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11254337 | Structure Analysis of Montmorillonite Intercalated with Cetylpyridinium and Cetyltrimethylammonium: Molecular Simulations and XRD Analysis. | Molecular mechanics and molecular dynamics simulations combined with X-ray powder diffraction were used in structure investigation of montmorillonite intercalated with cetylpyridinium (CP) and cethyltrimethylammonium (CTA) cations. Molecular modeling revealed the interlayer structure and differences in intercalation be... |
11317287 | New Concepts in Tetrathiafulvalene Chemistry. | Tetrathiafulvalene (TTF) and its derivatives were originally prepared as strong electron-donor molecules for the development of electrically conducting materials. This Review emphasizes how TTF and its derivatives offer new and in some cases little-exploited possibilities at the molecular to the supramolecular levels, ... |
11301287 | Poly(amidoamine) (PAMAM) dendrimers: from biomimicry to drug delivery and biomedical applications. | Poly(amidoamine) (PAMAM) dendrimers are the first complete dendrimer family to be synthesized, characterized and commercialized. Based on this extensive activity, they are recognized as a unique new class of synthetic nanostructures. Dendrimers allow the precise control of size, shape and placement of functional groups... |
14993338 | Pharmacogenomics of cystic fibrosis. | Pharmacogenomics is becoming a frontline instrument of drug discovery, where the drug-dependent patterns of global gene expression are employed as biologically relevant end points. In the case of cystic fibrosis (CF), cells and tissues from CF patients provide the starting points of genomic analysis. The end points for... |
14538086 | Polymerized lipid vesicles as colorimetric biosensors for biotechnological applications. | Supramolecular chemical assemblies composed of polydiacetylene (PDA) exhibit rapid colorimetric transitions upon specific interactions with a variety of biological analytes in aqueous solutions. Among the analytes that give rise to the unique blue-red color changes are lipophilic enzymes, antibacterial peptides, ions, ... |
12947618 | [Spectral analysis on self-assembly ultrathin film of polyaminobenzonitrile]. | Poly(p-amino benzonitrile) (PABN) was synthesized by the method of plasma polymerization. With the self-assembly techniques, an ultrathin film of PABN and NaPSS (sodium polystyrene sulfonate) was successfully prepared. UV-Visible absorption spectra revealed that the film is very regular. This is a new method to prepare... |
11990574 | Fluorescence enhancement of coumarin-6-sulfonyl chloride amino acid derivatives in cyclodextrin media. | Coumarin-6-sulfonyl (6-CS) amino acid derivatives form inclusion complexes with a- and /-cyclodextrins (CD) in aqueous solution. The stoichiometry of the inclusion complex and the equilibrium constant were investigated. Using a fluorescence technique and alanine-beta-CD as a model, a 1:2 guest-host complex was establis... |
11990563 | Selective transport of silver ion through a supported liquid membrane using hexathia-18-crown-6 as carrier. | A facile supported liquid membrane (SLM) system for the selective and efficient transport of silver ion is introduced. The SLM used is a thin porous polyvinyldifluoride membrane impregnated with hexathia-18-crown-6 (HT18C6) dissolved in nitrophenyloctyl ether. HT18C6 acts as a specific carrier for the uphill transport ... |
11828453 | Nucleic acid supercoiling as a means for ionic switching of DNA--nanoparticle networks. | Oligomeric nanoparticle networks, generated by the self-assembly of bis-biotinylated double-stranded DNA fragments and streptavidin, have been studied by scanning force microscopy (SFM). SFM imaging revealed the presence within the networks of irregular thick DNA molecules, which were often associated with distinct, Y-... |
11795510 | On the true role of oxygen free radicals in the living state, aging, and degenerative disorders. | Oxyradicals are generally considered harmful byproducts of oxidative metabolism, causing molecular damage in living systems. They are implicated in various processes such as mutagenesis, aging, and series of pathological events. Although all this may be justified, evidence is accumulating that it is an oversimplified v... |
11563019 | Novel macrocycles derived from nucleosides. | A novel nucleoside-derived macrocycle formed from three thymidine 5'-carboxylic acid monomer units is described. |
11563046 | Ribose modified nucleosides and nucleotides as ligands for purine receptors. | Molecular modeling of receptors for adenosine and nucleotide (P2) receptors with docked ligand, based on mutagenesis, was carried out. Adenosine 3',5'-bisphosphate derivatives act as selective P2Y1 antagonists/partial agonists. The ribose moiety was replaced with carbocyclics, smaller and larger rings, conformationally... |
11471567 | Antigen-specific IgG antibodies in stage IV long-time survival breast cancer patients. | <h4>Background</h4>Profiling the immune responses in patients with cancer is expected to facilitate the design of diagnostic tests and therapeutic vaccines. Such studies usually require the parental antigens. We attempted to profile the immune responses in patients with breast cancer using a peptide phage display selec... |
11469496 | Tumor cell adhesion under hydrodynamic conditions of fluid flow. | Current evidence indicates that tumor cell adhesion to the microvasculature in host organs during formation of distant metastases is a complex process involving various types of cell adhesion molecules. Recent results have shown that stabilization of tumor cell adhesion to the microvascular vessel wall is a very import... |
