically substituted diphenylbuta-1,3-diyne derivatives
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Determining the true content of quercetin and its derivatives in plants employing SSDM and LC–MS analysis
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Diosgenyl 2-amino-2-deoxy-β-D-galactopyranoside: synthesis, derivatives and antimicrobial activity
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Derivatives of 1-nitroacridine induce apoptosis only in a limited number of human colon adenocarcinoma cells
PublikacjaPraca dotyczy indukcji apoptozy w komórkach ludzkich raków okrężnicy HT29 i HCT8 pod wpływem pochodnych 1-nitroakrydyny: C-857 i C-1748. Wykazano, że związki te w stężeniach biologicznie istotnych (EC90) indukują apoptozę tylko w części populacji komórek. Efekt ten uzależniony był od czasu inkubacji komórek ze związkiem, a nie zależał od stężenia związku.
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Elucidating the impact of enzymatic modifications on the structure, properties, and applications of cellulose, chitosan, starch and their derivatives: a review
PublikacjaPolysaccharides, as one of the most prominent natural biopolymers, display numerous biological activities and industrial applications. Nevertheless, some polysaccharides lack biological properties or display weak biological activities. Besides, practical usages of polysaccharides still remain challenging because of their poor solubility and inappropriate hydrophilic/hydrophobic balance. Hence, enzymatic or chemical modifications...
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Synthesis and biological activity of ester derivatives of mycophenolic acid and acridines/acridones as potential immunosuppressive agents
PublikacjaImproved derivatives of mycophenolic acid (MPA) are necessary to reduce the frequency of adverse effects, this drug exerts in treated patients. In this study, MPA was coupled with N-(x-hydroxyalkyl)-9-acridone-4-carboxamides or N-(x-hydroxyalkyl)acridine-4-carboxamides to give respective ester conjugates upon Yamaguchi protocol. This esterification required protection of phenol group in MPA. Designed conjugates revealed higher...
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Molecular modeling and evaluation of novel dibenzopyrrole derivatives as telomerase inhibitors and potential drug for cancer therapy
PublikacjaDuring previous years, many studies on synthesis, as well as on anti-tumor, anti-inflammatory and anti-bacterial activities of the pyrazole derivatives have been described. Certain pyrazole derivatives exhibit important pharmacological activities and have proved to be useful template in drug research. Considering importance of pyrazole template, in current work the series of novel inhibitors were designed by replacing central...
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Comments on various extensions of the Riemann–Liouville fractional derivatives : About the Leibniz and chain rule properties
PublikacjaStarting from the Riemann–Liouville derivative, many authors have built their own notion of fractional derivative in order to avoid some classical difficulties like a non zero derivative for a constant function or a rather complicated analogue of the Leibniz relation. Discussing in full generality the existence of such operator over continuous functions, we derive some obstruction Lemma which can be used to prove the triviality...
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Opioid Growth Factor and its Derivatives as Potential Non-toxic Multifunctional Anticancer and Analgesic Compounds
PublikacjaIn this paper, we review the structure-activity relationship of OGF and its analogues. We highlight also OGF derivatives with analgesic, immunomodulatory activity and the ability to penetrate the blood-brain barrier and may be used as safe agents enhancing chemotherapy efficacy and improving quality of life in cancer patients. The reviewed papers indicate that Met-enkephalin and its analogues are interesting candidates for the...
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General, Mild, and Metal-Free Functionalization of Indole and Its Derivatives Through Direct C3-Selenylation
PublikacjaA very mild method for the introduction of functionalized alkylselenyl group at C-3 position of the indole ring was developed. The proposed procedure consists of an electrophilic substitution of indole and its derivatives with bis(O,O-diisopropoxyphosphorothioyl) diselenide and subsequent cleavage of the P–Se bond with tetrabutylammonium fluoride in the presence of various electrophilic reagents. This method can be successfully...
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NADES propolis extracts - update 2023 and synthesis of derivatives of propolis ingredients
Dane BadawczeThis dataset contains results of our investigation aiming in determination of antimicrobial potential of the propolis extracts produced with deep eutectic solvents
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Enantioselective sensing of (S)-Thalidomide in blood plasma with a chiral naphthalene diimide derivative
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Fractional Variable-Order Derivative and Difference Operators and Their Applications to Dynamical Systems Modelling
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Apoptosis of human leukemia cells induced by imidazoacridinone derivative C-1311 (Symadex)
PublikacjaPraca dotyczy różnej wrażliwości komórek białaczek ludzkich do ulegania apoptozie pod wpływem pochodnej imidazoakrydonu C-1311, co jest zgodne z aktywnością cytotoksyczną tego związku (EC90) wobec badanych komórek.
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The Effect of Conjugation with Octaarginine, a Cell-Penetrating Peptide on Antifungal Activity of Imidazoacridinone Derivative
PublikacjaAcridine cell-penetrating peptide conjugates are an extremely important family of compounds in antitumor chemotherapy. These conjugates are not so widely analysed in antimicrobial therapy, although bioactive peptides could be used as nanocarriers to smuggle antimicrobial compounds. An octaarginine conjugate of an imidazoacridinone derivative (Compound 1-R8) synthetized by us exhibited high antifungal activity against reference...
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Multiple Solutions to Third-Order Differential Equations with Derivative Dependence and Deviating Arguments
PublikacjaIn this paper, we give some new results for multiplicity of positive (nonnegative) solutions for third-order differential equations with derivative dependence, deviating arguments and Stieltjes integral boundary conditions. We discuss our problem with advanced argument α and arbitrary β ∈ C([0,1],[0,1]), see problem (2). It means that argument β can change the character on [0,1], so β can be delayed in some set J ⊂ [0,1] and advanced...
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Carbon Nanotubes Derivatized with Mediators for Laccase Catalyzed Oxygen Reduction.
PublikacjaPrzedstawiono konstrukcję elektrody w której wykorzystano nanorurki modyfikowane znanym mediatorem (ABTS). Cząsteczki mediatora przyłączono do ścian bocznych nanorurek oraz do ich końców. Porównano parametry elektrod zbudowanych w oparciu o nanorurki modyfikowane kowalencyjnie w różny sposób. Zaobserwowano pozytywny wpływ modyfikowanych nanorurek na parametry elektrody.
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Inner derivations of special subrings of matrix rings and outerplanar digraphs.
PublikacjaTematem artykułu jest specjalny podpierścień pierścienia macierzy wyznaczony przez relację oraz digraf reprezentujący tę relację. Rozważane są takie relacje, dla których reprezentujące je digrafy są zewnętrznie planarne. W tym przypadku zostały udowodnione warunki konieczne i wystarczające na to, aby różniczkowanie pierścienia było wewnętrzne.
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Solid phase synthesis of 4,5,8-trihydroxy-9,10-anthraquinone-1-yl-(tuftsin or retro-tuftsin) derivatives
PublikacjaPrzedstawiono syntezę na fazie stałej połączeń leuko-1,4,5,8-tetra-hydroksyantrachinonów z pochodnymi tuftsyny i retro-tuftsyny zawierającymi wiązanie izopeptydowe. Do syntezy wykorzystano standardową metodę Fmoc i DIC jako odczynnik aktywujący.