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10768355 | Simultaneous determination of alpha, beta and gamma cyclodextrins by LC. | Cyclodextrins (CDs) can be synthesized from starch by cyclodextrin glycosyltransferase (CGTase). This enzyme produces alpha-, beta- and gamma-CDs in varying proportions. In the production of cyclodextrins, purity as well as yield are important factors. A precise and reproducible method was developed and validated for t... |
10756200 | Accurate and rapid modeling of iron-bleomycin-induced DNA damage using tethered duplex oligonucleotides and electrospray ionization ion trap mass spectrometric analysis. | Bleomycin B(2)(BLM) in the presence of iron [Fe(II)] and O(2)catalyzes single-stranded (ss) and double-stranded (ds) cleavage of DNA. Electrospray ionization ion trap mass spectrometry was used to monitor these cleavage processes. Two duplex oligonucleotides containing an ethylene oxide tether between both strands were... |
10756032 | Dysregulation of cyclin E gene expression in human cytomegalovirus-infected cells requires viral early gene expression and is associated with changes in the Rb-related protein p130. | We have previously shown that many cell cycle regulatory gene products are markedly affected by infection of primary fibroblasts with human cytomegalovirus (HCMV) (F. M. Jault, J. M. Jault, F. Ruchti, E. A. Fortunato, C. Clark, J. Corbeil, D. D. Richman, and D. H. Spector, J. Virol. 69:6697-6704, 1995). One of these pr... |
10756008 | Clinical isolates of measles virus use CD46 as a cellular receptor. | Laboratory strains of measles viruses (MV), such as Edmonston and Halle, use the complement regulatory protein CD46 as a cell surface receptor. The receptor usage of clinical isolates of MV, however, remains unclear. Receptor usage by primary patient isolates of MV was compared to isolates that had been passaged on a v... |
10756007 | Roles of adeno-associated virus Rep protein and human chromosome 19 in site-specific recombination. | Adeno-associated virus type 2 (AAV) is the only known eucaryotic virus capable of targeted integration in human cells. AAV integrates preferentially into human chromosome (ch) 19q13.3qter. The nonstructural proteins of AAV-2, Rep78 and Rep68, are essential for targeted integration. Rep78 and Rep68 are multifunctional p... |
10749380 | Structural macromolecules and supramolecular organisation of the vitreous gel. | The vitreous gel is a transparent extracellular matrix that fills the cavity behind the lens of the eye and is surrounded by and attached to the retina. This gel liquefies during ageing and in 25-30% of the oppulation the residual gel structure eventually collapses away from the posterior retina in a process called pos... |
10742586 | Controlled release of a water-soluble drug, captopril, by a combination of hydrophilic and hydrophobic cyclodextrin derivatives. | Parent beta-cyclodextrin (beta-CyD) and 2-hydroxypropyl-beta-CyD (HP-beta-CyD) form 1:1 solid complexes with an orally active angiotensin-converting enzyme inhibitor, captopril, while hydrophobic perbutanoyl-beta-CyD (TB-beta-CyD) forms a solid dispersion or solid solution with the drug. The binary system of captopril/... |
10735464 | Application of membrane-based dendrimer/DNA complexes for solid phase transfection in vitro and in vivo. | In this study a general description of the use of solid support membranes as the device for DNA delivery mediated by PAMAM dendrimers is presented. In contrast to the other DNA carriers, dendrimer/DNA complexes retain the ability to transfect after drying, which enabled coating or incorporation of complexes into poly(D... |
11104520 | Molecular mechanisms of spindle function. | The key molecules involved in regulating the assembly and function of the mitotic spindle are shared by evolutionarily divergent species. Studies in different model systems are leading to convergent conclusions about the central role of microtubule nucleation and dynamics and of kinesin-related motor proteins in spindl... |
22791931 | Activity of Novel Adenine Nucleotide Derivatives as Agonists and Antagonists at Recombinant Rat P2X Receptors. | Strategy, Management and Health PolicyVenture Capital Enabling TechnologyPreclinical ResearchPreclinical Development Toxicology, Formulation Drug Delivery, PharmacokineticsClinical Development Phases I-III Regulatory, Quality, ManufacturingPostmarketing Phase IVThe effects of structural modifications of adenine nucleot... |
18967926 | Optimization of the room-temperature phosphorescence of the 6-bromo-2-naphthol-alpha-cyclodextrin system in aqueous solution. | The influence of different factors on the room-temperature phosphorescence (RTP) emission from the inclusion complex between alpha-cyclodextrin (alpha-CD) and 6-bromo-2-naphthol (BN) was analyzed. Although RTP signals are detected even in aerated solutions, an efficient enhancement of the phosphorescence emission (abou... |
18967933 | beta-Cyclodextrin-ferrocene inclusion complex modified carbon paste electrode for amperometric determination of ascorbic acid. | Inclusion complex of ferrocene (Fc) with beta-cyclodextrin (beta-CD) has been synthesized in ethylene glycol. It was unsolvable in water and had been successfully used to the preparation of beta-CD-Fc inclusion complex modified carbon paste electrode (CFCPE). Solid paraffin was used as the binder of the electrode. Asco... |