11457110 | The secondary structure of a membrane-modifying peptide in a supramolecular assembly studied by PELDOR and CW-ESR spectroscopies. | The new technique of pulsed electron-electron double resonance in electron spin-echo (PELDOR) in combination with the CW-ESR method has been used to investigate the secondary structure of a double spin-labeled peptide (the [TOAC-1,8]-analogue of the peptaibol antibiotic trichogin GA IV) that is hidden into a tetrameric... |
11457054 | Modulating artificial membrane morphology: pH-induced chromatic transition and nanostructural transformation of a bolaamphiphilic conjugated polymer from blue helical ribbons to red nanofibers. | Design and characterization of helical ribbon assemblies of a bolaamphiphilic conjugated polymer and their color-coded transformation into nanofibers are described. An L-glutamic acid modified bolaamphiphilic diacetylene lipid was synthesized and self-assembled into right-handed helical ribbons with micron scale length... |
11457008 | Supramolecular chirogenesis in zinc porphyrins: mechanism, role of guest structure, and application for the absolute configuration determination. | The achiral syn folded (face-to-face conformation) host molecule of the ethane-bridged bis(zinc porphyrin) transforms into the corresponding chiral extended anti bis-ligated species in the presence of enantiopure amine guests. The mechanism of the supramolecular chirogenesis is based upon the screw formation in bis(zin... |
11451369 | Differential inhibition of recombinant bovine GH (rbGH) activity in vitro by in vivo enhancing monoclonal antibodies. | We have previously described the effects of complexing recombinant bovine growth hormone (rbGH) with the in vivo enhancing monoclonal antibodies (Mabs) OA11 and OA15 and the non-enhancing Mab OA14 on the subsequent activity of GH in different tissue culture models. We reported that all of these Mabs caused the inhibiti... |
11451037 | Effects of topical anandamide-transport inhibitors, AM404 and olvanil, on intraocular pressure in normotensive rabbits. | <h4>Purpose</h4>To evaluate the effects of topically applied anandamide transport inhibitors, AM404 and olvanil, on the intraocular pressure (IOP) of normotensive rabbits. To determine if the ocular hypotension induced by topical anandamide (AEA) can be potentiated by co-administered AM404.<h4>Methods</h4>Test compound... |
11398984 | Synthesis of branched cyclomaltooligosaccharide carboxylic acids (cyclodextrin carboxylic acids) by microbial oxidation. | Novel branched cyclomaltooligosaccharide carboxylic acid (cyclodextrin carboxylic acid) derivatives were synthesized by microbial oxidation using Pseudogluconobacter saccharoketogenes to oxidize five types of branched cyclodextrins, including maltosyl beta-cyclodextrin (maltosyl-beta-CyD). For each novel cyclodextrin c... |
11379966 | Methods for the determination of binding constants by capillary electrophoresis. | Apparent equilibrium constants for molecular association (e.g., association constants, binding constants, dissociation constants, partition coefficients) can be determined with a variety of different capillary electrophoresis (CE) approaches. In many cases, the investigated association behavior is between a smaller mol... |
11379965 | Enantioseparation of ofloxacin in urine by capillary electrokinetic chromatography using charged cyclodextrins as chiral selectors and assessment of enantioconversion. | A method was developed for the enantioseparation of ofloxacin, a member of the fluoroquinolones, using an anionic cyclodextrin-derivative with or without combination with a neutral cyclodextrin-derivative, as the chiral selector (s) in an electrokinetic chromatography system. The best results were obtained with 0.35 mM... |
11379964 | Simultaneous determination of disopyramide and mono-N-dealkyldisopyramide enantiomers in human plasma by capillary electrophoresis. | In this paper, a rapid method for the enantioselective analysis of the antiarrhythmic drug disopyramide and its main metabolite mono-N-dealkyldisopyramide in human plasma by capillary electrophoresis employing the cyclodextrin-modified electrokinetic chromatography mode is described. Sample clean-up was carried out by ... |
11379963 | Enantiomeric determination of praziquantel and its main metabolite trans-4-hydroxypraziquantel in human plasma by cyclodextrin-modified micellar electrokinetic chromatography. | A capillary electrophoresis method for the simultaneous quantitation of praziquantel and its main metabolite trans-4-hydroxypraziquantel enantiomers in human plasma was developed and validated using cyclodextrin-modified micellar electrokinetic chromatography. Sample clean-up involved a single-step liquid-liquid extrac... |
11379962 | Separation selectivity patterns in the capillary electrophoretic separation of anionic enantiomers by octakis-6-sulfato-gamma-cyclodextrin. | The capillary electrophoretic separation of anionic enantiomers with multiply-charged, single-isomer, anionic resolving agents was reexamined with the help of the charged resolving agent migration model. Three general model parameters were identified that influence the shape of the separation selectivity and enantiomer... |
