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Methyl cyclodextrin

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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/28341986/enhancing-effectiveness-of-capillary-electrophoresis-as-an-analytical-tool-in-the-supramolecular-acidity-modification
#2
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
#3
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/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
#4
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
#5
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/28322010/cholesterol-can-modulate-mitochondrial-aquaporin-8-expression-in-human-hepatic-cells
#6
Mauro Danielli, Alejo M Capiglioni, Julieta Marrone, Giuseppe Calamita, Raúl A Marinelli
Hepatocyte mitochondrial aquaporin-8 (mtAQP8) works as a multifunctional membrane channel protein that facilitates the uptake of ammonia for its detoxification to urea as well as the mitochondrial release of hydrogen peroxide. Since early oligonucleotide microarray studies in liver of cholesterol-fed mice showed an AQP8 downregulation, we tested whether alterations of cholesterol content per se modulate mtAQP8 expression in human hepatocyte-derived Huh-7 cells. Cholesterol loading with methyl-β-cyclodextrin (mβCD):cholesterol complexes downregulated the proteolytic activation of cholesterol-responsive sterol regulatory element-binding protein (SREBP) transcriptions factors 1 and 2, and the expression of the target gene 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR)...
March 20, 2017: IUBMB Life
https://www.readbyqxmd.com/read/28315482/modes-of-antibacterial-action-of-curcumin-under-dark-and-light-conditions-a-toxicoproteomics-approach
#7
Ilya Shlar, Samir Droby, Victor Rodov
Curcumin is a potent natural food-grade antimicrobial compound. Exposure to light further enhances its antimicrobial capacity. Proteomic methods were used in this study for investigating the mechanistic aspects of the antibacterial curcumin effects in the dark and upon illumination. Escherichia coli cells exposed to water-dispersible curcumin-methyl-β-cyclodextrin inclusion complex under dark and light conditions were compared with the non-treated cells kept under the same illumination regimes. Curcumin treatment in the dark evoked adaptive responses aimed at mitigation of oxidative stress, DNA protection, proteostasis, modulation of redox state via changing NADH level, and gasotransmitter (H2S and NH3) biosynthesis...
March 14, 2017: Journal of Proteomics
https://www.readbyqxmd.com/read/28302970/modified-radical-scavenging-and-antioxidant-activity-measurement-of-%C3%AE-carotene-with-%C3%AE-cyclodextrins-complexation-in-aqueous-medium
#8
Saliha Esin Çelik, Burcu Bekdeser, Ayse Nur Tufan, Resat Apak
In order to evaluate the antioxidant capacity/activity of β-carotene (BC) in aqueous media, we investigated the inclusion complexes of BC with methyl-β-cyclodextrin (Me-β-CD), 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and 2-hydroxyethyl-β-cyclodextrin (HE-β-CD) that enhance water solubility and chemical stability. The inclusion complexes (monitored by FTIR) exhibited higher solubility than free BC, and phase solubility studies showed a linear increase in the solubility with the Me-β-CD concentration...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
https://www.readbyqxmd.com/read/28279932/enantioselective-recognition-of-radezolid-by-cyclodextrin-modified-capillary-electrokinetic-chromatography-and-electronic-circular-dichroism
#9
Katarzyna Michalska, Ewa Gruba, Wojciech Bocian, Judyta Cielecka-Piontek
A method for the enantioseparation of radezolid (RAD), an analogue of a truly new class of antibacterial agents, oxazolidinones, was developed based on capillary electrokinetic chromatography using a cyclodextrin as a chiral pseudophase (CD-cEKC). The mechanism of RAD separation, together with its precursor, were investigated to directly define the relationship between the oxazolidinone structure and the complexation process. During the development of the method, anionic single isomer cyclodextrins were tested...
February 21, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28257814/synthesis-and-characterization-of-a-novel-rhodamine-labeled-cholesterol-reporter
#10
Alexander Maiwald, Olivia Bauer, Gerald Gimpl
We introduce the novel fluorescent cholesterol probe RChol in which a sulforhodamine group is linked to the sixth carbon atom of the steroid backbone of cholesterol. The same position has recently been selected to generate the fluorescent reporter 6-dansyl-cholestanol (DChol) and the photoreactive 6-azi-cholestanol. In comparison with DChol, RChol is brighter, much more photostable, and requires less energy for excitation, i.e. favorable conditions for microscopical imaging. RChol easily incorporates into methyl-β-cyclodextrin forming a water-soluble inclusion complex that acts as an efficient sterol donor for cells and membranes...