18967896 | Equilibrium studies on complexation in water and solvent extraction of zinc(II) and cadmium(II) with benzo-18-crown-6. | The formation constants (K(ML)) in water of 1:1 complexes of benzo-18-crown-6 (B18C6) and 18-crown-6 (18C6) with Zn(2+) and Cd(2+), the sizes of which are much smaller than the ligand cavities, were determined at 25 degrees C by conductometry. Compared with Cd(2+), the crown ethers form more stable complexes with Zn(2+... |
10840966 | Diagnostic organometallic and metallodendritic materials for SO2 gas detection: reversible binding of sulfur dioxide to arylplatinum(II) complexes | A series of square-planar platinum(II) complexes of the N,C,N'-terdentate-coordinating monoanionic "pincer" ligand, [PtX(4-E-2,6-[CH2NRR']2-C6H2](X=Cl, Br, I, tolyl; R, R'=Et, Me; E=H, OH, OSiMe2tBu) has been prepared. In the presence of sulfur dioxide, these complexes spontaneously adsorb this gas to form penta-coordi... |
10840961 | Facilitated transport of salts by neutral anion carriers | Partitioning of ions from water to the membrane solvent (NPOE) can be quantified by Gibbs free energies of transfer, deltaG(tr,NPOE)(ion). These were derived from transport studies of lipophilic salts through supported liquid membranes (SLMs) in the absence of the carrier. Partition coefficients Kp for various salts ca... |
10840957 | Quantitative chirality/enantioselectivity relations in large random supramolecular structures | We study the relationship between shape and enantioselectivity, employing quantitative geometric chirality measurements. The model we use comprises of the boundary surfaces of two-dimensional (2D) chiral, large, random selectors (diffusion limited aggregates), interacting with homologous series of small 2D-chiral S-sha... |
10840955 | STM imaging of a heptanuclear ruthenium(II) dendrimer, mono-add layer on graphite | Scanning tunneling microscopy (STM) and molecular mechanics calculations were used to investigate the long-range packing and the structure of an heptanuclear ruthenium (II) dendritic species, as a PF6- salt. STM imaging was carried out on a mono-add layer of the ruthenium dendrimer formed by physisorption from a 1,2,4-... |
10804553 | Supramolecular phthalocyanine dimers based on the secondary dialkylammonium cation/dibenzo-24-crown-8 recognition motif | [formula: see text] New unsymmetrically substituted DB24C8-phthalocyanines, which are able to form complexes with suitable dialkylammonium cations, have been prepared. These complexes most probably have a pseudorotaxane geometry. |
10804542 | A conformationally reliable spacer for molecular tweezers | [figure: see text] A reliable and rigid spacer, trans,trans,trans-perhydronaphthacene, for molecular tweezers was designed. A synthesis and molecular recognition study of its 1,14-disubstituted derivatives was carried out. |
10794286 | Structure of the inclusion complex of beta-cyclodextrin with 1,12-dodecanedioic acid using synchrotron radiation data; a detailed dimeric beta-cyclodextrin structure | A detailed crystal structure study of the dimeric inclusion complex of beta-cyclodextrin (betaCD) with 1,12-dodecanedioic acid is presented [IUPAC name: beta-cyclodextrin-1,12-dodecanedioic acid (2/1)]. The structure was solved with synchrotron high-resolution data (0.65 A) at 100 K [crystal data: P1, Z= 1, a = 18.153 ... |
10794282 | 3,6,9,16,19,22-Hexaazatricyclo | The adduct (1) formed between the hexaaza macrocycle 3,6,9,16,19,22-hexaazatricyclo[22.2.2.2(11,14]triconta-1(26),11(29),12,14(30),24,27-hexaene, C24H38N6, and 4,4'-sulfonyldiphenol, O2S(C6H4OH)2, is a salt [(C24H40N6)2+].2[(HOC6H4SO2C6H4O)-], and the adduct (2) formed by the same macrocyclic amine with 4,4'-biphenol i... |
10794281 | Oligosiloxanediols as building blocks for supramolecular chemistry: hydrogen-bonded adducts with amines form supramolecular structures in zero, one and two dimensions | The structure of 1,1,3,3,5,5-hexaphenyltrisiloxane-1,5-diol-pyrazine (4/1), (C36H32O4Si3)4.C4H4N2 (1), contains finite centrosymmetric aggregates; the diol units form dimers, by means of O-H...O hydrogen bonds, and pairs of such dimers are linked to the pyrazine by means of O-H...N hydrogen bonds. In 1,1,3,3,5,5-hexaph... |
10794280 | Hydrogen-bonding behaviour of benzene-1,2,4,5-tetracarboxylic acid: supramolecular structures of different dimensionality in the 2:1 adducts formed with 4,4'-bipyridyl and hexamethylenetetramine | Co-crystallization of benzene-1,2,4,5-tetracarboxylic acid, C10H6O8, with 4,4'-bipyridyl, C10H8N2, or with hexamethylenetetramine, C6H12N4, from methanol solutions yields in each case a 2:1 salt, [(C10H9N2)+]2.[(C10H4O8)2-] (1) and [(C6H13N4)+]2.[(C10H4O8)2-] (2). In (1) the carboxylate anions lie across centres of inv... |
10789450 | Synthesis and metal ion complexation studies of proton-ionizable calix | A series of novel N-chromogenic calix[4]arene azacrown ethers were synthesized as selective extractants of potassium ion. 1,3-Alternate calix[4]arene azacrown ethers were prepared by reacting 25,27-dipropyloxy-26,28-bis(5-chloro-3-oxapentyloxy) calix[4]arenes with p-toluenesulfonamide in the presence of potassium carbo... |
10785813 | Heat-shrinking spherical and columnar supramolecular dendrimers: their interconversion and dependence of their shape on molecular taper angle | Synthesis and modes of self-assembly are described for the tapered monodendritic molecules 3,4,5-nGi-X of generation i = 1, 2, 3 (see structures below) that contain multiple (CH2)nH alkyl chains on their periphery (n = 12, 14, 16) and a polar group X at the apex (X = COOH, COONa, COOCs, CO(OCH2CH2)3OH). These monodendr... |