11379961 | Separation of dipeptide and tripeptide enantiomers in capillary electrophoresis using carboxymethyl-beta-cyclodextrin and succinyl-beta-cyclodextrin: influence of the amino acid sequence, nature of the cyclodextrin and pH. | The separation of the LL and DD enantiomers of dipeptides and tripeptides using cyclodextrins (CDs) containing carboxyl groups was investigated with respect to the amino acid sequence of the peptides, the nature of the cyclodextrin and the buffer pH. Compared to succinyl-beta-cyclodextrin, carboxymethyl-beta-cyclodextr... |
11379959 | On-line coupling of partial filling-capillary zone electrophoresis with mass spectrometry for the separation of clenbuterol enantiomers. | The on-line coupling of capillary zone electrophoresis with mass spectrometry (CZE-MS) for the separation of enantiomers is hampered by the presence of nonvolatile chiral selectors such as cyclodextrins in the separation buffer. This problem can be overcome by use of the partial filling technique where only a part of t... |
11374594 | Spontaneous nucleophilic addition of hydroxide ions to the meso-position of high-valent antimony-oxo porphyrin complexes. | Bimolecular reactions of the antimony(V) porphyrin complexes SbO(tpp)OH, 1 and SbO(oep)OH, 2 with tetra-n-butylammonium hydroxide were investigated at 298 K in acetonitrile solution (tpp, dianion of 5,10,15,20-tetraphenylporphyrin and oep, dianion of 2,3,7,8,12,13,17,18-octaethylporphyrin). Spontaneous nucleophilic add... |
11374561 | The study of spectrosgraphic properties and molecular recognition of cali. | The absorption spectrum and fluorescence spectrum of calix[n]arenes are studied systematically. The self-association of calix[n]arenes is proposed and the self-association constant is also obtained. The recognition properties of calix[n]arenes are studied and the inclusion constant is calculated. |
11374576 | Inclusion complexes of Fe(III) tetrakis(4-sulfonatophenyl)porphyrin with cyclodextrins in aqueous solutions. | In aqueous solutions, inclusion complexation of Fe(III) tetrakis(4-sulfonatophenyl)porphyrin (FeTSPP) with alpha-cyclodextrin (alpha-CD), beta-CD, gamma-CD, and heptakis(2,3,6-tri-O-methyl)-beta-CD (TM-beta-CD) has been examined by means of absorption and induced circular dichroism spectroscopy. FeTSPP has been found t... |
11371069 | Determination of cyclodextrins and their derivatives by capillary electrophoresis with indirect UV and conductivity detection. | A fast and simple capillary electrophoretic method suitable for the determination of native alpha-, beta-, gamma-cyclodextrins, their randomly substituted tert-butyl derivatives (average degree of substitution 3.8-4.4), heptakis (2,6-di-O-methyl)- and heptakis (2,3,6-tri-O-methyl)-beta-cyclodextrin was developed. Napht... |
11361089 | Neuronal plasticity and regeneration in the olfactory system of mammals: morphological and functional recovery following olfactory bulb deafferentation. | The mammalian olfactory system has the unique property in the permanent turnover of the olfactory sensory neurons under normal conditions and following injury. This implies that the topographical map of the epithelium-to-bulb connections generated during ontogenesis has to be maintained despite neuron renewal in order ... |
11319891 | The theory and application of transition state pK(a) values: the reaction of papain with a series of trimethylene disulphide reactivity probes. | For many years methods to describe the structure of the transition state for a reaction have been sought. Most commonly these structures have been inferred from kinetic isotope effects. We report here for the first time the application of transition state pK(a) values to describe the relationship between molecular reco... |
11358873 | Glycobiology of sperm-egg interactions in deuterostomes. | The process of fertilization begins when sperm contact the outermost egg investment and ends with fusion of the two haploid pronuclei in the egg cytoplasm. Many steps in fertilization involve carbohydrate-based molecular recognition between sperm and egg. Although there is conservation of gamete recognition molecules w... |
11358248 | Trace level determination of enantiomeric monoterpenes in terrestrial plant emission and in the atmosphere using a beta-cyclodextrin capillary column coupled with thermal desorption and mass spectrometry. | For the first time, enrichment on solid sorbents followed by thermal desorption has been used for the determination of the enantiomeric signature of monoterpenes in the gaseous emission of terrestrial plants. A beta-cyclodextrin capillary column has been used for the separation of critical pairs. The temperature progra... |
11358255 | Potentiometric detection of organic acids in liquid chromatography using polymeric liquid membrane electrodes incorporating macrocyclic hexaamines. | Potentiometric detection employing coated-wire electrodes was applied to the determination of organic acids in liquid chromatography (LC). Poly(vinyl chloride)-based liquid membranes, incorporating lipophilic macrocyclic hexaamines as neutral ionophores were used as electrode coatings. The selectivity and sensitivity o... |
11358227 | Artifact-free matrix-assisted laser desorption ionization time-of-flight mass spectra of tert.-butyldimethylsilyl ether derivatives of cyclodextrins used for the synthesis of single-isomer, chiral resolving agents for capillary electrophoresis. | Artifact-free, high-resolution matrix-assisted laser desorption ionization (MALDI) time-of-flight mass spectra have been obtained for the labile, single-isomer, tert.-butyldimethylsilyl ether derivatives of alpha-, beta- and gamma-cyclodextrins by optimizing the MALDI sample preparation method. 2,5-Dihydroxybenzoic aci... |
