id stringlengths 4 8 | title stringlengths 1 642 | abstract stringlengths 50 17.9k |
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12012410 | A highly regioselective approach to multiple adducts of C60 governed by strain minimization of macrocyclic malonate addends. | New macrocyclic malonates 2-5 have been prepared by reaction of malonyl dichloride with alkanediols. Reactions of these cyclo-[n]-alkylmalonates with C60 are highly regioselective. The macrocycles containing identical alkyl spacers selectively form bis- and trisadducts of C60 with rotational symmetry. The addition patt... |
12012408 | Smectic liquid crystals from supramolecular guanidinium alkylbenzenesulfonates. | A homologous series of guanidinium alkylbenzenesulfonates from ethyl to tetradecyl were synthesized and characterised. Their thermotropic polymorphism was investigated by polarizing optical microscopy, differential scanning calorimetry, and dilatometry. The structure of the smectic liquid crystal phases obtained at hig... |
12012406 | Competing supramolecular interactions give a new twist to terpyridyl chemistry: anion- and solvent-induced formation of spiral arrays in silver(I) complexes of a simple terpyridine. | Multiple competing molecular interactions (metal-ligand, pi-stacking and hydrogen-bonding) in the silver(I) complexes of 4'-thiomethyl-2,2':6',2"-terpyridine give rise to a range of different molecular architectures, in which the metal-ligand coordination requirements are satisfied in quite different ways. Polynuclear ... |
12012405 | 1,3,5-2,4,6-functionalized, facially segregated benzenes-exploitation of sterically predisposed systems in supramolecular chemistry. | In the present article, we introduce the unique steric features of 1,3,5-substituted triethylbenzenes as a design principle for host molecules and supramolecular systems. Due to steric gearing, all three functional substituents are disposed on the same side of the phenyl plane. The use of this benzene scaffold has lead... |
12007179 | Enantioselective binding and stable encapsulation of alpha-amino aids in a helical poly(L-glutamic acid)-shelled dendrimer in aqueous solutions. | A novel water-soluble peptide-shelled dendrimer containing a poly(L-glutamic acid) segment grafted on the third-generation poly(amido amine) dendrimer was successfully synthesized, and its secondary structural properties and interaction with alpha-amino acids (Trp, Phe, and Tyr) were revealed by spectroscopic measureme... |
12007177 | New dendrimer-peptide host-guest complexes: towards dendrimers as peptide carriers. | Adamantyl urea and adamantyl thiourea modified poly(propylene imine) dendrimers act as hosts for N-terminal tert-butoxycarbonyl (Boc)-protected peptides and form chloroform-soluble complexes. Investigations with NMR spectroscopy show that the peptide is bound to the dendrimer by ionic interactions between the dendrimer... |
12022855 | Surface forces, supramolecular polymers, and inversion symmetry. | The effects of supramolecular equilibrium polymers on surface forces are studied by both a phenomenological Landau type analysis and a molecular model based on a Bethe-Guggenheim approximation. We point out that surface forces brought about by equilibrium polymers may be completely different from what can be found with... |
12022846 | Electroluminescent zinc(II) bis(8-hydroxyquinoline): structural effects on electronic states and device performance. | We present direct evidence for stable oligomers in vacuum-deposited thin films of zinc(II) bis(8-hydroxyquinoline) (Znq(2)). The tetramer [(Znq(2))(4)] is the energetically favored configuration in both the single crystal and the vacuum-deposited thin film. Oligomerization leads to distinct, symmetry-driven differences... |
12022844 | Iron complexes capped with dendrimer-appended triazacyclononanes as the novel spatially encumbered models of non-heme iron proteins. | Poly(benzyl ether) dendrimers with a 1,4,7-triazacyclononane (TACN) focal core (Ln(3)TACN, 2a-4a) and nondendritic L1(3)TACN (1a), upon reaction with FeCl(2), followed by NaOAc and NH(4)PF(6), afforded mononuclear iron(II) complexes [Fe(II)(eta(2)-OAc)(Ln(3)TACN)](+) (1b-4b), which were oxidized under O(2) to form dinu... |
