Introduction: It is important to confirm the effectiveness and tolerability of disease-modifying treatments for relapsing-remitting multiple sclerosis (RRMS) in real-world treatment settings. This prospective observational cohort study (VIRGILE) was performed at the request of the French health authorities. The primary objective was to evaluate the effectiveness of fingolimod 0.
View Article and Find Full Text PDFd-Amino acid oxidase (DAAO) is a potential target in the treatment of schizophrenia as its inhibition increases brain d-serine level and thus contributes to NMDA receptor activation. Inhibitors of DAAO were sought testing [6+5] type heterocycles and identified isatin derivatives as micromolar DAAO inhibitors. A pharmacophore and structure-activity relationship analysis of isatins and reported DAAO inhibitors led us to investigate 1H-indazol-3-ol derivatives and nanomolar inhibitors were identified.
View Article and Find Full Text PDFApplication of nanoscale materials (NMs) displays a rapidly increasing trend in electronics, optics, chemical catalysis, biotechnology, and medicine due to versatile nature of NMs and easily adjustable physical, physicochemical, and chemical properties. However, the increasing abundance of NMs also poses significant new and emerging health and environmental risks. Despite growing efforts, understanding toxicity of NMs does not seem to cope with the demand, because NMs usually act entirely different from those of conventional small molecule drugs.
View Article and Find Full Text PDFSpectroscopic studies combined with computational analysis indicate the inherent conformational flexibility of the β-carbolin derivative evodiamine (EVD) featured with diverse pharmacological activities. Qualitative evaluation of the circular dichroism (CD) spectra of EVD enantiomers complemented with quantum chemical calculations reveals a chiral exciton signature that can be assigned to the folded, L-shaped conformation of the molecule. Changes of the exciton couplet measured in different solvents and the near-UV CD profile upon binding to human serum albumin (HSA) refer to the structural adaptability of EVD.
View Article and Find Full Text PDFThe resolution power of permethylated 6-monoamino-6-monodeoxy-βCD (PMMABCD) - a single isomer, cationic CD derivative - developed previously for chiral analyses in capillary electrophoresis was further studied here. Dansylated amino acids (Dns-AA) were chosen as amphoteric chiral model compounds. Changes in the resolutions of Dns-AAs by varying pH and selector concentrations were investigated and correlated with their structures and chemical properties (isoelectric point and lipophilicity).
View Article and Find Full Text PDFA method has been developed to encapsulate bovine serum albumin (BSA)-coated gold quantum clusters (AuQC@BSA) in a multilamellar system of dipalmitoylphosphatidylcholine (DPPC). Results have shown that intercalation of AuQC@BSA particles into lipid bilayers occurs in the presence of CaCl2. Intense red photoluminescence emission was observed after encapsulation of the clusters.
View Article and Find Full Text PDFInfluence of acid concentration in the mobile phase on protein separation was studied in a wide concentration range using trifluoroacetic acid (TFA) and formic acid (FA). At low, 0.001-0.
View Article and Find Full Text PDFEnantioselective capillary electrophoretic methods were elaborated for the determination of the enantiomeric purity of (R)-MDL 100,907 and its preparatively resolved key intermediate compound during the synthesis route. The pKa values of the intermediate compound and the end product determined by CE were 10.5±0.
View Article and Find Full Text PDFHarmane and norharmane are representative members of the large group of natural β-carboline alkaloids featured with diverse pharmacological activities. In blood, these agents are transported by human serum albumin (HSA) which has a profound impact on the pharmacokinetic and pharmacodynamic properties of many therapeutic drugs and xenobiotics. By combination of various spectroscopic methods, the present contribution is aimed to elucidate how nonesterified fatty acids (FAs), the primary endogenous ligands of HSA, affect the binding properties of harmane and norharmane.
View Article and Find Full Text PDFNovel N-hydroxyalkyl-2-aminophenothiazines implying a tetrazole moiety at the alkyl chain have been synthesized by hydroboration-oxidation of dienes followed by Buchwald-Hartwig cross-coupling reaction. Also, some sulfoxide and sulfone derivatives have been prepared by selective oxidations. MDR inhibition studies on rat hepatocyte cell culture revealed that some derivatives exhibit marked biological efficacy exceeding that of the standard verapamil (e.
View Article and Find Full Text PDFJ Nanobiotechnology
April 2013
Background: The potential nanocarrier polyamidoamine (PAMAM) generation 5 (G5-NH(2)) dendrimer has been shown to evoke lasting neuronal depolarization and cell death in a concentration-dependent manner. In this study we explored the early progression of G5-NH(2) action in brain tissue on neuronal and astroglial cells.
Results: In order to describe early mechanisms of G5-NH(2) dendrimer action in brain tissue we assessed G5-NH(2) trafficking, free intracellular Ca(2+) and mitochondrial membrane potential (Ψ(MITO)) changes in the rat hippocampal slice by microfluorimetry.
New carotenoids, cryptocapsin-5,6-epoxide, 3'-deoxycapsanthin-5,6-epoxide, and cryptocapsin-5,8-epoxides, have been isolated from the ripe fruits of red mamey (Pouteria sapota). Cryptocapsin-5,6-epoxide was prepared by partial synthesis via epoxidation of cryptocapsin, and the (5R,6S)- and (5S,6R)-stereoisomers were identified by HPLC-ECD analysis. Spectroscopic data of the natural (anti) and semisynthetic (syn) derivatives obtained by acid-catalyzed rearrangement of cryptocapsin-5,8-epoxide stereoisomers were compared for structural elucidation.
View Article and Find Full Text PDFInclusion complexes of warfarin enantiomers with permethylated monoamino-β-cyclodextrin (PMMABCD) were characterized using CE and (1)H NMR spectroscopy in aqueous solution. These techniques gave complementary information on the stability and the structure of the diastereomeric host-guest inclusion complexes. The stability constants were determined from CE experiments in a wide pH range.