11358226 | Study on the chiral recognition of the enantiomers of ephedrine derivatives with neutral and sulfated heptakis(2,3-O-diacetyl)-beta-cyclodextrins using capillary electrophoresis, UV, nuclear magnetic resonance spectroscopy and mass spectrometry. | The enantiomers of methylephedrine, pseudoephedrine and ephedrine showed a different migration behavior in capillary electrophoresis in the presence of beta-cyclodextrin (beta-CD), heptakis(2,3-O-diacetyl)-beta-cyclodextrin and heptakis(2,3-O-diacetyl-6-sulfato)-beta-cyclodextrin (HDAS). Utilizing UV, MS and NMR spectr... |
11358225 | Approaches to quantitative structure-enantioselectivity relationship modeling of chiral separations using capillary electrophoresis. | Quantitative structure-enantioselectivity relationships (QSERs) have been developed to describe the resolution of a series of chiral arylpropionic acids using capillary electrophoresis. Native beta-cyclodextrin and two derivatized forms are used as the chiral resolving agents. The QSER models are developed using the re... |
11358142 | Separation of divinyl ether fatty acid isomers by micellar electrokinetic chromatography. | A micellar electrokinetic chromatography (MEKC) method has been developed for the direct resolution of divinyl ether type of hydrophobic fatty acid isomers. The fatty acid isomers resolved include colneleic acid (CL), colnelenic acid (CLn), 14(Z)-etheroleic acid (14(Z)-EL), 14(Z)-etherolenic acid (14(Z)-Eln), 11(Z)-eth... |
11356485 | Chiral separations of 1,3,4-thia- and 1,3,4-selenadiazine derivatives by use of non-aqueous capillary electrophoresis. | Our aim was to establish suitable conditions for the chiral separation of 12 1,3,4-thia- and 1,3,4-selenadiazine derivatives; some of them were identified in screening tests as potential antituberculotics. To overcome possible problems with the water insolubility of most analytes, we profited by the advantages of non-a... |
11356483 | Separation of enantiomers by open capillary electrochromatography on polysiloxane-bonded permethyl-beta-cyclodextrin. | The separation of enantiomers by open capillary electrochromatography (o-CEC) using Chirasil-Dex as chiral stationary phase (CSP) is reviewed. In Chirasil-Dex, permethylated beta-cyclodextrin is linked via a single octamethylene spacer to polydimethylsiloxane. The CSP is coated and thermally immobilized onto the intern... |
11355423 | [Long-term outcome after multiple organ failure following severe trauma]. | <h4>Objective</h4>The aim of this follow-up study was to find out if severely injured patients with multiple organ failure (MOF) show any organotopic sequelae in the late course. Additionally the occupational rehabilitation result as well as the reasons for a poor occupational result were investigated.<h4>Methods</h4>A... |
11355821 | Determination of apparent association constants of steroid-cyclodextrin inclusion complexes using a modification of the Hummel-Dreyer method. | A modified Hummel-Dreyer method was used to calculate the apparent association constants of steroid-cyclodextrin inclusion complexes. An external calibration technique was employed, using the y-intercept from a plot of peak area versus concentration to correct for sample solvent effects. Mobile phase temperature and sa... |
11355806 | Uniformly sized molecularly imprinted polymer for (S)-naproxen retention and molecular recognition properties in aqueous mobile phase. | A uniformly sized molecularly imprinted polymer (MIP) for (S)-naproxen has been prepared by a multi-step swelling and polymerization method using 4-vinylpyridine (4-VPY) and ethylene glycol dimethacrylate (EDMA) as a functional monomer and cross-linker, respectively. We optimized the preparation method of the MIP by ch... |
11354461 | Predominant torsional forms adopted by oligopeptide conformers in solution: parameters for molecular recognition. | In this paper, we describe the predominant conformational forms adopted by tripeptides and higher oligopeptides in aqueous solution. About 50 tripeptides and almost 20 higher oligopeptides (4-6 residues) were subjected to conformational analysis using SYBYL Random Search. As with dipeptides (Grail BM, Payne JW. J. Pept... |
11354457 | Starch-hydrolyzing bacteria from Ethiopian soda lakes. | Alkaliphilic bacteria were isolated from soil and water samples obtained from Ethiopian soda lakes in the Rift Valley area--Lake Shala, Lake Abijata, and Lake Arenguadi. Starch-hydrolyzing isolates were selected on the basis of their activity on starch agar plate assay. Sixteen isolates were chosen, characterized, and ... |
11349914 | A self-threaded "molecular 8". | A new type of [1]rotaxanes containing two aliphatic bridges between axle and wheel is obtained in 39% yield in a one-step synthesis starting from a [2]rotaxane which contained one sulfonamide group each in both the wheel and the axle. Temperature controlled chemoselective substitution reactions first at these sulfonami... |
11349905 | Structural analysis of a metallosupramolecular polyelectrolyte-amphiphile complex at the air/water interface. | A detailed analysis of a metallosupramolecular coordination polyelectrolyte-amphiphile complex (PAC) at the air/water interface is presented based on Langmuir isotherm measurements, Brewster angle microscopy as well as X-ray reflectance and diffraction measurements. The PAC is prepared in solution by metal-ion coordina... |