10785803 | Host-guest interactions at self-assembled monolayers of cyclodextrins on gold | We have developed synthesis routes for the introduction of short and long dialkylsulfides onto the primary side of alpha-, beta-, and gamma-cyclodextrins. Monolayers of these cyclodextrin adsorbates were characterized by electrochemistry, wettability studies, X-ray photoelectron spectroscopy (XPS), time-of-flight secon... |
10783884 | Self-assembly of nanoparticles into structured spherical and network aggregates | Multi-scale ordering of materials is central for the application of molecular systems in macroscopic devices. Self-assembly based on selective control of non-covalent interactions provides a powerful tool for the creation of structured systems at a molecular level, and application of this methodology to macromolecular ... |
10774029 | Computational studies of inclusion phenomena and synthesis of a novel and selective molecular receptor for 1,4-disubstituted benzenes and 4,4'-disubstituted biphenyls | A new tetracationic molecular receptor has been synthesized and studied by semiempirical molecular orbital theory. This novel macrocycle, 1(4+), derived from pentacyclo[5.0.0.0.(2,6)0.(3,10)0(5,9)]undecane-8,11-dione (PCU-8,11-dione), structurally resembles cyclobis(paraquat-p-phenylene), 2(4+), in which a xylyl group ... |
10774018 | Regioselective chlorocarbonylation of polybenzyl cores and functionalization using dendritic and organometallic nucleophiles | Regiospecific chlorocarbonylation of the polybenzyl cores PhCH2CH2Ph, C6(CH2CH2Ph)6, 7, and CH(CH2Ph)24-1,2,4,5-C6H2, 8, in the para position of the benzyl groups gives the chlorocarbonyl derivatives 2, 9, and 10, respectively, in good yields. The octachlorocarbonyl derivative 10 reacts with Newkome's aminotripod NH2C(... |
10774013 | The electrochemically-driven decomplexation/recomplexation of inclusion adducts of ferrocene derivatives with an electron-accepting receptor | The tetracationic cyclophane, cyclobis(paraquat-4,4'-biphenylene), binds 1,1'-disubstituted ferrocene-based polyethers as a result of (i) [pi...pi] stacking between the pi-electron-deficient bipyridinium units and the pi-electron-rich cyclopentadienyl rings and (ii) [C-H...O] hydrogen bonds between the alpha-bipyridini... |
10774012 | Molecular shuttles by the protecting group approach | Two new [2]rotaxane-based molecular shuttles, in which a mechanically bound dibenzo[24]crown-8 (DB24C8) macroring shunts back and forth between two dialkylammonium recognition sites situated on a chemical dumbbell, have been constructed by a novel synthetic strategy that relies upon the use of the tert-butoxycarbonyl (... |
10774011 | Switching of pseudorotaxanes and catenanes incorporating a tetrathiafulvalene unit by redox and chemical inputs | An acyclic polyether 1a, incorporating a central tetrathiafulvalene (TTF) electron donor unit and two 4-tert-butylphenoxy groups at its termini, has been synthesized. Two macrocyclic polyethers containing two different electron donors, namely a TTF unit with, in one case, a 1,4-dioxybenzene ring (2a), and, in the other... |
10768185 | "Masterpiece" copolymer sequences by targeted equilibrium-shifting | We describe an equilibrium model to determine whether a random population of dynamic copolymer sequences could be driven by molecular recognition to a subset of sequences that tightly bind a specific ligand. The model predicts that the population's mean binding constant can be shifted, but because of competitive bindin... |
10767010 | Integration of Layered Redox Proteins and Conductive Supports for Bioelectronic Applications. | Integration of redox enzymes with an electrode support and formation of an electrical contact between the biocatalysts and the electrode is the fundamental subject of bioelectronics and optobioelectronics. This review addresses the recent advances and the scientific progress in electrically contacted, layered enzyme el... |
10727342 | The Influence of Alkali Metal Ions on Homogeneous Nucleation of Al(OH)(3) Crystals from Supersaturated Caustic Aluminate Solutions. | Homogeneous nucleation of Al(OH)(3) crystals from synthetic, optically clear, caustic aluminate solutions and the influence of alkali metal ion (Na(+) versus K(+)) have been investigated under isothermal, batch crystallization conditions. The nucleation kinetics showed a seventh-order dependence upon Al(III) relative s... |
12526469 | Interactions between divalent metal ions and an octacoordinate macrocyclic ligand. | A dinucleating hexaazadiphenol macrocyclic ligand, 15,31-dimethyl-3,11,19,27,33,35-hexaazapentacyclo[27.3.1.1.(5,9)1.(13,17)1. (21,25)]hexatriaconta-5,7,9(33),13,15,17(34),21,23,25(35),29,31,1(36)- dodecaene-34,36-diol (H2L), forms a number of protonated, neutral, and/or hydroxo mononuclear, homodinuclear, and heterodi... |
12526464 | Controlled molecular motions in copper-complexed rotaxanes: an XAS study. | The environment of the central metal of a molecular machine-like copper rotaxane was observed by XAS experiments. The wheel of the rotaxane is a hetero-bischelating macrocycle containing both bidentate (phenanthroline) and terdentate (terpyridine) moieties. The axle of the assembly contains only a bidentate moiety. App... |
12526458 | Cis-influence of hydroporphyrin macrocycles on axial ligation equilibria and alkyl exchange reactions of alkylcobalt(III) porphyrin complexes. | Stability constants are reported for the coordination of pyridine and substituted pyridines to the alkylcobalt(III) complexes of octaethylporphyrin (OEP), t-octaethylchlorin (OEC), and ttt-octaethylisobacteriochlorin (OEiBC) in toluene solution. The stability constants correlate with the base strength of the nitrogenou... |
