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12212793 | Per-6-substituted beta-cyclodextrin libraries inhibit formation of beta-amyloid-peptide (A beta)-derived, soluble oligomers. | Alzheimer's disease is the most common cause of dementia in older individuals with compelling evidence favoring neuron dysfunction and death triggered by assembled forms of A beta(1-42). While large neurotoxic amyloid fibrils have been known for years, recent studies show that soluble protofibril and A beta(1-42)-deriv... |
12212740 | Studies on synthesis and infrared and fluorescence spectra of new europium and terbium complexes with an amide-based open-chain crown ether. | An amide-based open-chain crown ether ligand and its complexes with europium and terbium were synthesized. The complexes were characterized by elemental analysis, infrared spectra and conductivity. The europium and terbium ions were found to coordinate to the C=O oxygen atoms and pyridine nitrogen atoms. The fluorescen... |
12209631 | Lipid rafts as the signaling scaffold for NK cell activation: tyrosine phosphorylation and association of LAT with phosphatidylinositol 3-kinase and phospholipase C-gamma following CD2 stimulation. | Natural killer (NK) cells participate in both innate and adaptive immunity through the prompt secretion of cytokines and ability to lyse virally infected cells or tumor cells. Although it has been well understood that lipid rafts (rafts) and a raft-associated linker for activation of T cells (LAT) plays a central role ... |
12210202 | Chiral analysis of biogenic DL-amino acids derivatized by urethane - protected alpha-amino acid N-carboxyanhydride using capillary zone electrophoresis and micellar electrokinetic chromatography. | A new analytical method for enantioselective separation of DL-amino acids derivatized by N-fluorenylmethoxycarbonyl-L-alanyl N-carboxyanhydride (FMOC-L-Ala-NCA) using capillary electrophoresis was developed. Separation parameters, such as composition and pH of the background electrolyte, and concentration of gamma-cycl... |
12210195 | Application of capillary electrophoresis with field-amplified sample injection for the detection of new adrenoreceptor antagonist enantiomers in plasma in the low ng/mL concentration range. | Throughout the separation of chiral basic drugs by capillary electrophoresis (CE) with neutral hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as chiral selector, the sensitivity of detection has been improved by using field-amplified sample injection (FASI). In the present work, this on-line stacking method has been used... |
12210509 | Liquid chromatographic resolution of gemifloxacin mesylate on a chiral stationary phase derived from crown ether. | A new racemic fluoroquinolone antibacterial agent, gemifloxacin mesylate, has been successfully resolved on a chiral stationary phase (CSP) derived from (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid. Compared to the Crownpak CR(+) column, the CSP used in this study was more effective for the resolution of racemic gem... |
12204689 | Functional analysis of the lipoglycodepsipeptide antibiotic ramoplanin. | The peptide antibiotic ramoplanin is highly effective against several drug-resistant gram-positive bacteria, including vancomycin-resistant Enterococcus faecium (VRE) and methicillin-resistant Staphylococcus aureus (MRSA), two important opportunistic human pathogens. Ramoplanin inhibits bacterial peptidoglycan (PG) bio... |
12203307 | Fluorescence of dyes adsorbed on highly organized, nanostructured gold surfaces. | It is shown that fluorescent dyes can be adsorbed selectively on gold nanoparticles which are immobilized on a glass substrate and that the fluorescence originating from the adsorbed dyes exhibits significantly less quenching when compared to dyes adsorbed on bulk gold. Self-assembled monolayers of lissamine sulfide mo... |
12203295 | Weak hydrogen bonding as a basis for concentration-dependent guest selectivity by a cyclophane host. | Crystalline inclusion complexes between the cyclophane 1 and three isomers of picoline and lutidine were grown and their properties and structures were studied by X-ray analysis, thermal gravimetry (TG), and differential scanning calorimetry (DSC). In competition experiments, the cyclophane host, which by itself is onl... |
12203289 | Probing the stereointegrity of Tröger's base--a dynamic electrokinetic chromatographic study. | Under acidic conditions the enantiomers of Tröger's base 1 (2,8-dimethyl-6 H,12 H-5,11-methanodibenzo[b,f][1,5]diazozine) are subject to enantiomerization. During enantioselective dynamic electrokinetic chromatography using 10 mM hydroxypropyl-beta-cyclodextrin as the chiral mobile phase additive in 50 mM tris/phosphat... |
12203334 | Mass spectrometric characterization and gas-phase chemistry of self-assembling supramolecular squares and triangles. | A detailed mass spectrometric characterization of self-assembling polynuclear metal complexes is described. The complexes can only be ionized as intact species under a surprisingly narrow range of conditions by electrospray ionization. Comparison with the results from NMR experiments shows that several solution-phase f... |
12203332 | The anatomy of the energetics of molecular recognition by calorimetry: chiral discrimination of camphor by alpha-cyclodextrin. | The molecular recognition of both camphor enantiomers 2 with the chiral alpha-cyclodextrin (alpha-CD) 1 in water and D(2)O was examined by calorimetry. On the basis of statistically supported determinations the thermodynamics of 2:1 host-guest binding and chiral discrimination was evaluated. The energetic signature str... |