11349819 | Very empirical treatment of solvation and entropy: a force field derived from log Po/w. | A non-covalent interaction force field model derived from the partition coefficient of 1-octanol/water solubility is described. This model, HINT for Hydropathic INTeractions, is shown to include, in very empirical and approximate terms, all components of biomolecular associations, including hydrogen bonding, Coulombic ... |
11348187 | Asymmetric induction in intramolecular meta photocycloaddition: cyclodextrin-mediated solid-phase photochemistry of various phenoxyalkenes. | [reaction: see text]. An approach to the asymmetric intramolecular meta photocycloaddition of phenoxyalkenes is described. The beta-cyclodextrin complexes of several phenoxyalkenes have been synthesized and irradiated in the solid phase. The effect of the CD-hosting on the regio- and enantioselectivity is discussed. Va... |
11345436 | Sequence-specific interaction between HIV-1 matrix protein and viral genomic RNA revealed by in vitro genetic selection. | The human immunodeficiency virus type-1 matrix protein (HIV-1 MA) is a multifunctional structural protein synthesized as part of the Pr55 gag polyprotein. We have used in vitro genetic selection to identify an RNA consensus sequence that specifically interacts with MA (Kd = 5 x 10(-7) M). This 13-nt MA binding consensu... |
11345431 | Generating new ligand-binding RNAs by affinity maturation and disintegration of allosteric ribozymes. | Allosteric ribozymes are engineered RNAs that operate as molecular switches whose rates of catalytic activity are modulated by the binding of specific effector molecules. New RNA molecular switches can be created by using "allosteric selection," a molecular engineering process that combines modular rational design and ... |
11345429 | Geometric nomenclature and classification of RNA base pairs. | Non-Watson-Crick base pairs mediate specific interactions responsible for RNA-RNA self-assembly and RNA-protein recognition. An unambiguous and descriptive nomenclature with well-defined and nonoverlapping parameters is needed to communicate concisely structural information about RNA base pairs. The definitions should ... |
11340974 | Enantioselective separation of epoxides by capillary electrophoresis employing sulfated beta-cyclodextrin as chiral selector. | A capillary electrophoresis method was developed for the enantioseparation of epoxide compounds. Sulfated beta-cyclodextrin was employed as a chiral selector. Phosphate-triethanolamine buffer showed a chiral separation effect when employing charged sulfated beta-cyclodextrin. The effect of pH, triethanolamine concentra... |
11338605 | Fluorescent cyclodextrin immobilized on a cellulose membrane as a chemosensor system for detecting molecules. | Dansyl glutamate-modified cyclodextrin (DnsGlu-beta-CD) was prepared as a fluorescent host, which is capable of being immobilized on a cellulose membrane (DnsGlu-beta-CD-membrane). The fluorescence intensity of DnsGlu-beta-CD decreased with increasing concentration of guest molecules, indicating that the host changes t... |
11338580 | Enantiomeric analysis of pharmaceutical compounds by ion/molecule reactions. | Protonated complexes involving cyclodextrin hosts and guest compounds that are pharmacologically important are produced in the gas phase and reacted with a gaseous amine. The guest is exchanged to produce a new protonated complex with the amine. The reaction is enantioselective and is used to develop a method for deter... |
11339278 | Utilization of the non-covalent fluorescent dye, NanoOrange, as a potential clinical diagnostic tool. Nanomolar human serum albumin quantitation. | The commercially available dye, NanoOrange, has been investigated as a potential tool for clinical diagnostics due to its low cost, ease of use, and ability to detect nanomolar concentrations of protein. Virtually non-fluorescent in dilute aqueous solutions, NanoOrange fluorescence is enhanced by at least an order of m... |
11336707 | Self-assembly of a viral molecular machine from purified protein and RNA constituents. | We present the assembly of the polymerase complex (procapsid) of a dsRNA virus from purified recombinant proteins. This molecular machine packages and replicates viral ssRNA genomic precursors in vitro. After addition of an external protein shell, these in vitro self-assembled viral core particles can penetrate the hos... |
11331307 | Rho-kinase--mediated contraction of isolated stress fibers. | It is widely accepted that actin filaments and the conventional double-headed myosin interact to generate force for many types of nonmuscle cell motility, and that this interaction occurs when the myosin regulatory light chain (MLC) is phosphorylated by MLC kinase (MLCK) together with calmodulin and Ca(2+). However, re... |
11331300 | Involvement of the lamin rod domain in heterotypic lamin interactions important for nuclear organization. | The nuclear lamina is a meshwork of intermediate-type filament proteins (lamins) that lines the inner nuclear membrane. The lamina is proposed to be an important determinant of nuclear structure, but there has been little direct testing of this idea. To investigate lamina functions, we have characterized a novel lamin ... |
11329709 | Understanding enantioselective processes: a laboratory rat model for alpha-hexachlorocyclohexane accumulation. | Since cyclodextrin gas chromatography columns became popular for chiral separations, many researchers have noticed high enantiomeric ratios [ER: (+)-enantiomer/(-)-enantiomer] for alpha-HCH in the brains of wildlife. This investigation used the laboratory rat as a model for these phenomena. Rats were either pretreated ... |
