Wyniki wyszukiwania dla: QUINOLINE DERIVATIVES.
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Sensorless IPMSM drive with rotor position estimator based on analysis of phase current derivatives
PublikacjaThis paper describes a sensorless Interior Permanent Magnet Synchronous Motor (IPMSM) drive designed for traction applications. Wide-speed sensorless operation is provided with the use of three methods of rotor position estimation designed for: a standstill, low- and high-speed range. The paper focuses on the high-speed estimation algorithm. The estimator uses the derivatives of motor phase currentsresulting from PWM modulation...
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Chemometric analysis of UV-Vis spektra of associated forms of Amphotericin B and its derivatives
PublikacjaPrzedmiotem badań był proces agregacji nowych pochodnych antybiotyku polienowego Amfoterycyny B. Do śledzenia procesu agregacji wykorzystano spektroskopię absorpcyjną w zakresie widzialnym i bliskiego nadfioletu. Zastosowanie zaawansowanych technik chemometrycznych pozwoliło na dogłębną analizę agregacji tych pochodnych, co pozwoliło na wyciągniecie następujacych wniosków: i) w przypadku wszystkich pochodnych przy stężeniach poniżej...
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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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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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Indole-Acrylonitrile Derivatives as Potential Antitumor and Antimicrobial Agents—Synthesis, In Vitro and In Silico Studies
PublikacjaA series of 2-(1H-indol-2-yl)-3-acrylonitrile derivatives, 2a–x, 3, 4a–b, 5a–d, 6a–b, and 7, were synthesized as potential antitumor and antimicrobial agents. The structures of the prepared compounds were evaluated based on elemental analysis, IR, 1H- and 13NMR, as well as MS spectra. X-ray crystal analysis of the representative 2-(1H-indol-2-yl)-3-acrylonitrile 2l showed that the acrylonitrile double bond was Z-configured. All...
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Xanthone synthetic derivatives with high anticandidal activity and positive mycostatic selectivity index values
PublikacjaWith the current massive increases in drug-resistant microbial infection as well as the significant role of fungal infections in the death toll of COVID-19, discovering new antifungals is extremely important. Natural and synthetic xanthones are promising derivatives, although only few reports have demonstrated their antifungal mechanism of action in detail. Newly synthetized by us xanthone derivative 44 exhibited strong antifungal...
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Photoresponsive Amide-Based Derivatives of Azobenzene-4,4′-Dicarboxylic Acid—Experimental and Theoretical Studies
PublikacjaAzobenzene derivatives are one of the most important molecular switches for biological and material science applications. Although these systems represent a well-known group of compounds, there remains a need to identify the factors influencing their photochemical properties in order to design azobenzene-based technologies in a rational way. In this contribution, we describe the synthesis and characterization of two novel amides...
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Improving the regulation of the derivatives market as an objective prerequisite for sustainable development of the global financial system
PublikacjaThe development of financial markets is characterized by the emergence of new financial instruments, in particular derivatives, the risk level analysis of which is complicated. Counterparties are not always fully aware of and do not adequately assess the potential risks of derivatives, which may lead to large financial losses and sometimes bankruptcies. The purpose of the study is to generalize approaches to regulating derivative...
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Synthesis of conjugates of muramyl dipeptide and nor-muramyl dipeptide derivatives with adenosine as potential immunosuppressants
PublikacjaPrzedstawiono syntezę koniugatów pochodnych muramylodipeptydu (MDP) i nor-MDP z adenozyną jako potencjalnych związków o działaniu immunosupresyjnym. Jako substrat zastosowano rybozyd 6-chloropuryny, który łączonp poprzez 1,2-diaminoetan z pochodną MDP lub nor-MDP. Do syntezy wykorzystano pochodne MDP zawierające w części peptydowej D-aminokwasy (D-Ala, D-Val, D-Ser, D-Pro, D-2-ABA). Jako odczynniki sprzęgające zastosowano EDCI...
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Synthesis of phosphono and phosphate derivatives of hydroxyimino-D-alditols as new potential antifungal agents
PublikacjaIn search for new effective we antyfungals we focus on two enzymes involved in biosynthesis of the fungal cell wall. The first enzyme is glucosamine-6-phosphate (GlmS), which catalyzes transformation of D-fructose-6-phosphate (Fru-6P) to D-glucosamine-6-phodphate (GlcN-6P) in the chitin biosynthesis pathway. The second enzyme is phosphomannose isomerase (PMI) repored to play a crucial role in biosynthesis of many mannosylated structures,...
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Synthesis of conjugates of muramyl dipeptide and nor-muramyl dipeptide derivatives with adenosine as potential immunosuppressant
PublikacjaZaprezentowano syntezę koniugatów adenozyny z pochodnymi muramylo- i nor-muramylodipeptydów zawierających w części peptydowej D-aminokwasy (D-Ala, D-Val, D-Ser, D-Pro, D-2-ABA). Jako substrat zastosowano rybozyd 6-chloropuryny, który łączono poprzez 1,2-diaminoetan z odpowiednimi pochodnymi MDP lub nor-MDP w obecności EDCI i HOBt. Struktury otrzymanych związków zostały potwierdzone widmami 1H i 13C NMR (500 MHz), widmami MS oraz...
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The products of electro- and photochemical oxidation of 2-hydroxyacridinone, the reference compound of antitumor imidazoacridinone derivatives
PublikacjaBadano reakcje elektrochemicznego utleniania 2-hydroksyakrydonu, związku modelowego aktywnych przeciwnowotworowo pochodnych imidazoakrydonu. Do badań zastosowano metody woltamperometrii cyklicznej, metodę spektroelektrochemiczną oraz elektrolizę przy kontrolowanym potencjale. Badano też reakcje fotochemicznego utleniania. Badania prowadzono w ramach szerszego problemu poznania przemian aktywacji metabolicznej pochodnych hydroksyakrydonu...
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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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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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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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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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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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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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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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Carboxymethylated starch and cellulose derivatives-based film as human skin equivalent for adhesive properties testing
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Diosgenyl 2-amino-2-deoxy-β-D-galactopyranoside: synthesis, derivatives and antimicrobial activity
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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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Spectral Characteristic and Preliminary Anticancer Activity in vitro of Selected Rhodanine‐3‐carboxylic Acids Derivatives
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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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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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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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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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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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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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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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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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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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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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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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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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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.