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https://www.readbyqxmd.com/read/28344495/enantioselective-analysis-of-fluoxetine-in-pharmaceutical-formulations-by-capillary-zone-electrophoresis
#1
Melania Cârcu-Dobrin, Monica Budău, Gabriel Hancu, Laszlo Gagyi, Aura Rusu, Hajnal Kelemen
Fluoxetine is an antidepressant, a selective serotonin reuptake inhibitor (SSRI) used primarily in the treatment of major depression, panic disorder and obsessive compulsive disorder. Chiral separation of racemic fluoxetine is necessary due to its enantioselective metabolism. In order to develop a suitable method for chiral separation of fluoxetine, cyclodextrin (CD) modified capillary electrophoresis (CE) was employed. A large number of native and derivatized, neutral and ionized CD derivatives were screened to find the optimal chiral selector...
March 2017: Saudi Pharmaceutical Journal: SPJ: the Official Publication of the Saudi Pharmaceutical Society
https://www.readbyqxmd.com/read/28342851/site-specific-photocoupling-of-pbpa-mutated-scfv-antibodies-for-use-in-affinity-proteomics
#2
Mattias Brofelth, Lars Wagner Städe, Anna Isinger Ekstrand, Linn Petersson Edfeldt, Rebeka Kovačič, Thorbjørn Terndrup Nielsen, Kim Lambertsen Larsen, Laurent Duroux, Christer Wingren
Recombinant antibody libraries can provide a source of renewable and high-performing binders tailored for use in affinity proteomics. In this context, the process of generating site-specific 1:1 tagging/functionalization and/or orientated surface immobilization of antibodies has, however, proved to be challenging. Hence, novel ways of generating such engineered antibodies for use in affinity proteomics could have a major impact on array performance. In this study, we have further tailored the design of human recombinant scFv antibodies for site-specific photocoupling through the use of an unnatural amino acid (UAA) and the Dock'n'Flash technology...
March 22, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28341988/unexpected-differences-between-planar-and-column-liquid-chromatographic-retention-of-1-acenaphthenol-enantiomers-controlled-by-supramolecular-interactions-involving-%C3%AE-cyclodextrin-at-subambient-temperatures
#3
Hatsuichi Ohta, Elżbieta Włodarczyk, Krzysztof Piaskowski, Aleksandra Kaleniecka, Lucyna Lewandowska, Michał J Baran, Mariusz Wojnicz, Kiyokatsu Jinno, Yoshihiro Saito, Paweł K Zarzycki
We report the results of experimental work focusing on host-guest supramolecular complex creation between macrocyclic compound (β-cyclodextrin) and 1-acenaphthenol enantiomers (racemic mixture) in liquid phase composed of 35% acetonitrile in water (v/v) at different temperatures ranging from 0 to 90 °C. Experimental setup involved several analytical protocols based on classical non-forced flow planar chromatography (RP-18 TLC plates), micro-TLC (RP-18 W HPTLC plates), column chromatography (HPLC with C-18 and C-30 stationary phases), as well as UV-Vis spectrophotometry and optical microscopy...
March 24, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28341986/enhancing-effectiveness-of-capillary-electrophoresis-as-an-analytical-tool-in-the-supramolecular-acidity-modification
#4
Paweł Mateusz Nowak, Michał Woźniakiewicz, Magdalena Janus, Paweł Kościelniak
A strategic modification of acidity (pK a values) by the non-covalent host-guest interactions is one of the most promising concepts in current supramolecular chemistry. This work is aimed at enhancing the effectiveness of capillary electrophoresis (CE) in determination of pK a shifts caused by such interactions and their thermal dependencies crucial in a deep thermodynamic description. We show how to (i) minimize the systematic errors related to Joule heating, (ii) minimize the influence of a voltage ramp time, (iii) speed up pK a shift identification and estimation, (iv) interpret thermal effects related to two overlapped dynamic equilibria, and (v) determine pK a shifts by an alternative spectrophotometric method (CE-DAD)...
March 24, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28340784/separation-of-20-coumarin-derivatives-using-the-capillary-electrophoresis-method-optimized-by-a-series-of-doehlert-experimental-designs
#5
Michał Woźniakiewicz, Marta Gładysz, Paweł M Nowak, Justyna Kędzior, Paweł Kościelniak
The aim of this study was to develop the first CE-based method enabling separation of 20 structurally similar coumarin derivatives. To facilitate method optimization a series of three consequent Doehlert experimental designs with the response surface methodology was employed, using number of peaks and the adjusted time of analysis as the selected responses. Initially, three variables were examined: buffer pH, ionic strength and temperature (No. 1 Doehlert design). The optimal conditions provided only partial separation, on that account, several buffer additives were examined at the next step: organic cosolvents and cyclodextrin (No...