11330899 | A quantum-mechanical description of macrocyclic ring rotation in benzylic amide. | Catenanes can undergo rotation of one ring through the cavity of the other. Since macroscopic and molecular properties must clearly vary with the relative positions and orientations of the interlocked components, a complete understanding of the way that the rings rotate is of considerable importance. Here we show that ... |
11330891 | A polyrotaxane series containing alpha-cyclodextrin and naphthalene-modified alpha-cyclodextrin as a light-harvesting antenna system. | Supramolecular light-harvesting antenna systems were constructed by using polyrotaxanes, in which cyclodextrin (CD) rings of alpha-CD and naphthalene (energy donor)-appended alpha-CD are threaded by a poly(ethylene glycol) chain with anthracene (energy acceptor) units at both ends (5-8). The effects of the component ra... |
11330889 | Chemical synthesis of linear and cyclic unnatural oligosaccharides by iterative glycosidation of ketoses. | The development of an efficient method for the stereoselective synthesis of alpha-D-(2-->1)-linked ketoside oligomers is described. The method is based on an iterative protocol composed of two key steps: a) the coupling of a thiazolylketosyl phosphite donor with an hydroxymethylketoside acceptor; and b) the introductio... |
11328487 | Artificial ion channels formed by a synthetic cyclic peptide. | A new cyclic peptide 1 having an (LLLD)3 configuration pattern was designed that is capable of forming artificial transmembrane ion channels by self-assembly of planar peptide rings, with hydrophilic groups arrayed in the interior of the channel. Ion permeability in the presence of the synthetic peptide 1, cyclo[-Trp-D... |
11325589 | Molecular basis of Celmer's rules: role of the ketosynthase domain in epimerisation and demonstration that ketoreductase domains can have altered product specificity with unnatural substrates. | <h4>Background</h4>Polyketides are structurally diverse natural products with a range of medically useful activities. Non-aromatic bacterial polyketides are synthesised on modular polyketide synthase multienzymes (PKSs) in which each cycle of chain extension requires a different 'module' of enzymatic activities. Attemp... |
11325588 | Bivalent inhibition of human beta-tryptase. | <h4>Background</h4>Human beta-tryptase is a mast cell specific trypsin-like serine protease that is thought to play a key role in the pathogenesis of diverse allergic and inflammatory disorders like asthma and psoriasis. The recently resolved crystal structure revealed that the enzymatically active tetramer consists of... |
11327251 | Treatment of Raynaud's phenomenon with intravenous prostaglandin E1alpha-cyclodextrin improves endothelial cell injury in systemic sclerosis. | <h4>Objective</h4>To evaluate the efficacy and safety of prostaglandin (PG) E1alpha-cyclodextrin for Raynaud's phenomenon (RP) secondary to systemic sclerosis (SSc) and its effect on variables of immune activation and endothelial injury in SSc such as tumor necrosis factor-alpha (TNF-alpha), soluble interleukin 2 recep... |
11322778 | Substituted beta-cyclodextrins interact with PAMAM dendrimer-DNA complexes and modify transfection efficiency. | The efficiency of PAMAM dendrimer-mediated DNA transfer can be improved by the addition of substituted beta-cyclodextrins (beta-CDs) as formulation excipients. In vitro CAT expression increased approximately 200-fold when dendrimer/DNA/beta-CD formulations were applied on the surface of collagen membranes. The inclusio... |
11320245 | Controlling small guanine-nucleotide-exchange factor function through cytoplasmic RNA intramers. | ADP-ribosylation factor (ARF) GTPases and their regulatory proteins have been implicated in the control of diverse biological functions. Two main classes of positive regulatory elements for ARF have been discovered so far: the large Sec7/Gea and the small cytohesin/ARNO families, respectively. These proteins harbor gua... |
11320244 | Conversion of a maltose receptor into a zinc biosensor by computational design. | We have demonstrated that it is possible to radically change the specificity of maltose binding protein by converting it into a zinc sensor using a rational design approach. In this new molecular sensor, zinc binding is transduced into a readily detected fluorescence signal by use of an engineered conformational coupli... |
11321567 | The ostensible paradox of multidrug recognition. | The ability of multidrug-efflux transporters to recognize scores of dissimilar organic compounds has always been considered paradoxical because of its apparent contradiction to some of the basic dogmas of biochemistry. In order to understand, at least in principle, how a protein can recognize multiple compounds, we ana... |
11321316 | SoI--gel modification of pH electrode glass membranes for sensing anions and metal ions. | To obtain glass membrane electrodes selective for anions and metal ions, pH electrode glass membranes were modified by a sol-gel method using a quaternary ammonium salt and a bis(crown ether). A chloride ion-sensing glass membrane was designed, in which a pH electrode glass membrane was modified chemically by an alkoxy... |
11321314 | Detection of electrochemical enzymatic reactions by surface plasmon resonance measurement. | We describe the surface plasmon resonance (SPR) detection of an enzymatic turnover reaction and the measurement of glucose concentration using a multienzyme layer modified gold electrode. We constructed an osmium redox polymer mediated enzyme sensor on a gold thin-film electrode and monitored electrochemical reaction b... |