12022837 | Stable polymeric nanoballoons: lyophilization and rehydration of cross-linked liposomes. | The cross-linking of supramolecular assemblies of hydrated lipids is an effective method to stabilize these assemblies to disruption by surfactants or aqueous alcohol. The heterobifunctional lipids, Acryl/DenPC(16,18) and Sorb/DenPC(18,21), are examples of a new class of polymerizable lipid designed for the creation of... |
12022831 | Synthesis and characterization of carbohydrate-based phospholipids. | Novel carbohydrate-based phospholipids containing two saturated C(12) (dilauroyl ribo-phosphocholine) (DLRPC), C(14) (dimyristoyl ribo-phosphocholine) (DMRPC), and C(20) (diarachadonyl ribo-phosphocholine) (DARPC) carboxylic acid chains were synthesized. The physical properties of the supramolecular structures formed b... |
12022883 | Mitochondrial aconitase modification, functional inhibition, and evidence for a supramolecular complex of the TCA cycle by the renal toxicant S-(1,1,2,2-tetrafluoroethyl)-L-cysteine. | Metabolism of the common industrial gas tetrafluoroethylene in mammals results in the formation of S-(1,1,2,2)-tetrafluoroethyl-L-cysteine (TFEC), which can be bioactivated by a mitochondrial C-S lyase commonly referred to as beta-lyase. The resultant "reactive intermediate", difluorothioacetyl fluoride (DFTAF), is a p... |
12022223 | Mutation Master: profiles of substitutions in hepatitis C virus RNA of the core, alternate reading frame, and NS2 coding regions. | The RNA genome of the hepatitis C virus (HCV) undergoes rapid evolutionary change. Efforts to control this virus would benefit from the advent of facile methods to identify characteristic features of HCV RNA and proteins, and to condense the vast amount of mutational data into a readily interpretable form. Many HCV seq... |
12021304 | CD8alpha- CD11b+ dendritic cells present exogenous virus-like particles to CD8+ T cells and subsequently express CD8alpha and CD205 molecules. | Recombinant porcine parvovirus virus-like particles (PPV-VLPs) are particulate exogenous antigens that induce a strong, specific cytotoxic T lymphocyte (CTL) response in the absence of adjuvant. In the present report, we demonstrate in vivo that dendritic cells (DCs) present PPV-VLPs to CD8+ T cells after intracellular... |
12019973 | The unusually high proton affinity of aza-18-crown-6 ether: implications for the molecular recognition of lysine in peptides by lariat crown ethers. | Recent studies have shown that 18-crown-6 ether (18C6) will selectively form adducts in the gas phase with small, lysine containing peptides. The present study extends this work by investigating the ability of aza-18-crown-6 ether (A18C6) and L1 (a simple lariat crown ether derivative of A18C6) to form similar noncoval... |
12019250 | A reaction-diffusion model for interference in meiotic crossing over. | One crossover point between a pair of homologous chromosomes in meiosis appears to interfere with occurrence of another in the neighborhood. It has been revealed that Drosophila and Neurospora, in spite of their large difference in the frequency of crossover points, show very similar plots of coincidence-a measure of t... |
12014951 | Structure-activity relationships at human and rat A2B adenosine receptors of xanthine derivatives substituted at the 1-, 3-, 7-, and 8-positions. | In the search for improved selective antagonist ligands of the A2B adenosine receptor, which have the potential as antiasthmatic or antidiabetic drugs, we have synthesized and screened a variety of alkylxanthine derivatives substituted at the 1-, 3-, 7-, and 8-positions. Competition for 125I-ABOPX (125I-3-(4-amino-3-io... |