12203325 | Helical self-organization and hierarchical self-assembly of an oligoheterocyclic pyridine-pyridazine strand into extended supramolecular fibers. | The synthesis and characterization of an alternating pyridine-pyridazine strand comprising thirteen heterocycles are described. Spontaneous folding into a helical secondary structure is based on a general molecular self-organization process enforced by the conformational information encoded within the primary structure... |
12203318 | Templating and selection in the formation of macrocycles containing [[P(micro-NtBu)(2)](micro-NH)](n) frameworks: observation of halide ion coordination. | Amination of [ClP(micro-NtBu)](2) (1) using NH(3) in THF gives the cyclophospha(III)zane dimer [H(2)NP(micro-NtBu)](2) (2), in good yield. (31)P NMR spectroscopic studies of the reaction of 1 with 2 in THF/Et(3)N show that almost quantitative formation of the cyclic tetramer [[P(micro-NtBu)](2)(micro-NH)](4) (3) occurs... |
12203314 | Photoinduced formation of a cryptand from a coronand: an unexpected switch in cation binding affinity. | Aza-crown ethers 2 and 3 with anthracene-containing pendant arms have been synthesised and characterised. Both compounds bind Group 1 metal cations in solution, forming complexes of 1:1 stoichiometry. The properties of compound 2 and its complexes have been studied by a range of techniques, including NMR, UV and fluore... |
12203312 | Vine-twining polymerization: amylose twines around polyethers to form amylose-polyether inclusion complexes. | In this paper, we describe a new polymerization manner termed as "vine-twining polymerization" to produce amylose-polymer inclusion complexes. The polymerization was achieved by an enzymatic polymerization of alpha-D-glucose-1-phosphate monomer catalyzed by phosphorylase in the presence of polyTHF as a guest polymer. T... |
12203414 | Macromolecules containing bipyridine and terpyridine metal complexes: towards metallosupramolecular polymers. | The ability of a broad range of N-heterocycles to act as very effective and stable complexation agents for several transition metal ions, such as cobalt(II), copper(II), nickel(II), and ruthenium(II), has long been known in analytical chemistry. This behavior was later utilized in supramolecular chemistry for the const... |
12200837 | Liquid chromatographic determination of alcohols in food and beverages with indirect polarimetric detection using a beta-cyclodextrin mobile phase. | An indirect polarimetric detection method for the determination of alcohols has been proposed in liquid chromatography (LC). Optically active mobile-phase additives, such as beta-cyclodextrin (beta-CD), could be used to visualize optically inactive alcohols in reversed-phase LC. The visualization of alcohols is based o... |
12199604 | Elucidation of a polychlorinated bipyrrole structure using enantioselective GC. | A hexachloro congener (Q1-hex) of the natural heptachloro-1'-methyl-1,2'-bipyrrole Q1 was recently observed as a byproduct of the Q1 synthesis. NMR investigation confirmed that Q1-hex has a proton on a carbon in beta-position to a nitrogen. Three isomers are possible that fulfill this prerequisite; unfortunately, howev... |
12199562 | Integrated microfluidic system enabling (bio)chemical reactions with on-line MALDI-TOF mass spectrometry. | A continuous flow micro total analysis system (micro-TAS) consisting of an on-chip microfluidic device connected to a matrix assisted laser desorption ionization [MALDI] time-of-flight [TOF] mass spectrometer (MS) as an analytical screening system is presented. Reaction microchannels and inlet/outlet reservoirs were fa... |
12197000 | A new supramolecular system of racemic-bis-beta-naphthol, benzoquinone and aromatic hydrocarbon, which shows high molecular recognition ability. | Racemic-bis-beta-naphthol, benzoquinone and aromatic hydrocarbons formed a new three component supramolecular system as black crystals. X-ray analysis of the crystals shows that (+)- and (-)-bis-beta-naphthol and benzoquinone form a quinhydrone-type crystalline lattice with aromatic stacking and hydrogen bonding in whi... |
12196995 | Effective recognition of H2PO4- by a new series of dendrimers functionalized with ferrocenyl-urea termini. | A new series of dendrimers with poly(propylene imine) backbones and 4, 8, 16, or 32 peripheral ferrocenyl-urea groups were prepared and characterized; their voltammetric behavior in DMSO solution was very sensitive to the presence of hydrogenphosphate anions at submillimolar concentration levels. |
12196990 | Dendritic cavitands: preparation and electrochemical properties. | A new series of dendrimers containing a central cavitand core with four appended Fréchet-type dendrons, linked to the core through 4,4'-bipyridinium (viologen) subunits, have been synthesized, characterized and their electrochemical properties investigated using cyclic voltammetric measurements. |
12196973 | Monitoring the differential ordering of enantiomers included into cyclodextrins through deuterium NMR in lyotropic liquid crystals. | Deuterium NMR in an aqueous non-chiral liquid crystal allows the discrimination of enantiomers through their ordering inside beta-cyclodextrins. |