February 28, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28256617/cholesterol-depletion-impairs-contractile-machinery-in-neonatal-rat-cardiomyocytes
#11
Barbara Hissa, Patrick W Oakes, Bruno Pontes, Guillermina Ramírez-San Juan, Margaret L Gardel
Cholesterol regulates numerous cellular processes. Depleting its synthesis in skeletal myofibers induces vacuolization and contraction impairment. However, little is known about how cholesterol reduction affects cardiomyocyte behavior. Here, we deplete cholesterol by incubating neonatal cardiomyocytes with methyl-beta-cyclodextrin. Traction force microscopy shows that lowering cholesterol increases the rate of cell contraction and generates defects in cell relaxation. Cholesterol depletion also increases membrane tension, Ca(2+) spikes frequency and intracellular Ca(2+) concentration...
March 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28236056/influence-of-membrane-receptor-lateral-diffusion-on-the-short-term-depression-of-acetylcholine-induced-current-in-helix-neurons
#12
Natalia A Vasilyeva, Galina B Murzina, Igor I Kireev, Arkady S Pivovarov
We have studied how various drugs increasing the rate of nicotinic acetylcholine receptors (nAChRs) lateral diffusion affect the depression of ACh-induced current in land snail Helix lucorum neurons responsible for defensive behavior. The acetylcholine (ACh) iontophoretic application protocol imitated the behavioral habituation protocol for the intact animal. We found that the drugs decreasing cholesterol level in cell membranes as methyl-β-cyclodextrin 1 mM and Ro 48-8071 2 µM, and polyclonal antibodies to actin-binding proteins as spectrin 5 µg/ml and merlin 2...
February 24, 2017: Cellular and Molecular Neurobiology
https://www.readbyqxmd.com/read/28214727/a-new-strategy-to-enhance-the-biosynthesis-of-trans-resveratrol-by-overexpressing-stilbene-synthase-gene-in-elicited-vitis-vinifera-cell-cultures
#13
Mingyu Chu, M A Pedreño, Nuria Alburquerque, Lydia Faize, Lorenzo Burgos, Lorena Almagro
In this work, transgenic lines of suspension cultured cells of Vitis vinifera cv. Monastrell containing the plasmid pMOG800-sts have been obtained. The cell growth of these transgenic cell lines decreased slightly as compared to non-transgenic suspension cultured cells, while cell viability was not affected. In addition, the elicitation with cyclodextrins and methyl jasmonate enhanced the production of trans-resveratrol, observing the highest levels of this compound in sts-expressing transgenic Vitis suspension cultured cells with the sts expression cassette in the forwards orientation...
February 8, 2017: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/28213944/separation-of-hydroxynorketamine-stereoisomers-using-capillary-electrophoresis-with-sulfated-%C3%AE-cyclodextrin-and-highly-sulfated-%C3%AE-cyclodextrin
#14
Friederike A Sandbaumhüter, Regula Theurillat, Wolfgang Thormann
The racemic N-methyl-d-aspartate receptor antagonist ketamine is used in anesthesia, analgesia and the treatment of depressive disorders. It is known that interactions of hydroxylated norketamine metabolites and 5,6-dehydronorketamine (DHNK) with the α7 -nicotinic acetylcholine receptor and the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor are responsible for the antidepressive effects. Ketamine and its first metabolite norketamine are not active on these receptors. As stereoselectivity plays a role in ketamine metabolism, a cationic capillary electrophoresis based method capable of resolving and analyzing the stereoisomers of four hydroxylated norketamine metabolites, norketamine and DHNK was developed...