11321305 | Boronic acid fluorophore/beta-cyclodextrin complex sensors for selective sugar recognition in water. | A novel boronic acid fluorophore 1/beta-cyclodextrin (beta-CyD) complex sensor for sugar recognition in water has been designed. The probe 1 bearing pyrene moiety as a fluorescent signal transducer exhibits no fluorescence emission, due to its aggregation in water containing 2% DMSO; however, the addition of beta-CyD t... |
11318412 | Stereoselective determination of ofloxacin and its metabolites in human urine by capillary electrophoresis using laser-induced fluorescence detection. | A capillary electrophoresis method for the simultaneous separation and enantioseparation of the antibacterial drug ofloxacin and its metabolites desmethyl ofloxacin and ofloxacin N-oxide in human urine has been developed and validated. Enantioseparation was achieved by adding sulfobutyl beta-cyclodextrin to the running... |
11318069 | Correlation coefficients of solute relative retentions for pairs of modified cyclodextrins: evaluation of selectivity by differently responding gas chromatographic stationary phases. | Relative retention times versus the n-undecane for ten diverse probe solutes from volatile oils are scatterplotted between pairs of modified cyclodextrin (CD) phases. If the resulting line of best fit has a very high correlation coefficient (r), then the two CDs are behaving similarly and will not give different result... |
11312738 | Molecular tricorns: self-assembly of trinuclear palladium(II) complexes. | Cyclometalation of the ligand 1,3-bis(1-alkylbenzimidazol-2-yl)benzene (1) with palladium carboxylates leads to a trimeric complex [Pd(3)(ligand)(3)(carboxylate)(3)] (3). Studies in solution show that the trinuclear core is stable but that the carboxylates are labile, undergoing intra- and intermolecular exchange on an... |
11313599 | 1:2 Complexes of chloranilic acid with pyrazole and imidazole, and the acetonitrile solvate of a 1:1 complex with imidazole. | 2,5-Dichloro-3,6-dihydroxy-1,4-benzoquinone (chloranilic acid) forms X-H.Y (X, Y = N or O) and C-H.Cl hydrogen bonds with pyrazole and imidazole to afford bis(pyrazolium) dichloroanilate and bis(imidazolium) dichloroanilate, (I) and (II), both 2C(3)H(5)N(2)(+).C(6)Cl(2)O(4)(2-), and imidazolium chloroanilate acetonitri... |
11313594 | Aminopyrimidine-carboxyl(ate) interactions in trimethoprim maleate, an antifolate drug. | In the title cocrystal, trimethoprim maleate [2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidin-1-ium maleate], C(14)H(19)N(4)O(3)(+).C(4)H(3)O(4)(-), the trimethoprim molecule is protonated at N1. The carboxyl group of the maleate ion makes a specific double hydrogen bond of type N-H.O with the 2-amino group and the pro... |
11316148 | Nonsurgical management of ruptured pseudoaneurysm in patients with hepatobiliary pancreatic diseases. | <h4>Objective</h4>Rupture of a pseudoaneurysm is an unusual complication after surgical and interventional treatments in patients with hepatobiliary pancreatic diseases. However, it occurs abruptly and often results in a lethal outcome. The aim of this study was to retrospectively analyze our experiences of cases of ru... |
11309113 | Type IV secretion: intercellular transfer of macromolecules by systems ancestrally related to conjugation machines. | Bacterial conjugation systems are highly promiscuous macromolecular transfer systems that impact human health significantly. In clinical settings, conjugation is exceptionally problematic, leading to the rapid dissemination of antibiotic resistance genes and other virulence traits among bacterial populations. Recent wo... |
11309420 | Myopalladin, a novel 145-kilodalton sarcomeric protein with multiple roles in Z-disc and I-band protein assemblies. | We describe here a novel sarcomeric 145-kD protein, myopalladin, which tethers together the COOH-terminal Src homology 3 domains of nebulin and nebulette with the EF hand motifs of alpha-actinin in vertebrate Z-lines. Myopalladin's nebulin/nebulette and alpha-actinin-binding sites are contained in two distinct regions ... |
11309412 | An exclusively nuclear RNA-binding protein affects asymmetric localization of ASH1 mRNA and Ash1p in yeast. | The localization of ASH1 mRNA to the distal tip of budding yeast cells is essential for the proper regulation of mating type switching in Saccharomyces cerevisiae. A localization element that is predominantly in the 3'-untranslated region (UTR) can direct this mRNA to the bud. Using this element in the three-hybrid in ... |
11308366 | Structure, dynamics, and stability of beta-cyclodextrin inclusion complexes of aspartame and neotame. | Studies of the high-intensity sweetener aspartame show that its stability is significantly enhanced in the presence of beta-cyclodextrin (beta-CyD). At a 5:1 beta-CyD/aspartame molar ratio, the stability of aspartame is 42% greater in 4 mM phosphate buffer (pH 3.1) compared to solutions prepared without beta-CyD. Solut... |
11309244 | Effects of authentic and VLDL hydrolysis-derived fatty acids on vascular smooth muscle cell growth. | There are contradictory findings regarding the effects of free fatty acids on vascular smooth muscle cell (VSMC) growth. In the present study we investigated the effects of fatty acids released from hydrolysis of human VLDL triglycerides by lipoprotein lipase and of the fatty acids most abundant in the hydrolysed VLDL,... |