12196972 | Multi-temporal self-organizations in 1,3-O,O'-bis(dodecyl)calix[4]arene. | After heat erases the order in 1,3-O,O'-bis(dodecyl)calix[4]arene, it self-organizes the phenyl units into a rigid calix bowl first at T2 = 111 degrees C, followed by the formation of all-trans alkyl chains at T1 = 62 degrees C, which eventually yields a stable cone-shaped structure at room temperature. |
12196952 | Supramolecular acid/base catalysis via multiple hydrogen bonding interaction. | 2-Ureidoisocytosine bearing a phosphonium ion functionality self-assembles in an anti-parallel manner, to exhibit a cooperative acid/base catalysis for the ring-opening reaction of an epoxide. |
12196950 | Thia-calix[n]pyridines, synthesis and coordination to Cu(I,II) ions with both N and S donor atoms. | The novel thia-calix[n]pyridines (n = 3, 4, 6) coordinated to copper ions through nitrogen and sulfur atoms to give multinuclear complexes whose structures have been determined by X-ray crystallography and NMR spectra. |
12196943 | Formation of a tris-capsule and a tris-carceplex from a cyclic six-bowl assembly. | A macrocycle composed of six cavitands was assembled into a tris-capsule and a tris-carceplex, each of which encapsulates three guest molecules. |
12196390 | A heritable structural alteration of the yeast mitochondrion. | Prions have revived interest in hereditary change that is due to change in cellular structure. How pervasive is structural inheritance and what are its mechanisms? Described here is the initial characterization of [Leu(P)], a heritable structural change of the mitochondrion of Saccharomyces cerevisiae that often but no... |
12196129 | Cholesterol and Alzheimer's disease. | Accumulation of a 40-42-amino acid peptide, termed amyloid-beta peptide (A beta), is associated with Alzheimer's disease (AD), and identifying medicines that inhibit A beta could help patients with AD. Recent evidence suggests that a class of medicines that lower cholesterol by blocking the enzyme 3-hydroxy-3-methylglu... |
12196093 | Novartis Medal Lecture. Antibodies: a paradigm for the evolution of molecular recognition. | Novel proteins have been elaborated over evolutionary time by an iterative alternation of mutation and selection. In a similar way, the humoral immune system also uses an iterative alternation of mutation and selection to generate novel antibodies that display a high affinity for their cognate antigen -- but this is ac... |
12195950 | Biocatalytic precipitation induced by an affinity reaction on dendrimer-activated surfaces for the electrochemical signaling from immunosensors. | We have developed a strategy of signal generation for immunosensors that transduces biospecific affinity recognition reactions into electrochemical signals. The cyclic voltammetric method, tracking the precipitation of insoluble products onto the sensing surface and the subsequent decrement in the electrode area, was c... |
12194219 | Photodynamic properties of amphiphilic derivatives of aluminum tetrasulfophthalocyanine. | Photodynamic therapy (PDT) is a promising treatment modality that has recently been accepted in clinics as a curative or palliative therapy for cancer and other nonmalignant conditions. Phthalocyanines (Pc) are attractive photosensitizers for PDT because of their enhanced photophysical and photochemical properties. The... |
12193461 | Functional compartmentation of endothelial P2Y receptor signaling. | The presence of multiple receptors for disparate nucleotides on endothelial cells makes it unclear how the endothelium differentiates among these signals. We propose that endothelial P2Y receptors are organized into cholesterol-rich signaling domains, such as caveolae and respond to nucleotide agonists by mobilizing in... |
12191778 | Expression of PrP(C) as HIS-fusion form in a baculovirus system and conversion of expressed PrP-sen to PrP-res in a cell-free system. | Conversion of the PrP cellular form (PrP(C)) to the pathogenic form (PrP(Sc)) is the key step in the pathogenesis of transmissible spongiform encephalophathies. Although the mechanism of conformational conversion of PrP proteins remains uncertain, the cell-free conversion reaction and other in vitro PrP amplification t... |
12191475 | X-ray crystal structure and functional analysis of vaccinia virus K3L reveals molecular determinants for PKR subversion and substrate recognition. | The vaccinia virus protein K3L subverts the mammalian antiviral defense mechanism by inhibiting the RNA-dependent protein kinase PKR. K3L is a structural mimic of PKR's natural substrate, the translation initiation factor eIF2alpha. To further our understanding of K3L inhibitory function and PKR substrate recognition, ... |
12190321 | Influence of bulky substituents on histamine h(3) receptor agonist/antagonist properties. | Novel derivatives of 3-(1H-imidazol-4-yl)propanol were designed on the basis of lead compounds belonging to the carbamate or ether series possessing (partial) agonist properties on screening assays of the histamine H(3) receptor. One pair of enantiomers in the series of alpha-methyl-branched chiral carbamates was stere... |
12192145 | Capillary electrophoresis of anthraquinones from Cassia siamea. | The separation and determination of two anthraquinones, emodin and chrysophanol, and two bianthraquinones, cassiamin A and cassiamin B, were achieved by capillary electrophoresis (CE). The running electrolyte used in this method was 0.05 M hydroxypropyl-gamma-cyclodextrin in 0.1 M borate buffer (pH 9) containing 10% ac... |