12526446 | Stepwise assembly of unsymmetrical supramolecular arrays containing porphyrins and coordination compounds. | The stepwise coordination of meso-4'-pyridyl/phenyl porphyrins (4'-PyPs) to different metal centers proved to be an efficient synthetic approach leading to unsymmetrical arrays containing porphyrins and coordination compounds. The first step of this process, treatment of 4'-PyPs with a less than stoichiometric amount o... |
12526443 | alpha- and beta-cyclodextrin rotaxanes of mu-bis(4-pyridyl)bis[pentacyanoferrate(II)] complexes. | The kinetics and mechanism of the self-assemblies of alpha- and beta-cyclodextrin (CD) [2]rotaxanes, [(NC)5Fe-[pyRpy.CD]Fe(CN)5]6-, containing pentacyanoferrate(II)-stoppered 4,4'-bis(pyridyl) threads pyRpy (R = -CH = CH-, -N=N-, -CH=N-N=CH-, and -C(CH3)=N-N=C(CH3)-) have been investigated in aqueous solution by using ... |
12526438 | Binding of phosphate with a simple hexaaza polyammonium macrocycle. | A mixture of dihydrogen phosphate and phosphoric acid has been crystallized with a hexaprotonated 26-membered polyammonium macrocycle, 1,4,7,14,17,20-hexaazacyclohexacosane, as the counterion. The complex crystallizes in the monoclinic space group P2(1)/c with unit cell parameters of a = 10.006(2) A, b = 12.525(1) A, c... |
12212214 | [Comparative study of pulmonary magnetic resonance angiography (MRA)]. | Imaging was performed using a 1.0 Tesla superconducting MR system with a body coil. Two-dimensional(2D) turbo FLASH sequence and/or three-dimensional(3D) FISP sequence were carried out in 46 volunteers with 113 pulmonary MRA. The total MRAs were divided into 4 groups and analysed. The results showed: After Gd-DTPA was ... |
11720931 | The SGML standardization framework and the introduction of XML. | Extensible Markup Language (XML) is on its way to becoming a global standard for the representation, exchange, and presentation of information on the World Wide Web (WWW). More than that, XML is creating a standardization framework, in terms of an open network of meta-standards and mediators that allows for the definit... |
10749667 | Expression and characterization of a recombinant cysteine proteinase of Leishmania mexicana. | A major cysteine proteinase (CPB) of Leishmania mexicana, that is predominantly expressed in the form of the parasite that causes disease in mammals, has been overexpressed in Escherichia coli and purified from inclusion bodies to apparent homogeneity. The CPB enzyme, CPB2.8, was expressed as an inactive pro-form lacki... |
10749683 | Conserved residue lysine165 is essential for the ability of O6-alkylguanine-DNA alkyltransferase to react with O6-benzylguanine. | The role of lysine(165) in the activity of the DNA repair protein, O(6)-alkylguanine-DNA alkyltransferase (AGT), and the ability of AGT to react with the pseudosubstrate inhibitor, O(6)-benzylguanine (BG), was investigated by changing this lysine to all other 19 possibilities. All of these mutants (except for K165T, wh... |
11192737 | [Factors influencing liberation of drug from semisolid dosage forms]. | Liberation of salicylic acid--as a model active agent--was investigated from white petrolatum, creams w/o and o/w types and hydrogels. Active agent was applied in suspended, dissolved forms, in inclusion complexes and solubilized state. The process of liberation was studied by a continuous through-flow method, with Han... |
10994518 | Diffusion of water molecules in crystalline beta-cyclodextrin hydrates. | To understand the rapid diffusion mechanism of water molecules in the crystal lattice of hydrated beta-cyclodextrin (beta-CD), molecular dynamics (MD) simulations of crystalline beta-CD were performed at five different relative humidities corresponding to hydration states ranging from beta-CD-9.4H2O to beta-CD-12.3H2O,... |
10994514 | Single-coordinate-driving method for molecular docking: application to modeling of guest inclusion in cyclodextrin. | An extension of the computer program CICADA has been developed that allows us to use the single-coordinate-driving (SCD) method for flexible molecular docking. The docking procedure is composed of three independent space rotations, three independent translations, and the torsions selected by the user. One of the coordi... |
10966159 | Interactions between DNA and benzo- and tetrahydrobenzofurocoumarins: thermodynamic and molecular modeling studies. | The non-covalent interaction of a series of new water-soluble benzo- and tetrahydrobenzofurocoumarins with salmon testes DNA has been studied using flow linear dichroism, circular dichroism, contact fluorescence energy transfer and ethidium bromide displacement assay. The new derivatives are characterised by having an ... |
10858699 | Cholesterol crystallization in gall-bladder bile of pigs given cholesterol-beta-cyclodextrin-enriched diets with either casein or soyabean concentrate as protein sources. | Cholesterol precipitation from supersaturated bile is the earliest and determinant step in the formation of cholesterol gallstones, which is thought to be diet-dependent. Bile composition, appearance and growth of cholesterol crystals were studied in fresh gall-bladder biles from pigs adapted to four different protein-... |
10858032 | Esterification of polyunsaturated fatty acids by various forms of immobilized lipase from Rhizomucor miehei. | Ethyl esterification specificity of a lipase from Rhizomucor miehei for polyunsaturated fatty acids (PUFA) was compared at 1 and 100 mM to study molecular recognition of PUFA. The chemical shift of methylene adjacent to carboxyl groups in the nuclear magnetic resonance spectrum of docosahexaenoic acid (DHA) in ethanol ... |