11308297 | Membrane lipid microdomains and the role of PKCtheta in T cell activation. | Productive T cell activation depends on the assembly of a highly ordered and compartmentalized immunological synapse or supramolecular activation complex (SMAC). Reorganization of the actin cytoskeleton and clustering of specialized membrane microdomains, or lipid rafts, occur early following TCR/CD3 and costimulatory ... |
11310679 | Synthesis of 2-substituted trifluoromethylquinolines for the evaluation of leishmanicidal activity. | The synthesis of 2-substituted-trifluoromethylquinolines from aniline, trifluoromethylanilines, 3-aminoquinoline and trifluoromethylquinaldines is reported. In vitro antileishmanial evaluation of 2-alkyl, 2-alkenyl and 2-epoxypropyl-trifluoromethylquinolines is presented. |
11306613 | Differential mechanisms of neuroprotection by 17 beta-estradiol in apoptotic versus necrotic neurodegeneration. | The major goal of this study was to compare mechanisms of the neuroprotective potential of 17 beta-estradiol in two models for oxidative stress-independent apoptotic neuronal cell death with that in necrotic neuronal cell death in primary neuronal cultures derived from rat hippocampus, septum, or cortex. Neuronal apopt... |
11304145 | Acid-base and spectroelectrochemical properties of doubly N-confused porphyrins. | The cis-doubly N-confused porphyrin, H2N2CP, containing two adjacent confused pyrrole rings has been investigated from the point of view of its acid-base and electrochemical behavior in dichloromethane. This novel porphyrin isomer can form two metal-carbon bonds in the central core, stabilizing metal ions in unusually ... |
11304195 | Total synthesis of a conformationally constrained didemnin B analog. | The total synthesis of a didemnin B analogue containing a conformationally constrained replacement for the isostatine moiety is reported. Synthetic highlights include an improved preparation of 2-hydroxy-3-cyclohexenecarboxylic acid and a new strategy for accessing the macrocycle. |
11304181 | Effect of progressive benzyl substitution on the conformations of aminocaproic acid-cyclized dipeptides. | The constraint of dipeptides into a beta-turn conformation can be accomplished by linking the two ends of a standard dipeptide with a linker derived from aminocaproic acid (Aca). To elucidate the possibility of using substituted Aca linkers in peptidomimetic design, a series of five macrocycles composed of a monobenzyl... |
11305602 | A moderate interaction of maltosyl-alpha-cyclodextrin with Caco-2 cells in comparison with the parent cyclodextrin. | The cytotoxicity of maltosyl-alpha-cyclodextrin (G2-alpha-CyD) and maltosyl-beta-cyclodextrin (G2-beta-CyD) toward Caco-2 cells was compared with that of natural alpha-cyclodextrin (alpha-CyD), beta-cyclodextrin (beta-CyD) and gamma-cyclodextrin (gamma-CyD). The degree of increase in cytotoxicity was dependent on the C... |
11303730 | Blood transfusion and the two-insult model of post-injury multiple organ failure. | Neutrophils (PMNs) have been implicated in the pathogenesis of multiple organ failure (MOF). The two-insult model of MOF is based on the fundamental concept that two sequential and independent insults that are individually innocuous against the host can cause overwhelming inflammation. The in vitro PMN priming/activati... |
11297934 | Polarizable force fields. | Standard force fields used in biomolecular computing describe electrostatic interactions in terms of fixed, usually atom-centered, charges. Real physical systems, however, polarize substantially when placed in a high-dielectric medium such as water--or even when a strongly charged system approaches a neutral body in th... |
11298323 | The clustered Fcgamma receptor II is recruited to Lyn-containing membrane domains and undergoes phosphorylation in a cholesterol-dependent manner. | Phosphorylation of clustered Fcgamma receptor II (FcgammaRII) by Src family tyrosine kinases is the earliest event in the receptor signaling cascade. However, the molecular mechanisms for the interaction between FcgammaRII and these kinases are not elucidated. To asses this problem we isolated high molecular weight com... |
11298765 | Influence of cyclodextrin ring substituents on folding-related aggregation of bovine carbonic anhydrase. | A common obstacle to proper renaturation of an unfolded protein is aggregation, an intermolecular side reaction of immense importance in biotechnology and in the pathogenesis of several neurodegenerative diseases. Cyclic sugars known as cyclodextrins have been used as protein-folding aids. The effect of cyclodextrin ch... |
11295225 | Modulation of drug release from hydrogels by using cyclodextrins: the case of nicardipine/beta-cyclodextrin system in crosslinked polyethylenglycol. | A simple approach is presented to modulate drug delivery from swellable systems by using complexants. The effect of complexants has been interpreted by means of simple mass balances on diffusing species and the involved relevant parameters have been individuated. The application of this strategy to the release of nicar... |
11296236 | The structural basis of acyl coenzyme A-dependent regulation of the transcription factor FadR. | FadR is an acyl-CoA-responsive transcription factor, regulating fatty acid biosynthetic and degradation genes in Escherichia coli. The apo-protein binds DNA as a homodimer, an interaction that is disrupted by binding of acyl-COA: The recently described structure of apo-FadR shows a DNA binding domain coupled to an acyl... |
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