12188672 | Supramolecular assembly at interfaces: formation of an extended two-dimensional coordinate covalent square grid network at the air-water interface. | Reaction of a Langmuir monolayer of an amphiphilic pentacyanoferrate(3+) complex with Ni(2+) ions from the subphase results in the formation of a two-dimensional iron-nickel cyanide-bridged network at the air-water interface. The network can be transferred to various supports to form monolayer or multilayer lamellar fi... |
12188670 | Nucleophilically assisted and cationic ring-opening polymerization of tin-bridged [1]ferrocenophanes. | To obtain mechanistic insight, detailed studies of the intriguing "spontaneous" ambient temperature ring-opening polymerization (ROP) of tin-bridged [1]ferrocenophanes Fe(eta-C(5)H(4))(2)SnR(2) 3a (R = t-Bu) and 3b (R = Mes) in solution have been performed. The investigations explored the influence of non-nucleophilic ... |
12188661 | Modulating ion channel properties of transmembrane peptide nanotubes through heteromeric supramolecular assemblies. | A selective heteromeric supramolecular assembly process is devised to create functional single channels of altered ion conductance, charge selectivity, and rectification. The hollow transmembrane tubular structure produced spontaneously from the self-assembly of cyclic-d,l-alpha-peptides in lipid bilayers is modified b... |
12188658 | Long-range self-assembly of a polyunsaturated linear organosilane at the n-tetradecane/Au(111) interface studied by STM. | We report on the formation of self-assembled monolayers of 13-(trimethylsilyl)-1-tridecene-6,12-diyne [C13H17-Si(CH3)3], an organosilane derivative with a linear polyunsaturated chain, on Au(111) substrates. Molecular resolution STM images recorded at the liquid-solid interface between gold and tetradecane reveal a lon... |
12188654 | Supramolecular isomerism in coordination compounds: nanoscale molecular hexagons and chains. | A nanoscale supramolecular hexagon, 1, and its supramolecular isomeric chain structure, 2, have been prepared from self-assembly of 5-NO2-bdc and Cu(II) cations. The hexagon is neutral and soluble and has outer and inner diameters of 3.1 and 0.8 nm, respectively. |
12186836 | Blockade of HIV-1 infection of New World monkey cells occurs primarily at the stage of virus entry. | HIV-1 naturally infects chimpanzees and humans, but does not infect Old World monkeys because of replication blocks that occur after virus entry into the cell. To understand the species-specific restrictions operating on HIV-1 infection, the ability of HIV-1 to infect the cells of New World monkeys was examined. Primar... |
12186559 | Position-dependent hydrophobicity of the antimicrobial magainin peptide affects the mode of peptide-lipid interactions and selective toxicity. | Cationic antimicrobial peptides are promising candidates as novel antibiotics of clinical usefulness. Magainin 2, a representative antimicrobial peptide isolated from the skin of the African clawed frog Xenopus leavis, electrostatically recognizes anionic lipids that are abundant in bacterial membranes, forming a pepti... |
12185216 | Oral candidiasis. | Oral candidiasis is a common opportunistic infection of the oral cavity caused by an overgrowth of Candida species, the commonest being Candida albicans. The incidence varies depending on age and certain predisposing factors. There are three broad groupings consisting of acute candidiasis, chronic candidiasis, and angu... |
12184780 | Flexible square supramolecular rings with hydrogen-bonded bushing in solid-state oxalurate complexes: versatility of the oxalurate ligand in covalent and noncovalent binding. | Isotypic pseudooctahedral complexes of Co, Ni, and Cu with two chelating oxalurate ligands and two water molecules, trans-[M(oxalurate)(2)(H(2)O)(2)], have been synthesized and isolated by a novel progressive crystallization technique. Diffraction analyses reveal that the three complexes form isotypic solid-state struc... |
12184779 | Supramolecular gold(I) thiobarbiturate chemistry: combining aurophilicity and hydrogen bonding to make polymers, sheets, and networks. | The cooperative forces of aurophilic and hydrogen bonding have been used in the self-assembly of phosphine or diphosphine complexes of gold(I) with the thiolate ligands derived from 2-thiobarbituric acid, SC(4)H(4)N(2)O(2), by single or double deprotonation. The reaction of the corresponding gold(I) trifluoroacetate co... |
12184755 | Excited-state electronic coupling and photoinduced multiple electron transfer in two related ligand-bridged hexanuclear mixed-valence compounds. | The synthesis, characterization, electrochemical, photophysical, and photochemical properties of two hexanuclear mixed-valence compounds are reported. Each supramolecular species consists of two cyano-bridged [(NC)(5)Fe(II)-CN-Pt(IV)(NH(3))(3)L-NC-Fe(II)(CN)(5)] triads that are linked to each other through a Pt(IV)-L-P... |
12184749 | Lead(II) complexes with macrocyclic receptors derived from 4,13-diaza-18-crown-6. | The complexation properties of three related macrocycles derived from 4,13-diaza-18-crown-6 toward lead(II) are reported. The flexible macrocycle N,N'-bis(2-aminobenzyl)-4,13-diaza-18-crown-6 (L(2)) forms stable complexes with this metal ion in the presence of different counterions (perchlorate and thiocyanate). The X-... |
12182967 | Cannabinoids in the treatment of glaucoma. | The leading cause of irreversible blindness is glaucoma, a disease normally characterized by the development of ocular hypertension and consequent damage to the optic nerve at its point of retinal attachment. This results in a narrowing of the visual field, and eventually results in blindness. A number of drugs are ava... |