View Article and Find Full Text PDFThree β-cyclodextrin-based chiral stationary phases were developed applying novel bonding chemistry. The separation performances of β-cyclodextrin, (R,S)-2-hydroxypropyl-β-cyclodextrin, and permethyl-β-cyclodextrin-based CSPs were compared in the resolution of structurally divergent analytes, such as coumarins, dansyl amino acids, and propionic acid derivatives. Separations were carried out in reversed phase mode applying 0.
View Article and Find Full Text PDFSeven diastereomer pairs of tetrapeptide analogues (TP) of endomorphin-1 and -2 were synthesized. A stereoselective capillary electrophoretic method was developed for controlling stereoisomeric ratio or purity. The isoelectric points of the tetrapeptides were between 8.
View Article and Find Full Text PDFInt J Biol Macromol
April 2012
Imatinib (IMT) is a selective tyrosine kinase inhibitor, used in the treatment of chronic myeloid leukemia and gastrointestinal stromal tumors. Its strong plasma protein binding was found to belong to the F1*S genetic variant of α(1)-acid glycoprotein (AGP). In this work, comparative AGP binding studies were performed with IMT fragment molecules to reveal which parts of the molecule are important in the high-affinity interaction provoking specific spectral changes.
View Article and Find Full Text PDFWe report for the first time on neuronal signaling for the evaluation of interactions between native plasmamembrane and polyamidoamine (PAMAM) dendrimers. Generation 5 polycationic (G5-NH(2)), novel β-D-glucopyranose-conjugated G5-NH(2) and generation 4.5 polyanionic (G4.
View Article and Find Full Text PDFCapillary electrophoresis (CE) methods for chiral resolution of five antimalarial drugs (primaquine, tafenoquine, mefloquine, chloroquine and quinacrine) were developed by using a wide selection of neutral and anionic cyclodextrin (CD) derivatives. The use of sulfobutyl-β-CD and carboxymethyl-β-CD (CMBCD) resulted in good resolution of quinacrine and tafenoquine, respectively. New results are presented for resolutions of chloroquine and mefloquine.
View Article and Find Full Text PDFChiral separation of 19 pairs of cis-beta-lactam (BL) stereoisomers of pharmacological importance was examined by capillary electrophoresis using cyclodextrin (CD) derivatives. In order to select the most effective conditions separating the highest number of stereoisomers of BLs, single carboxymethyl alpha-, beta- and gamma-, as well as sulfobutyl beta-CD derivatives were applied. Additionally, carboxymethyl and sulfobutyl beta-CD derivatives complemented with neutral beta-CD derivatives as dual CD systems were tested.
View Article and Find Full Text PDFPreparation of (6-monoureido-6-monodeoxy) permethylated beta-cyclodextrin bonded chiral stationary phase from permethylated 6-monoamino-6-monodeoxy-beta-cyclodextrin is described. The optimized chiral stationary phase was evaluated by using HPLC separation of racemates of coumarin derivatives. Column characterization was performed by solid-state (13)C, (15)N, (29)Si NMR using cross-polarization at the magic angle spinning.
View Article and Find Full Text PDFBackground: alpha(1)-Acid glycoprotein (AGP) plays a decisive role in the serum protein binding of several drugs.Genetic variants of AGP have different ligand binding properties. The binding of deramciclane (DER), a chiral anxiolytic agent, has been studied on A and F1/S genetic variants of AGP.
View Article and Find Full Text PDFGamma-hydroxybutyric acid (GHB) binding to multiple sites for the tricarboxylic acid cycle intermediate succinic acid (SUC) has been disclosed recently. In order to better characterize these targets, distinguishable binding of GHB receptor-specific NCS 382 antipodes to [(3)H]-SUC or [(3)H]-GHB labelled sites in rat brain synaptic membranes was explored. Eutomer binding parameters suggest identity of the high-affinity target for SUC with a synaptic GHB receptor subtype.
View Article and Find Full Text PDFIn order to explore the molecular interaction between cyclothiazide (CTZ) and gamma-aminobutyric acidA (GABAA) receptors, possibly underlying inhibition of GABAA receptor currents, [3H]-CTZ was synthesized. Binding of [3H]-CTZ to rat brain synaptic membranes could be observed only in the presence of the GABAA receptor antagonist (-)[1S,9R]-bicuculline methiodide (BMI) (EC(50,BMI)=500+/-80microM). GABA decreased [(3)H]-CTZ binding induced by the presence 300microM and 3mM BMI with IC(50,GABA) values of 300+/-50microM and 5.
View Article and Find Full Text PDFHuman plasma protein binding of six antimalarial agents of quinoline and acridine types was investigated by using spectroscopic techniques, affinity chromatography, ultrafiltration and HPLC methods. Induced circular dichroism (ICD) spectra showed binding of amodiaquine (AMQ), primaquine (PRQ), tafenoquine (TFQ), and quinacrine (QR) to alpha(1)-acid glycoprotein (AAG), the serum level of which greatly increases in Plasmodium infections. Association constant (K(a)) values of about 10(5)-10(6) M(-1) could be determined.
View Article and Find Full Text PDFDiazepam, a 1,4-benzodiazepine lacking chiral centre, exists in an equimolar mixture of two chiral conformers. Induced circular dichroism spectra for the binding of diazepam and its 3,3-dimethyl substituted analogues to alpha1-acid glycoprotein (AGP) revealed that opposite to human serum albumin, AGP preferably binds the P-conformers. Accordingly, slightly favoured binding of (R)-enantiomers of 3-alkyl derivatives having P-conformation was found.
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