10845800 | Chiral separation of homocysteine by derivatization with 4-aminosulfonyl-7-fluoro-2,1,3-benzoxadiazole followed by capillary electrophoresis using gamma-cyclodextrin. | Homocysteine was derivatized with 4-aminosulfonyl-7-fluoro-2,1,3-benzoxadiazole (ABD-F) to form an inclusion complex with cyclodextrin and to facilitate UV detection. ABD-homocysteine showed interaction with beta- and gamma-cyclodextrin in capillary electrophoresis at pH 2.25 as indicated by the decreased migration tim... |
10845694 | Influence of cyclodextrin complexation on the in vitro permeation and skin metabolism of dexamethasone. | The influence of complexation of a model drug, dexamethasone acetate (DMA), with beta-cyclodextrin (beta-CyD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CyD) on the in vitro permeation through hairless mouse skin and on skin metabolism have been investigated. Complexation with CyDs increased the amount of DMA permeat... |
10839166 | Separation of brompheniramine enantiomers by capillary electrophoresis and study of chiral recognition mechanisms of cyclodextrins using NMR-spectroscopy, UV spectrometry, electrospray ionization mass spectrometry and X-ray crystallography. | Opposite migration order was observed for the enantiomers of brompheniramine [N-[3-(4-bromphenyl)-3-(2-pyridyl)propyl]-N,N-dimethylamine] (BrPh) in capillary electrophoresis (CE) when native beta-cyclodextrin (beta-CD) and heptakis(2,3,6-tri-O-methyl)-beta-CD (TM-beta-CD) were used as chiral selectors. NMR spectrometry... |
10839165 | Mechanistic study of opposite migration order of dimethindene enantiomers in capillary electrophoresis in the presence of native beta-cyclodextrin and heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin. | The possible mechanisms of the opposite affinity pattern of the enantiomers of dimethindene [(R,S)-N,N-dimethyl-3[1(2-pyridyl)ethyl]indene-2-ethylamine] (DIM) towards native beta-cyclodextrin (beta-CD) and heptakis(2,3,6-tri-O-methyl-)-beta-CD (TM-beta-CD) were studied using capillary electrophoresis (CE), NMR spectrom... |
10839162 | Optimization of the cyclodextrin-assisted capillary electrophoresis separation of the enantiomers of phenoxyacid herbicides. | An ethylcarbonate derivative of beta-cyclodextrin (beta-CD) with three substituents per molecule, hydroxypropyl-beta-CD and native alpha-CD have been tested as resolving agents in the capillary zone electrophoresis (CZE) separation of the four enantiomers of the herbicides mecoprop and dichlorprop. The performances of ... |
10839160 | Fast chiral separations using sulfated beta-cyclodextrin and short-end injection in capillary electrophoresis. | The general applicability of sulfated beta-cyclodextrin as chiral selector and short-end injection in capillary electrophoresis (CE) as a powerful screening tool for fast and efficient chiral separation of Ormeloxifene enantiomers and racemic Ormeloxifene analogues is demonstrated. Using the short-end injection procedu... |
10839159 | Chiral capillary electrophoretic analysis of the enantiomeric purity of a pharmaceutical compound using sulfated beta-cyclodextrin. | A practical chiral capillary electrophoresis method using randomly sulfated beta-cyclodextrin was developed for the quantitative determination of the chiral purity of a pharmaceutical compound. A systematic method development approach was conducted by modifying selected parameters such as the concentration of the chira... |
10839158 | Enantioseparation of 3,4-dihydroxyphenylalanine and 2-hydrazino-2-methyl-3-(3,4-dihydroxyphenyl)propanoic acid by capillary electrophoresis using cyclodextrins. | The enantiomeric separations of 3,4-dihydroxyphenylalanine (dopa) and 2-hydrazino-2-methyl-3-(3,4-dihydroxyphenyl)propanoic acid (carbidopa) by capillary electrophoresis were studied using several native, neutral and anionic cyclodextrins as chiral additives and uncoated fused-silica capillaries. The effect of the type... |
10839157 | Direct chiral resolution of lactic acid in food products by capillary electrophoresis. | Chiral resolution of native DL-lactic acid was performed by capillary electrophoresis using 2-hydroxypropyl-beta-cyclodextrin as a chiral selector. Various factors affecting chiral resolution, migration time, and peak area of lactic acid were studied. The running conditions for optimum separation of lactic acid were fo... |
10839156 | Enhancement of chiral recognition by formation of a sandwiched complex in capillary electrophoresis. | For chiral primary amino compounds not separable by cyclodextrins alone, chiral recognition was successfully achieved by the formation of a sandwiched complex of the non-chiral 18-crown-6, the chiral amine and cyclodextrin (CD) [18-crown-6+amino compound+CD]. The separation of 1-methyl-3-phenylpropylamine and 1,2,3,4-t... |
10839152 | Separation of enantiomers by capillary electrophoresis-mass spectrometry employing a partial filling technique with a chiral crown ether. | Enantiomer separations were performed by capillary electrophoresis-mass spectrometry (CE-MS) with (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid (18C6H4) as a chiral selector. In order to prevent the introduction of the nonvolatile chiral, selector, 18C6H4, into the nozzle of the CE-MS interface and/or the orifice pla... |
10839151 | Enantiomeric separation by capillary electrophoresis with an electroosmotic flow-controlled capillary. | Perfect control of electroosmotic flow (EOF) was achieved by dovetailing successive multiple ionic-polymer layer (SMIL) coated capillaries. The direction and magnitude of the EOF was perfectly controllable over the pH range 2-13. Zone diffusion was not observed, even if the inner wall of the dovetailed capillary was di... |