12182584 | Calix[4]arene-functionalized naphthalene and perylene imide dyes. | [reaction: see text] Calix[4]arenes bearing one, two, or four 1,8-naphthyl imide groups at the wide rim and bis-calix[4]arenes connected via perylene-bisimide dye spacers have been synthesized. The low-temperature NMR spectrum of the tetranaphthylimide suggests, in agreement with a crystal structure, a C2-symmetrical p... |
12182682 | Synthesis of poly(alkyl aryl ether) dendrimers. | Poly(alkyl aryl ether) dendrimers of up to four generations composed of a phloroglucinol core, branching components, and pentamethylene spacers are synthesized by a divergent growth methodology. A repetitive synthetic sequence of phenolic O-alkylation and O-benzyl deprotection reactions are adopted for the synthesis of... |
12182660 | Anion effects on the recognition of ion pairs by calix[4]arene-based heteroditopic receptors. | A novel heteroditopic receptor (5) based on a rigid calix[4]arene cavity bearing at the upper rim four arylsulfonamido binding sites has been synthesized. The binding abilities of this new host have been investigated in apolar solvents toward a series of tetramethylammonium salts (tosylate, chloride, acetate, trifluoro... |
12182654 | Functionalization of the methylene groups of p-tert-butylcalix[4]arene: S-C, N-C, and C-C bond formation. | Reaction of the calixarene derivative 7 with two exocyclic double bonds with carbon-, nitrogen-, oxygen-, or sulfur-containing nucleophiles afforded bis(spirodienone) derivatives substituted at two opposite methylene groups in a trans fashion. LiAlH(4) reduction of the bis(spirodienone) derivatives with two methylenes ... |
12182620 | Synthesis and self-inclusion of bipyridine-spaced cyclodextrin dimers. | The synthesis and conformational behavior of two cyclodextrin dimers containing aromatic bipyridine spacers is presented. The proton NMR spectra of these dimers in aqueous solution show a doubling of signals in the aromatic region due to complete or partial self-inclusion of the spacer. The degree and the strength of s... |
12183058 | Translocation of pyrene-labeled phosphatidylserine from the plasma membrane to mitochondria diminishes systematically with molecular hydrophobicity: implications on the maintenance of high phosphatidylserine content in the inner leaflet of the plasma membrane. | To study the translocation of phosphatidylserine (PS) from plasma membrane to mitochondria, dipyrene PS molecules (diPyr(n)PS; n=acyl chain length) were introduced to the plasma membrane of baby hamster kidney cells (BHK cells) using either cyclodextrin-mediated monomer transfer or fusion of cationic vesicles. Transloc... |
12181349 | Identification of the functional domains of yeast sorting nexins Vps5p and Vps17p. | Sorting nexins (Snxs) are a recently discovered family of conserved hydrophilic cytoplasmic proteins that have been found associated with membranes of the endocytic system and that are implicated in the trafficking of many endosomal membrane proteins, including the epidermal growth factor receptor and transferrin recep... |
12180904 | Synthesis of a 56 component library of sugar beta-peptides. | Many biological processes of vital importance are triggered by the molecular recognition of small carbohydrate units by proteins and receptors thus leading to the belief that carbohydrates could act as candidates for the design of new drugs. We have developed a new useful synthetic approach, which can be applied in a c... |
12181675 | Folding of the rabbit hemorrhagic disease virus capsid protein and delineation of N-terminal domains dispensable for assembly. | Rabbit hemorrhagic disease virus (RHDV) and European brown hare syndrome virus (EBHSV) are caliciviruses that produce severe symptoms and are lethal to rabbits and hares. The folding of the capsid protein was studied by determination of the antigenic pattern of chimeric capsid proteins, composed of regions from RHDV an... |
12177310 | Determination of affinity, stoichiometry and sequence selectivity of minor groove binder complexes with double-stranded oligodeoxynucleotides by electrospray ionization mass spectrometry. | Electrospray mass spectrometry was evaluated regarding the reliability of the determination of the stoichiometries and equilibrium association constants from single spectra. Complexes between minor groove binders (Hoechst 33258, Hoechst 33342, DAPI, netropsin and berenil) and 12mer oligonucleotide duplexes with a centr... |
12177225 | Decreased neuronal synchronization during experimental seizures. | Synchronization between CA1 pyramidal neurons was studied using dual-cell patch-clamp techniques simultaneous with an extracellular measurement of network activity. We explored various linear and nonlinear methods to detect weak synchronization in this network, using cross-correlation, mutual information in one and two... |
12177215 | Genetic influence on quantitative features of neocortical architecture. | The layout of functional cortical maps exhibits a high degree of interindividual variability that may account for individual differences in sensory and cognitive abilities. By quantitatively assessing the interindividual variability of orientation preference columns in the primary visual cortex, we demonstrate that col... |