February 18, 2017: Electrophoresis
https://www.readbyqxmd.com/read/28205316/novel-polymeric-monolith-materials-with-a-%C3%AE-cyclodextrin-graphene-composite-for-the-highly-selective-extraction-of-methyl-jasmonate
#15
Xinhong Yu, Xu Ling, Li Zou, Zilin Chen
A novel polymeric monolith column with a β-cyclodextrins-graphene composite was prepared for extraction of methyl jasmonate. A simple, sensitive and effective polymeric monolith microextraction with high-performance liquid chromatography method has been presented for the determination. To carry out the best microextraction efficiency, several parameters such as sample flow rate, sample volume and sample pH value were systematically optimized. In addition, the method validation showed a wide linear range of 5-2000 ng mL(-) ¹, with a good linearity and the low limits of detection for methyl jasmonate...
February 16, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28204818/reactive-oxygen-species-mediate-angiotensin-ii-induced-transcytosis-of-low-density-lipoprotein-across-endothelial-cells
#16
Fang Bian, Jun Cui, Tao Zheng, Si Jin
The retention of plasma low-density lipoprotein (LDL) particles to subendothelial spaces through transcytosis across the endothelium is the initial step of atherosclerosis (AS). Angiotensin II (Ang II), as the principal effector molecule of the renin-angiotensin system (RAS), is implicated in several important steps of AS development. However, whether or not Ang II can directly exert a pro‑atherogenic effect by promoting LDL transcytosis across endothelial barriers, has not been defined. In the present study, we found that Ang II upregulated intracellular reactive oxygen species (ROS) levels in endothelial cells (ECs) by measuring fluorescence of 2',7'-dichlorofluorescein (DCF‑DA)...
March 2017: International Journal of Molecular Medicine
https://www.readbyqxmd.com/read/28203712/fertility-of-cold-stored-mouse-sperm-is-recovered-by-promoting-acrosome-reaction-and-hyperactivation-after-cholesterol-efflux-by-methyl-beta-cyclodextrin
#17
Hidetaka Yoshimoto, Toru Takeo, Tetsumi Irie, Naomi Nakagata
No abstract text is available yet for this article.
February 1, 2017: Biology of Reproduction
https://www.readbyqxmd.com/read/28194311/tracking-the-virus-like-particles-of-macrobrachium-rosenbergii-nodavirus-in-insect-cells
#18
Ummi Fairuz Hanapi, Chean Yeah Yong, Zee Hong Goh, Noorjahan Banu Alitheen, Swee Keong Yeap, Wen Siang Tan
Macrobrachium rosenbergii nodavirus (MrNv) poses a major threat to the prawn industry. Currently, no effective vaccine and treatment are available to prevent the spread of MrNv. Its infection mechanism and localisation in a host cell are also not well characterised. The MrNv capsid protein (MrNvc) produced in Escherichia coli self-assembled into virus-like particles (VLPs) resembling the native virus. Thus, fluorescein labelled MrNvc VLPs were employed as a model to study the virus entry and localisation in Spodoptera frugiperda, Sf9 cells...
2017: PeerJ
https://www.readbyqxmd.com/read/28185959/improving-the-dissolution-properties-of-curcumin-using-dense-gas-antisolvent-technology
#19
Firman Kurniawansyah, Lisa Quachie, Raffaella Mammucari, Neil R Foster
The dissolution properties of curcumin are notoriously poor and hinder its bioavailability. To improve its dissolution properties, curcumin has been formulated with methyl-β-cyclodextrin and polyvinylpyrrolidone by the atomized rapid injection solvent extraction (ARISE) system. The compounds were co-precipitated from organic solutions using carbon dioxide at 30°C and 95bar as the antisolvent. Curcumin formulations were also produced by physical mixing and freeze drying for comparative purposes. The morphology, crystallinity, solid state molecular interactions, apparent solubility and dissolution profiles of samples were observed...
February 6, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28184226/clathrin-in-chara-australis-molecular-analysis-and-involvement-in-charasome-degradation-and-constitutive-endocytosis
#20
Marion C Hoepflinger, Margit Hoeftberger, Aniela Sommer, Christina Hametner, Ilse Foissner
Charasomes are convoluted plasma membrane domains in characean green algae. They are known to form in response to light via secretion of trans-Golgi network (TGN) vesicles and local inhibition of endocytosis. Charasomes are involved in the acidification of their aqueous environment, thereby facilitating photosynthesis-dependent carbon uptake. Charasome formation is reversible to allow cells to adapt to different light conditions. Here, we show that darkness-induced degradation of charasomes involves the formation of coated pits and coated vesicles...
2017: Frontiers in Plant Science
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