12011427 | Headpiece domain of dematin is required for the stability of the erythrocyte membrane. | Dematin is an actin-binding and bundling protein of the erythrocyte membrane skeleton. Dematin is localized to the spectrin-actin junctions, and its actin-bundling activity is regulated by phosphorylation of cAMP-dependent protein kinase. The carboxyl terminus of dematin is homologous to the "headpiece" domain of villi... |
12011426 | Looped out and perpendicular: deformation of Watson-Crick base pair associated with actinomycin D binding. | Many anticancer drugs interact directly with DNA to exert their biological functions. To date, all noncovalent, intercalating drugs interact with DNA exclusively by inserting their chromophores into base steps to form elongated and unwound duplex structures without disrupting the flanking base pairs. By using actinomyc... |
12010065 | The first precise molecular structure of a monomeric transition metal cyanide, copper(I) cyanide. | Copper(I) cyanide is an important reagent in organic, organometallic, and supramolecular chemistry because of both the copper center and the versatile cyanide ligand. Solid-phase CuCN and many of its derivatives show oligomeric or polymeric structures, a trait shared by other metal cyanides. Often, it is difficult to s... |
12010040 | Conformationally constrained macrocycles that mimic tripeptide beta-strands in water and aprotic solvents. | The beta-strand conformation is unknown for short peptides in aqueous solution, yet it is a fundamental building block in proteins and the crucial recognition motif for proteolytic enzymes that enable formation and turnover of all proteins. To create a generalized scaffold as a peptidomimetic that is pre-organized in a... |
12010770 | Physiological antagonism between ventricular beta 1-adrenoceptors and alpha 1-adrenoceptors but no evidence for beta 2- and beta 3-adrenoceptor function in murine heart. | 1. Murine left atrium lacks inotropic beta(2)-adrenoceptor function. We investigated whether beta(2)-adrenoceptors are involved in the cardiostimulant effects of (-)-adrenaline on spontaneously beating right atria and paced right ventricular myocardium of C57BL6 mice. We also studied a negative inotropic effect of (-)-... |
12009473 | Specific natural DNA-bound lipids in post-genome era. The lipid conception of chromatin organization. | Two pools of DNA-bound lipids were isolated from DNA supramolecular complex (SC-DNA): loosely bound (extracted with 35% ethanol) and tightly bound lipids (extracted after additional treatment DNase I). The compositions of the two lipid pools from different sources (rat thymus, liver, loach sperm, pigeon erythrocytes, Z... |
12009470 | Electrochemical studies of blocking properties of solid supported tethered lipid membranes on gold. | The insulating properties of self-assembled thiolipid monolayers and tethered lipid bilayers on polycrystalline gold electrodes were studied by means of cyclic voltammetry (CV). These films were formed by two-step self-assembly processes. Electrochemical measurements of the heterogeneous electron transfer rate constant... |
12009457 | Affinity assembled multilayers for new dehydrogenase biosensors. | We propose a novel approach, which allows the control of the spatial arrangement of redox mediator, coenzyme and enzyme on the electrode at a molecular level, using essentially electrostatic interactions. The first step consists of adsorbing a monolayer of molecules out of a new family of redox mediators, substituted n... |
12009452 | A comparative thermodynamic study for both natural and artificial RNA/DNA-protein binary complexes. | In recent years, Systematic Evolution of Ligands by EXponential enrichment (SELEX) technique has been developed into a fast growing field. In contrast to traditional recognition elements, like antibody, our interests focus on novel molecular recognition elements based on nucleic acids, which are of value both for the t... |
12009964 | Transition metal-carbonyl labeling of biotin and avidin for use in solid-phase carbonyl metallo immunoassay (CMIA). | The preparation of several transition metal-carbonyl tracers of biotin and avidin is described. Multiple labeling of avidin was achieved by acylation of some of its amine-bearing residues with N-succinimidyl 4-pentynoate (dicobalt hexacarbonyl). By varying the initial amount of this complex, protein conjugates with the... |