12177211 | The neural cell adhesion molecule regulates cell-surface delivery of G-protein-activated inwardly rectifying potassium channels via lipid rafts. | Mice deficient in the neural cell adhesion molecule (NCAM) exhibit increased anxiety and anxiolytic sensitivity to serotonin 5-HT1A receptor agonists. Here, we investigate the relationship between NCAM and 5-HT1A receptor signaling pathways modulating G-protein-activated inwardly rectifying K+ (Kir3) channels. When stu... |
12177179 | Synthesis and biochemical properties of a new photoactivatable cholesterol analog 7,7-azocholestanol and its linoleate ester in Chinese hamster ovary cell lines. | We report the chemical synthesis of a new photoactivatable cholesterol analog 7,7-azocholestanol (AC) and its linoleate ester (ACL). We also examined the biochemical properties of the sterol and its ester by employing several different mutant Chinese hamster ovary (CHO) cell lines with defined abnormalities in choleste... |
12175753 | Cyclodextrin conjugate-based controlled release system: repeated- and prolonged-releases of ketoprofen after oral administration in rats. | 6(A)-O-[2-(3-Benzoylphenyl)propinoyl]-alpha-cyclodextrin (KP-alpha-CyD conjugate), in which an anti-inflammatory drug, ketoprofen (KP), is covalently bound to one of the primary hydroxyl groups of alpha-cyclodextrin, was prepared, and its release behavior in vitro and in vivo was investigated. Further, the CyD conjugat... |
12175256 | Static and dynamic behavior of 2:1 inclusion complexes of cyclodextrins and charged porphyrins in aqueous organic media. | Two heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin (TMe-beta-CD) molecules strongly include the peripheral substituents at the 5- and 15-positions of the charged meso-tetrasubstituted porphyrins, PorSub(4) [TPPS(4) (Sub = p-C(6)H(4)-SO(3)(-)), TPPOC3PS (p-C(6)H(4)-O-(CH(2))(3)-p-C(6)H(4)-SO(3)(-)), TCPP (Sub = p-C(6)H(... |
12175254 | Photoinduced electron transfer in a rigid first generation triphenylamine core dendrimer substituted with a peryleneimide acceptor. | The electron-transfer process of a first generation dendrimer with a triphenylamine core substituted with one peryleneimide chromophore at the rim (N1P1) was investigated by steady-state and time-resolved spectroscopic techniques in two different solvents of medium and low polarity. Single photon counting experiments s... |
12175224 | Bis(PheOH) maleic acid amide-fumaric acid amide photoizomerization induces microsphere-to-gel fiber morphological transition: the photoinduced gelation system. | The photoinduced gelation system based on 1 (non-gelling) to 2 (gelling) molecular photoisomerization in water results by microspheres (1) to gel fibers (2) transformation at the supramolecular level. |
12175222 | Amplified optical nonlinearity in a self-assembled double-strand conjugated porphyrin polymer ladder. | Addition of 4,4'-bipyridyl to a solution of a meso-meso butadiyne-linked conjugated zinc porphyrin polymer in chloroform results in self-assembly of a double-strand ladder complex. Excess ligand causes this duplex to dissociate into single strands. These binding processes were elucidated by near-IR and NMR titrations, ... |
12175215 | Hyperbranched molecular nanocapsules: comparison of the hyperbranched architecture with the perfect linear analogue. | The results of a comparative study of hyperbranched, partially esterified polyglycerols with their linear polyglycerol analogues with respect to molecular encapsulation and phase transfer are reported. Two hyperbranched polyglycerol samples with molecular weights of 3000 and 8000 g/mol (Mw/Mn = 1.3), respectively, have... |
12176304 | Slow-release melarsoprol microparticles. | The present study compares two methods of preparation of microparticles of melarsoprol for the treatment of the human trypanosomiasis. Melarsoprol is poorly soluble in water and in organic media. Microparticles were formulated with modified O/W and W/O/W methods, Poly(epsilon -caprolactone) microparticles were prepared... |
12176299 | Effect of inclusion complexation with cyclodextrins on photostability of nifedipine in solid state. | Nifedipine is a highly photosensitive drug that requires restricted protection from light during manufacturing, storage and handling of its dosage forms. Inclusion complexation of nifedipine with cyclodextrins (CDs) could be advantageous in protecting the drug against the effect of light. In this study, solid inclusion... |
12176268 | Influence of chemical structure of amphiphilic beta-cyclodextrins on their ability to form stable nanoparticles. | The aim of the study was to establish a correlation between the chemical structure of amphiphilic beta-cyclodextrins (beta-CDa) and their ability to form stable nanospheres. Amphiphilic derivatives were obtained according to an optimized well-known three-step synthesis. The selective acylation of the secondary face of ... |
12176224 | Carboxyethylester-polyrotaxanes as a new calcium chelating polymer: synthesis, calcium binding and mechanism of trypsin inhibition. | A carboxyethylester-polyrotaxane was synthesized as a novel calcium chelating polymer in the field of oral drug delivery and characterized in terms of mechanism of trypsin inhibition. Here, carboxyethylester (CEE) groups are introduced to all the primary hydroxyl groups in alpha-cyclodextrins (alpha-CDs), which are thr... |
12175149 | Metal ion-sensitive holographic sensors. | Holographic sensors for Na+ and K+ have been fabricated from crown ethers incorporated into polymeric hydrogels. The methacrylate esters of a homologous series of hydroxyether crown ethers were synthesized and copolymerized with hydroxyethyl methacrylate and the cross-linker ethylene dimethacrylate (3 mol %) to form st... |