10839147 | Enantiomer separation of chiral pharmaceuticals by capillary electrochromatography. | Enantiomer separation of chiral pharmaceuticals by capillary electrochromatography (CEC) is achieved with open-tubular capillaries (o-CEC), with packed capillaries (p-CEC) or with monolithic capillaries. In o-CEC, capillaries are coated with a thin film containing cyclodextrin derivatives, cellulose, proteins, poly-ter... |
10839144 | Enantiomeric separations by use of polymeric surfactant electrokinetic chromatography. | This review surveys the enantiomeric separation of drugs by electrokinetic chromatography using polymeric chiral surfactant pseudostationary phases. These phases have recently been shown to provide better mass transfer and increased rigidity and stability than regular micelles in micellar capillary electrophoresis. Cha... |
10839143 | Enantiomer separation of drugs by micellar electrokinetic chromatography using chiral surfactants. | A review surveying enantiomer separations by micellar electrokinetic chromatography (MEKC) using chiral surfactants is described. MEKC is one of the most popular techniques in capillary electrophoresis, where neutral compounds can be analyzed as well as charged ones, and the use of chiral micelles enable one to achieve... |
10839142 | Separation of drug enantiomers by capillary electrophoresis in the presence of neutral cyclodextrins. | This is a selected review, highlighting our results obtained in an extended screening program ("The German-Chinese Drug Screening Program"), with a focus on a set of original data obtained with heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin (TM-beta-CD) as the chiral solvating agent (CSA). The enantioseparation of 86 d... |
10839141 | Enantiomeric separations of drugs using mixtures of charged and neutral cyclodextrins. | An overview on the use of mixtures of neutral and charged cyclodextrins as chiral additives for the enantioseparation of drugs by capillary electrophoresis is presented. These so called dual cyclodextrin systems can often provide unique selectivities. A brief theoretical background illustrating the influence of the chi... |
10839140 | Enantioselective determination by capillary electrophoresis with cyclodextrins as chiral selectors. | This review surveys the separation of enantiomers by capillary electrophoresis using cyclodextrins as chiral selector. Cyclodextrins or their derivatives have been widely employed for the direct chiral resolution of a wide number of enantiomers, mainly of pharmaceutical interest, selected examples are reported in the t... |
10839139 | Chiral separation of amino acids and peptides by capillary electrophoresis. | Chiral separation of amino acids and peptides by capillary electrophoresis (CE) is reviewed regarding the separation principles of different approaches, advantages and limitations, chiral recognition mechanisms and applications. The direct approach details various chiral selectors with an emphasis on cyclodextrins and ... |
10832088 | An alternative approach to the preparation of (188)Re radiopharmaceuticals from generator-produced [(188)ReO(4)](-): efficient synthesis of (188)Re(V)-meso-2,3-dimercaptosuccinic acid. | A new efficient approach for the preparation of (188)Re radiopharmaceuticals starting from [(188)ReO(4)](-), produced at a carrier-free level through the (188)W/(188)Re generator system, is described. The reaction procedure was based on the combined action of different reagents and has been applied in detail to the pre... |
10831091 | MALDI-TOF MS analysis of a library of polymerizable cyclodextrin derivatives. | Polymerizable cyclodextrin derivatives (PCDs) have been proposed as candidates for use in dental therapeutics (Bowen, 1996; Bowen and Reed, 1997). Here, PCD "libraries" were synthesized by quasi-random reactions of 6 moles of methacrylic anhydride plus 6 moles of cyclic glutaric anhydride per mole of beta-cyclodextrin ... |
10830877 | Effect of low temperature on soybean peroxidase: spectroscopic characterization of the quantum-mechanically admixed spin state. | A spectroscopic study of soybean peroxidase (SBP) has been carried out using electronic absorption, resonance Raman (RR) and electron paramagnetic resonance (EPR) spectroscopy in order to determine the effects of temperature on the heme spin state. Upon lowering the temperature a transition from high spin to low spin i... |
10830484 | Effects of branched cyclodextrins on the solubility and stability of terpenes. | In order to investigate the application potential of branched CDs, the solubilizing ability and the stabilizing ability of G2-betaCD and GUG-betaCD were investigated by using twelve terpenes (d-limonene, myrcene, terpinolene, geraniol, l-menthol, nerol, alpha-terpineol, citral, d-citronellal, l-perillaldehyde, (R)-l-ca... |
10824593 | A sunscreen-tanning compromise: 3D visualization of the actions of titanium dioxide particles and dihydroxyacetone on human epiderm. | The self-tanning agent dihydroxyacetone (DHA) was applied to human skin samples, and its effect on light absorption was followed in time to study the DHA influence inside the different layers of skin. Application of DHA shows increased light absorption in the visible light region, as evidenced by skin tanning. The tann... |