May 15, 2017: Talanta
https://www.readbyqxmd.com/read/28340755/single-molecule-transformation-and-analysis-of-glutathione-oxidized-and-reduced-in-nanopore
#6
Yongfeng Wei, Zhuoqun Su, Xiao-Feng Kang, Yanli Guo, Xiaoxue Mu
The determination of glutathione reduced (GSH) or oxidized (GSSG) in bulk solution has been reported previously. However, it is critically important to set up a simple and label-free method to recognize GSSG and GSH selectively and dynamically, especially at a single-molecule level. Here we report a novel nanopore method to recognize GSSG based on a newly synthesized per-6-quaternary ammonium-β-cyclodextrin (p-QABCD), which is used as both the molecular adaptor of protein nanopore and the recognizing element of GSSG...
May 15, 2017: Talanta
https://www.readbyqxmd.com/read/28340753/fluorometric-detection-of-cholesterol-based-on-%C3%AE-cyclodextrin-functionalized-carbon-quantum-dots-via-competitive-host-guest-recognition
#7
Qian Sun, Siying Fang, Yafen Fang, Zhaosheng Qian, Hui Feng
A sensitive and selective fluorescent method for detection of cholesterol based on β-cyclodextrin functionalized carbon quantum dots (β-CD-CQD) nanoprobe through competitive host-guest recognition has been developed. The bright fluorescence of β-CD-CQD nanoprobe can be effectively quenched by the introduction of a very small amount of p-nitrophenol, and strong quenching ability of p-nitrophenol to the probe was identified. This efficient fluorescence quenching as a static quenching is due to the formation of nonfluorescent complex between β-CD-CQD and p-nitrophenol induced by host-guest interaction between them...
May 15, 2017: Talanta
https://www.readbyqxmd.com/read/28340706/layer-by-layer-self-assembly-of-gold-nanoparticles-thiols-%C3%AE-cyclodextrin-coating-as-the-stationary-phase-for-enhanced-chiral-differentiation-in-open-tubular-capillary-electrochromatography
#8
Lin-Lin Fang, Ping Wang, Xiao-Li Wen, Xin Guo, Lin-da Luo, Jia Yu, Xing-Jie Guo
The popularity of capillary electrochromatography (CEC) has led to an increasing number of studies on the development and evaluation of enantioselective CEC systems. Herein, a novel, simple, and economical method for the preparation of chiral stationary phases for enantioselective open tubular capillary electrochromatography (OTCEC) was reported for the first time. This novel capillary column was fabricated through layer-by-layer self-assembly of GNPs on a 3-mercaptopropyl-trimethoxysilane (MPTMS)-modified fused-silica capillary and subsequent surface functionalization of the GNPs through self-assembly of thiols β-cyclodextrin (SH-β-CD)...
May 15, 2017: Talanta
https://www.readbyqxmd.com/read/28339123/desolution-of-cd-and-cb-macrocycles
#9
Jade A McCune, Susanna Kunz, Magdalena Olesińska, Oren A Scherman
Supramolecular chemistry utilizing the macrocyclic hosts cyclodextrins (CDs) and cucurbit[n]urils (CB[n]s) is traditionally carried out in aqueous media, however, their solubility is typically poor, especially the family of cucurbit[n]urils. Through derivitization of these macrocycles their solubility can be augmented to enable enhanced solubility in water and in some organic solvents. The increase in solubility of these derivitized macrocycles allows for their use in a wider range of chemical environments and giving rise to myriad potential applications...
March 24, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28336842/sers-based-flavonoid-detection-using-ethylenediamine-%C3%AE-cyclodextrin-as-a-capturing-ligand
#10
Jae Min Choi, Eunil Hahm, Kyeonghui Park, Daham Jeong, Won-Yeop Rho, Jaehi Kim, Dae Hong Jeong, Yoon-Sik Lee, Sung Ho Jhang, Hyun Jong Chung, Eunae Cho, Jae-Hyuk Yu, Bong-Hyun Jun, Seunho Jung
Ethylenediamine-modified β-cyclodextrin (Et-β-CD) was immobilized on aggregated silver nanoparticle (NP)-embedded silica NPs (SiO₂@Ag@Et-β-CD NPs) for the effective detection of flavonoids. Silica NPs were used as the template for embedding silver NPs to create hot spots and enhance surface-enhanced Raman scattering (SERS) signals. Et-β-CD was immobilized on Ag NPs to capture flavonoids via host-guest inclusion complex formation, as indicated by enhanced ultraviolet absorption spectra. The resulting SiO₂@Ag@Et-β-CD NPs were used as the SERS substrate for detecting flavonoids, such as hesperetin, naringenin, quercetin, and luteolin...