12173931 | Identification of key amino acid residues in the assembly of enzymes into the pyruvate dehydrogenase complex of Bacillus stearothermophilus: a kinetic and thermodynamic analysis. | Structural studies have shown that electrostatic interactions play a major part in the binding of dihydrolipoyl dehydrogenase (E3) to the peripheral subunit-binding domain (PSBD) of the dihydrolipoyl acyltransferase (E2) in the assembly of the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus. T... |
12172052 | Double high-dose chemotherapy with autologous stem cell transplantation in patients with high-risk neuroblastoma: a pilot study in a single center. | Double high-dose chemotherapy (HDCT) was applied to 18 patients with highrisk neuroblastoma including 14 patients who could not achieve complete response (CR) even after the first HDCT. In 12 patients, successive double HDCT was rescued with peripheral blood stem cells collected during a single round of leukaphereses a... |
12171563 | Integrated acquisition of analytical and biopharmaceutical screening data for beta-adrenergic-drugs employing diversified macrocycle supported potentiometric detection in HPLC systems. | Potentiometric detection with poly(vinyl chloride) (PVC) based liquid membrane electrode coatings is presented for a series of eighteen beta-adrenoceptor binding drugs (five agonists and thirteen antagonists) in cation exchange-HPLC and RP-HPLC systems. Incorporation of lipophilic cation-exchanger tetrakis(p-chlorophen... |
12171786 | Cholesterol depletion disrupts caveolae and differentially impairs agonist-induced arterial contraction. | <h4>Objective</h4>This study assessed the role of cholesterol-rich membrane regions, including caveolae, in the regulation of arterial contractility. Methods and Results- Rat tail artery devoid of endothelium was treated with the cholesterol acceptor methyl-beta-cyclodextrin, and the effects on force and Ca2+ handling ... |
12170819 | A polycationic dendrimer as noncovalent support for anionic organometallic complexes. | Polycationic dendrimer 1 forms a well-defined, stoichiometric assembly with eight anionic metal complexes; this assembly is successfully applied as a Lewis acidic catalyst which performs comparably to the unsupported metal complex. |
12170799 | A facile synthesis of novel types of cyclodextrin derivatives by insertion of an aromatic dicarbonyl spacer into a permethylated alpha-cyclodextrin skeleton. | Novel types of cyclodextrin derivatives are easily synthesized by the insertion of an aromatic dicarbonyl spacer into the skeleton of permethylated alpha-cyclodextrin, and the isophthaloyl-inserted one shows almost the same complexing ability toward p-nitrophenol as permethylated beta-cyclodextrin. |
12170796 | Configurational assignment of alpha-chiral carboxylic acids by complexation to dimeric Zn-porphyrin: host-guest structure, chiral recognition and circular dichroism. | A circular dichroic (CD) excition chirality method based on host-guest chiral recognition has been developed to determine the absolute configuration of carboxylic acids with an alpha-stereogenic center; an amide C = O-->Zn coordination, identified by infrared spectroscopy and computations, is involved in this complexat... |
12169629 | Diverse recognition of non-PxxP peptide ligands by the SH3 domains from p67(phox), Grb2 and Pex13p. | The basic function of the Src homology 3 (SH3) domain is considered to be binding to proline-rich sequences containing a PxxP motif. Recently, many SH3 domains, including those from Grb2 and Pex13p, were reported to bind sequences lacking a PxxP motif. We report here that the 22 residue peptide lacking a PxxP motif, de... |
12166930 | Synthesis, biological properties, and molecular modeling investigation of the first potent, selective, and water-soluble human A(3) adenosine receptor antagonist. | A new, highly potent, selective, and water-soluble antagonist of the hA(3) adenosine receptor was synthesized and tested in binding and functional assays. Compound 4 (5-[[(4-pyridyl)amino]carbonyl]amino-8-methyl-2-(2-furyl)-pyrazolo[4,3-e]1,2,4-triazolo[1,5-c]pyrimidine hydrochloride) displayed high water solubility (1... |
12167061 | Theoretical study on second hyperpolarizabilities of phenylacetylene dendrimer: toward an understanding of structure-property relation in NLO responses of fractal antenna dendrimers. | This contribution explores the relation between molecular second hyperpolarizabilities (gamma) and molecular architecture in phenylacetylene dendrimers using the semiempirical molecular orbital method, that is, INDO/S method. The orientationally averaged gamma of a large-size phenylacetylene dendrimer, which is compose... |
12167053 | Charge transport in photofunctional nanoparticles self-assembled from zinc 5,10,15,20-tetrakis(perylenediimide)porphyrin building blocks. | Molecules designed to carry out photochemical energy conversion typically employ several sequential electron transfers, as do photosynthetic proteins. Yet, these molecules typically do not achieve the extensive charge transport characteristic of semiconductor devices. We have prepared a large molecule in which four per... |