10823464 | Cyclodextrin-catalyzed extraction of fluorescent sterols from monolayer membranes and small unilamellar vesicles. | This study examined the kinetics of sterol desorption from monolayer and small unilamellar vesicle membranes to 2-hydroxypropyl-beta-cyclodextrin. The sterols used include cholesterol, dehydroergosterol (ergosta-5,7,9,(11),22-tetraen-3beta-ol) and cholestatrienol (cholesta-5,7,9,(11)-trien-3beta-ol). Desorption rates o... |
10821402 | Chromatographic separation of chlorthalidone enantiomers using beta-cyclodextrins as chiral additives. | Different beta-cyclodextrins have been tested as chiral additives in the mobile phase for the chromatographic analysis of chlorthalidone enantiomers in a C18 LiChrospher (125 x 4 mm I.D.) column. The effect on enantioresolution of different parameters was studied: composition of the mobile phase (percentage of organic ... |
10819470 | Binding of nitrite and its reductive activation to nitric oxide at biomimetic copper centers. | The reactivity of nitrite towards the copper(II) and copper(I) centers of a series of complexes with tridentate nitrogen donor ligands has been investigated. The ligands are bis[(1-methylbenzimidazol-2-yl)methyl]amine (1-bb), bis[2-(1-methylbenzimidazol-2-yl)ethyl]amine (2-bb), and bis[2-(3,5-dimethyl-1-pyrazolyl)ethyl... |
10819468 | Formation of two types of low-spin heme in horseradish peroxidase isoenzyme A2 at low temperature. | Electronic absorption, resonance Raman and EPR spectra are reported for ferric horseradish peroxidase isoenzyme A2 at neutral and alkaline pH together with its imidazole complex at 12 K. The data are compared with those obtained at room temperature. At neutral pH, lowering the temperature induces conformational changes... |
10819163 | Structural studies on bioactive compounds. Part 29: palladium catalysed arylations and alkynylations of sterically hindered immunomodulatory 2-amino-5-halo-4,6-(disubstituted)pyrimidines. | The immunological agent bropirimine 5 is a tetra-substituted pyrimidine with anticancer and interferon-inducing properties. Synthetic routes to novel 5-aryl analogues of bropirimine have been developed and their potential molecular recognition properties analysed by molecular modelling methods. Sterically challenged 2-... |
10812935 | Improvement of water solubility and in vitro dissolution rate of gliclazide by complexation with beta-cyclodextrin. | Inclusion complexes of gliclazide with beta-cyclodextrin were prepared using different two methods: neutralization and recrysstalization. Host-guest interactions were studied in the solid state by X-ray diffractometry and infrared spectroscopy. The stability constant between gliclazide and beta-cyclodextrin was calcula... |
10809391 | Predominant torsional forms adopted by dipeptide conformers in solution: parameters for molecular recognition. | The present paper describes the predominant conformational forms adopted by dipeptides in aqueous solution. More than 50 dipeptides were subjected to conformational analysis using SYBYL Random Search. The resultant collections of conformers for individual dipeptides, for small groups with related side chain residues an... |
10804742 | Hypothetical pathophysiology of acute encephalopathy and encephalitis related to influenza virus infection and hypothermia therapy. | <h4>Background</h4>To establish a treatment strategy for acute encephalopathy and encephalitis associated with influenza virus infection, the pathophysiology of the disease was investigated through manifestations and laboratory findings of patients.<h4>Patients and methods</h4>A child with central nervous system (CNS) ... |
10804727 | Echocardiographic evaluation of the ductal morphology in patients with refractoriness to lipo-prostaglandin E1 therapy. | <h4>Background</h4>Lipo-prostaglandin (PG)E1 is effective at lower doses and has fewer side effects than PGE1-cyclodextrin (CD). Previous studies, however, have suggested that some patients show refractoriness to lipo-PGE1 in the course of treatment. The present paper examines: (i) whether such cases can be predicted b... |
10804567 | An efficient synthesis of cyclodextrin-based carbohydrate cluster compounds. | [formula: see text] The photoaddition of the thiol 2,3,4,6-tetra-O-acetyl-beta-D-1-thioglucopyranose to the allyl ether functions of per-2-allyl-, per-6-allyl-, and per-2,6-diallyl-beta-cyclodextrin derivatives provides a remarkably simple and efficient way for attaching glucopyranose units onto (1) the secondary face,... |
10804562 | Synthesis of carbamate-containing cyclodextrin analogues. | [formula: see text] The one-pot cyclooligomerization of a saccharide-derived p-nitrophenyl carbamate monomer was developed to generate a series of novel carbamate-containing cyclodextrin analogues. The "transcarbamoylation" occurs by initial base-induced activation to the isocyanate, followed by polycondensation/cycliz... |
10805530 | Time-resolved spectral observations of cadmium-enriched cadmium sulfide nanoparticles and the effects of DNA oligomer binding. | We measured the steady-state and time-resolved fluorescence spectral properties of cadmium-enriched nanoparticles (CdS-Cd2+). These particles displayed two emission maxima, at 460 and 580 nm. The emission spectra were independent of excitation wavelength. Surprisingly, the intensity decays were strongly dependent on th... |
10803899 | Cloning of the cyclodextrin glucanotransferase gene from alkalophilic Bacillus sp. A2-5a and analysis of the raw starch-binding domain. | The cyclodextrin glucanotransferase (CGTase) gene of alkalophilic Bacillus sp. A2-5a was cloned and expressed in Bacillus subtilis ANA-1 as a host. The DNA region included an open reading frame encoding a 704-amino-acid polypeptide with a typical raw starch-binding motif in its C-terminal region. The CGTase purified fr... |