January 6, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28335503/synthesis-of-randomly-substituted-anionic-cyclodextrins-in-ball-milling
#11
László Jicsinszky, Marina Caporaso, Emanuela Calcio Gaudino, Cristina Giovannoli, Giancarlo Cravotto
A number of influencing factors mean that the random substitution of cyclodextrins (CD) in solution is difficult to reproduce. Reaction assembly in mechanochemistry reduces the number of these factors. However, lack of water can improve the reaction outcomes by minimizing the reagent's hydrolysis. High-energy ball milling is an efficient, green and simple method for one-step reactions and usually reduces degradation and byproduct formation. Anionic CD derivatives have successfully been synthesized in the solid state, using a planetary ball mill...
March 19, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28330240/a-novel-cyclodextrin-glucanotransferase-from-an-alkaliphile-microbacterium-terrae-knr-9-purification-and-properties
#12
Kiransinh N Rajput, Kamlesh C Patel, Ujjval B Trivedi
Cyclodextrin glucanotransferase (CGTase, EC. 2.1.1.19) produced using new alkaliphile Microbacterium terrae KNR 9 has been purified to homogeneity in a single step by the starch adsorption method. The specific activity of the purified CGTase was 45 U/mg compared to crude 0.9 U/mg. This resulted in a 50-fold purification of the enzyme with 33 % yield. The molecular weight of the purified enzyme was found to be 27.72 kDa as determined by SDS-PAGE. Non-denaturing gel electrophoresis and activity staining confirmed the presence of CGTase in crude and the ammonium sulfate precipitate fraction...
December 2016: 3 Biotech
https://www.readbyqxmd.com/read/28329693/lanthanide-integrated-supramolecular-polymeric-nanoassembly-with-multiple-regulation-characteristics-for-multidrug-resistant-cancer-therapy
#13
Weihong Jin, Qiwen Wang, Min Wu, Yang Li, Guping Tang, Yuan Ping, Paul K Chu
Cancer treatment can in principle be enhanced by the synergistic effects of chemo- and nucleic acid-based combination therapies but the lack of efficient drug nanocarriers and occurrence of multidrug resistance (MDR) are major obstacles adversely affecting the effectiveness. Herein, a lanthanide-integrated supramolecular polymeric nanoassembly that delivers anticancer drugs and siRNA for more effective cancer therapy is described. This nanotherapeutic system is prepared by loading adamantane-modified doxorubicin (Dox) into polyethylenimine-crosslinked-γ-cyclodextrin (PC) through the supramolecular assembly to form the interior Dox-loaded PC (PCD) followed by electrostatically driven self-assembly of siRNA and PCD to produce the PCD/siRNA nanocomplexes...
March 16, 2017: Biomaterials
https://www.readbyqxmd.com/read/28328068/separation-of-enilconazole-enantiomers-in-capillary-electrophoresis-with-cyclodextrin-type-chiral-selectors-and-investigation-of-structure-of-selector-selectand-complexes-by-using-nuclear-magnetic-resonance-spectroscopy
#14
Ann Gogolashvili, Elene Tatunashvili, Lali Chankvetadze, Tamas Sohajda, Julianna Szeman, Antonio Salgado, Bezhan Chankvetadze
In the present study the enantiomer migration order (EMO) of enilconazole in the presence of various cyclodextrins (CDs) was investigated by capillary electrophoresis (CE). Opposite EMO of enilconazole were observed when β-CD or the sulfated heptakis(2-O-methyl-3,6-di-O-sulfo)-β-CD (HMDS-β-CD) was used as the chiral selectors. Nuclear Magnetic Resonance (NMR) spectroscopy was used to study the mechanism of chiral recognition between enilconazole enantiomers and those two cyclodextrins. On the basis of rotating frame nuclear Overhauser (ROESY) experiments, the structure of an inclusion complex between enilconazole and β-CD was derived, in which (+)-enilconazole seemed to form a tighter complex than the (-)-enantiomer...
March 22, 2017: Electrophoresis
https://www.readbyqxmd.com/read/28327344/direct-activation-of-ca-2-and-voltage-gated-potassium-channels-of-large-conductance-by-anandamide-in-endothelial-cells-does-not-support-the-presence-of-endothelial-atypical-cannabinoid-receptor
#15
Alexander I Bondarenko, Olga Panasiuk, Iryna Okhai, Fabrizio Montecucco, Karim J Brandt, Francois Mach
Endocannabinoid anandamide induces endothelium-dependent relaxation commonly attributed to stimulation of the G-protein coupled endothelial anandamide receptor. The study addressed the receptor-independent effect of anandamide on large conductance Ca(2+)-dependent K(+) channels expressed in endothelial cell line EA.hy926. Under resting conditions, 10µM anandamide did not significantly influence the resting membrane potential. In a Ca(2+)-free solution the cells were depolarized by ~10 mV. Further administration of 10µM anandamide hyperpolarized the cells by ~8 mV...