12167052 | Flexible sorption and transformation behavior in a microporous metal-organic framework. | Crystals of the metal-organic framework material Ni(2)(4,4'-bipyridine)(3)(NO(3))(4) (A) have been grown by reaction of Ni(NO(3))(2).6H(2)O and 4,4'-bipyridine in methanol solution. Single-crystal X-ray diffraction experiments show that the ladder structure of the framework is maintained after desolvation of the materi... |
12167015 | Unusual electrochemical properties of unsymmetric viologen dendrimers. | A new series of redox-active dendrimers containing a single 4,4'-bipyridinium (viologen) group covalently attached to the focal point of Newkome-type dendrons (first to third generation) has been prepared and characterized. The electrochemical properties of these unsymmetric dendrimers show two unusual aspects. First, ... |
12167014 | Self-assembly of dipeptidyl ureas: a new class of hydrogen-bonded molecular duplexes. | The dipeptidyl urea 1 composed of two dipeptide chains bearing the C-terminal pyridyl moiety (-L-Ala-L-Pro-NHPy) was prepared. Two molecules of 1 are revealed to be held together by six intermolecular hydrogen bonds to form a hydrogen-bonded duplex by the single-crystal X-ray structure determination. Proton magnetic re... |
12163558 | Blocking of HIV-1 infection by targeting CD4 to nonraft membrane domains. | Human immunodeficiency virus (HIV)-1 infection depends on multiple lateral interactions between the viral envelope and host cell receptors. Previous studies have suggested that these interactions are possible because HIV-1 receptors CD4, CXCR4, and CCR5 partition in cholesterol-enriched membrane raft domains. We genera... |
12163173 | Supramolecular organization of photosystem I and light-harvesting complex I in Chlamydomonas reinhardtii. | We report a structural characterization by electron microscopy and image analysis of a supramolecular complex consisting of photosystem I and light-harvesting complex I from the unicellular green alga Chlamydomonas reinhardtii. The complex is a monomer, has longest dimensions of 21.3 and 18.2 nm in projection, and is s... |
12163073 | Modeling the lipid component of membranes. | During the past several years, there have been a number of advances in the computational and theoretical modeling of lipid bilayer structural and dynamical properties. Molecular dynamics (MD) simulations have increased in length and time scales by about an order of magnitude. MD simulations continue to be applied to mo... |
12163069 | Designing supramolecular protein assemblies. | Many natural proteins self-assemble, either to fulfill their biological function or as part of a pathogenic process. Biological assembly phenomena such as amyloidogenesis, domain swapping and symmetric oligomerization are inspiring new strategies for designing proteins that self-assemble to form supramolecular complexe... |
12162747 | Cholesterol levels modulate EGF receptor-mediated signaling by altering receptor function and trafficking. | A variety of signal transduction pathways including PI turnover, MAP kinase activation, and PI 3-kinase activation have been shown to be affected by changes in cellular cholesterol content. However, no information is available regarding the locus (or loci) in the pathways that are susceptible to modulation by cholester... |
12023906 | Assembling amyloid fibrils from designed structures containing a significant amyloid beta-peptide fragment. | The amyloid plaque, consisting of amyloid beta-peptide (Abeta) fibrils surrounded by dystrophic neurites, is an invariable feature of Alzheimer's disease. The determination of the molecular structure of Abeta fibrils is a significant goal that may lead to the structure-based design of effective therapeutics for Alzheim... |
12020345 | Polyamine-modulated factor 1 binds to the human homologue of the 7a subunit of the Arabidopsis COP9 signalosome: implications in gene expression. | Polyamines have been identified to play a role in the transcription of various growth-related genes. The recently discovered polyamine responsive element and the associated trans-acting proteins involved in polyamine-regulated transcription have provided a model system for the study of the role of polyamines in transcr... |
11985496 | The C-terminal, third conserved motif of the protein activator PACT plays an essential role in the activation of double-stranded-RNA-dependent protein kinase (PKR). | One of the key mediators of the antiviral and antiproliferative actions of interferon is double-stranded-RNA-dependent protein kinase (PKR). PKR activity is also involved in the regulation of cell proliferation, apoptosis and signal transduction. We have recently identified PACT, a novel protein activator of PKR, as an... |
12163008 | An effective anticonvulsant prepared following a host-guest strategy that uses hydroxypropyl-beta-cyclodextrin and benzaldehyde semicarbazone. | The convulsions of approximately 25% of epileptics are inadequately controlled by currently available medication; therefore the preparation of new antiepileptic drugs is of great interest. Aryl semicarbazones can be considered a new class of compounds presenting anticonvulsant activity. In addition, they can be orally ... |
12161403 | Efficacy of parenteral itraconazole against disseminated Candida albicans infection in two mouse strains. | The efficacy of a new cyclodextrin intravenous formulation of itraconazole was evaluated by intraperitoneal treatment of experimental disseminated Candida albicans infections in BALB/c and DBA/2 mice. Mice were treated with doses of 5 or 20 mg/kg for 14 days and observation was continued for 28 days. Mice were randomly... |
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