10794926 | Investigation on the photostability of a tretinoin lotion and stabilization with additives. | Tretinoin, a drug that is used in topical preparations for the treatment of acne vulgaris, is known to be very susceptible to degradation under daylight. The objective of this work was to investigate the degradation of a tretinoin lotion placed in front of a xenon lamp. Analysis was performed with HPLC. The tretinoin l... |
10796025 | Reaction-diffusion waves of actin filament polymerization/depolymerization in Dictyostelium pseudopodium extension and cell locomotion. | Cell surface movements and the intracellular spatial patterns and dynamics of actin filament (F-actin) were investigated in living and formalin-fixed cells of Dictyostelium discoideum by confocal microscopy. Excitation waves of F-actin assembly developed and propagated several micrometers at up to 26 microm/min in cell... |
10792725 | A defined system for hybrid macrolide biosynthesis in Saccharopolyspora erythraea. | The biological activity of polyketide antibiotics is often strongly dependent on the presence and type of deoxysugar residues attached to the aglycone core. A system is described here, based on the erythromycin-producing strain of Saccharopolyspora erythraea, for detection of hybrid glycoside formation, and this system... |
10794412 | Crystal structure of adenosine kinase from Toxoplasma gondii at 1.8 A resolution. | Human infection with Toxoplasma gondii is an important cause of morbidity and mortality. Protozoan parasites such as T. gondii are incapable of de novo purine biosynthesis and must acquire purines from their host, so the purine salvage pathway offers a number of potential targets for antiparasitic chemotherapy. In T. g... |
10787041 | Neuroaxonal leukodystrophy associated with congenital cutis laxa: report of an autopsy case. | A male patient, who was born with congenital cutis laxa characterized by cutaneous laxity due to the degeneration of elastic fibers, presented with an arrest of mental and motor development at the age of 3 years. The progressive decline of the psychomotor abilities led to the patient's death at the age of 4 years and 9... |
10786864 | Incidence, site, and nature of injuries in amateur rugby league over three consecutive seasons. | <h4>Objectives</h4>To report the incidence, site, and nature of injuries in amateur rugby league over three consecutive seasons.<h4>Methods</h4>Six hundred players registered with an amateur rugby league organisation were studied over three consecutive seasons. All injuries sustained during the amateur rugby league mat... |
10786843 | Molecular recognition of amino acids by RNA aptamers: the evolution into an L-tyrosine binder of a dopamine-binding RNA motif. | We report the evolution of an RNA aptamer to change its binding specificity. RNA aptamers that bind the free amino acid tyrosine were in vitro selected from a degenerate pool derived from a previously selected dopamine aptamer. Three independent sequences bind tyrosine in solution, the winner of the selection binding w... |
10784430 | Absorption, distribution and excretion of galactosyl-beta-cyclodextrin and mannosyl-beta-cyclodextrin in rats. | Microanalytical methods were developed for measuring galactosyl-beta-cyclodextrin (Gal-betaCD) and mannosyl (Man)-betaCD in biological matrices of the rat by HPLC with pulsed amperometric detection. Then, using these methods, the absorption, distribution and excretion of intravenously and orally administered Gal-betaCD... |
10784359 | Dendrimer-assisted patch-clamp sizing of nuclear pores. | Macromolecular translocation (MMT) across the nuclear envelope (NE) occurs exclusively through the nuclear pore complex (NPC). Therefore, the diameter of the NPC aqueous/electrolytic channel (NPCC) is important for cellular structure and function. The NPCC diameter was previously determined to be approximately equal to... |
10784135 | Chiral separations of polar compounds by hydrophilic interaction chromatography with evaporative light scattering detection. | The chiral separations of drug substances and underivatized amino acids were demonstrated in this study through the use of hydrophilic interaction chromatography (HILIC). The polar character of the model compounds presented challenges for their analysis by traditional modes of chromatography, but through the employment... |
10780914 | Binding of norbinaltorphimine (norBNI) congeners to wild-type and mutant mu and kappa opioid receptors: molecular recognition loci for the pharmacophore and address components of kappa antagonists. | Molecular modifications of both the kappa opioid antagonist norbinaltorphimine (norBNI, 1) and the kappa receptor have provided evidence that the selectivity of this ligand is conferred through ionic interaction if its N17' protonated amine group (an "address") with a nonconserved acidic residue (Glu297) on the kappa r... |
10780964 | An improved in vitro bioassay for the study of 5-HT(4) receptors in the human isolated large intestinal circular muscle. | Recently, it was demonstrated that 5-HT induces relaxation of human colon circular muscle through activation of 5-HT(4) receptors and 5-HT(7) receptors. The aim of the current study was to develop a new in vitro bioassay of human colon that would facilitate the pharmacological analysis of 5-HT responses mediated solely... |
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