March 19, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28326657/ring-shuttling-controls-macroscopic-motion-in-a-three-dimensional-printed-polyrotaxane-monolith
#16
Qianming Lin, Xisen Hou, Chenfeng Ke
Amplification of molecular motions into the macroscopic world has great potential in the development of smart materials. Demonstrated here is an approach that integrates mechanically interlocked molecules into complex three-dimensional (3D) architectures by direct-write 3D printing. The design and synthesis of polypseudorotaxane hydrogels, which are composed of α-cyclodextrins and poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers, and their subsequent fabrication into polyrotaxane-based lattice cubes by 3D printing followed by post-printing polymerization are reported...
March 22, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28326558/hemocd-as-a-totally-synthetic-artificial-oxygen-carrier-improvements-in-the-synthesis-and-o2-co-discrimination
#17
Hiroaki Kitagishi, Qiyue Mao, Naoya Kitamura, Takahiro Kita
HemoCD, which is composed of an iron(II)porphyrin such as 5,10,15,20-tetrakis(4-sulfonatophenyl)porphinatoiron(II) (Fe(II)TPPS) and a cyclodextrin (CD) dimer having a pyridine linker, represents a synthetic hemoglobin (Hb) model compound that exhibits reversible oxygen (O2 ) binding ability in aqueous solution at an ambient temperature. Therefore, hemoCD has the potential to be used as a totally synthetic artificial oxygen carrier. In this article, we describe the improvements of hemoCD related to its synthesis and O2 /CO selectivity...
March 22, 2017: Artificial Organs
https://www.readbyqxmd.com/read/28325685/a-positive-feedback-strategy-for-enhanced-chemotherapy-based-on-ros-triggered-self-accelerating-drug-release-nanosystem
#18
Jing-Jing Hu, Qi Lei, Meng-Yun Peng, Di-Wei Zheng, Yi-Xuan Chen, Xian-Zheng Zhang
Here, a positive feedback strategy was utilized to amplify the concentration of intracellular reactive oxygen species (ROS) and a ROS-triggered self-accelerating drug release nanosystem (defined as T/D@RSMSNs) was demonstrated for enhanced tumor chemotherapy. The mesoporous silica nanoparticles (MSNs) based nanocarriers were gated by β-cyclodextrin (β-CD) through the ROS-cleavable thioketal (TK) linker to encapsulate the anticancer drug doxorubicin hydrochloride (DOX) and ROS producing agent α-tocopheryl succinate (α-TOS), whose surface was further anchored with adamantane conjugated poly(ethylene glycol) chain (AD-PEG) via host-guest interaction...
March 11, 2017: Biomaterials
https://www.readbyqxmd.com/read/28325342/cyclodextrin-based-sustained-and-controllable-release-system-of-insulin-utilizing-the-combination-system-of-self-assembly-pegylation-and-polypseudorotaxane-formation
#19
Tatsunori Hirotsu, Taishi Higashi, Keiichi Motoyama, Hidetoshi Arima
Sustained and controllable release of insulin is strongly required to achieve the ideal treatment of diabetes. We previously developed "self-assembly PEGylation retaining activity (SPRA) technology" via a host-guest interaction between PEGylated β-cyclodextrin and adamantane-appended insulin, and resulting PEGylated insulin was termed SPRA-insulin. So far, we also demonstrated that covalently PEGylated insulin forms polypseudorotaxanes (PPRXs) with cyclodextrins (PPRX technology). In the present study, we designed and evaluated the combination system of SPRA technology and PPRX technology to achieve a sustained and controllable release system of insulin...
May 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28325339/toward-novel-antiparasitic-formulations-complexes-of-albendazole-desmotropes-and-%C3%AE-cyclodextrin
#20
Ana K Chattah, Laura Y Pfund, Ariana Zoppi, Marcela R Longhi, Claudia Garnero
Novel complexes of two different solid forms of Albendazol and β-cyclodextrin were investigated in an attempt to obtain promising candidates for the preparation of alternative matrices used in pharmaceutical oral formulations. The interaction between each form of Albendazol and β-cyclodextrin was studied in solution and solid state, in order to investigate their effect on the solubility and dissolution rate of Albendazol solid forms. The solid supramolecular systems were characterized using a variety of techniques including natural-abundance (13)C cross-polarization magic-angle-spinning nuclear magnetic resonance, powder X-ray diffraction, Fourier transform-infrared spectroscopy and scanning electron microscopy...
May 15, 2017: Carbohydrate Polymers
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