12009957 | Dendrimers as carrier protein mimetics for IgE antibody recognition. Synthesis and characterization of densely penicilloylated dendrimers. | The synthesis of benzylpenicilloyl-containing dendrimers has been achieved by a convenient procedure involving quantitative functionalization of the terminal amino groups of the three Starbust PAMAM generations used (G(n); n = 0, 1, 2). All these densely penicilloylated dendrimers (G(n)P) exhibit similar, simple NMR sp... |
12009955 | Development of a nonviral gene delivery vehicle for systemic application. | Polycation vehicles used for in vitro gene delivery require alteration for successful application in vivo. Modification of polycations by direct grafting of additional components, e.g., poly(ethylene glycol) (PEG), either before or after DNA complexation, tend to interfere with polymer/DNA binding interactions; this is... |
12009949 | Inhibitory effect of supramolecular polyrotaxane-dipeptide conjugates on digested peptide uptake via intestinal human peptide transporter. | The effect of polyrotaxane-dipeptide (Val-Lys) conjugates on the uptake of a model dipeptide (Gly-Sar) was examined via human peptide transporter (hPEPT1) on HeLa cells. Here, Val-Lys groups are introduced to alpha-CDs, which are threaded onto a poly(ethylene oxide) chain capped with bulky end-groups (polyrotaxane). Th... |
12009933 | Polyester dendritic systems for drug delivery applications: in vitro and in vivo evaluation. | High molecular weight polymers (> 20 000 Da) have been widely used as soluble drug carriers to improve drug targeting and therapeutic efficacy. Dendritic polymers are exceptional candidates for the preparation of near monodisperse drug carriers due to their well-defined structure, multivalency, and flexibility for tail... |
12009926 | Effect of heme structure on O(2)-binding properties of human serum albumin-heme hybrids: intramolecular histidine coordination provides a stable O(2)-adduct complex. | 5,10,15,20-Tetrakis[(alpha,alpha,alpha,alpha-o-pivaloylamino)phenyl]porphinatoiron(II) and 5,10,15,20-tetrakis([alpha,alpha,alpha,alpha-o-(1-methylcyclohexanoylamino)]phenyl)porphinatoiron(II) complexes bearing a covalently bound 8-(2-methyl-1-imidazolyl)octanoyloxymethyl or 4-(methyl-L-histidinamido)butanoyloxymethyl ... |
12009898 | Cellular cholesterol stimulates acute uptake of palmitate by redistribution of fatty acid translocase in type II pneumocytes. | Cholesterol is an abundant lipid of lung surfactant, where its concentration changes relative to phospholipids in response to certain physiological conditions. We investigated the effect of the cellular cholesterol content on uptake and esterification of palmitic acid, and on cellular distribution of fatty acid translo... |
12008156 | Study on the inclusion complexes of bromazepam with beta- and beta-hydroxypropyl-cyclodextrins. | Solubility enhancement of the water insoluble bromazepam was studied during the formation of its inclusion complexes with beta-cyclodextrin (beta-CD) and beta-hydroxypropyl-cyclodextrin (beta-HP-CD). The phase solubility technique established by Higuchi and Connors and UV-spectrophotometric methods (zero- and second-or... |
12008898 | Matrix attachment regions (MARs) enhance transformation frequencies and reduce variance of transgene expression in barley. | Nuclear matrix attachment regions (MARs) are defined as genomic DNA sequences, located at the physical boundaries of chromatin loops. They are suggested to play a role in the cis unfolding and folding of the chromatin fibre associated with the regulation of gene transcription. Inclusion of MARs in transgene cassettes e... |
12006662 | Novel mechanism for regulation of epidermal growth factor receptor endocytosis revealed by protein kinase A inhibition. | Current models put forward that the epidermal growth factor receptor (EGFR) is efficiently internalized via clathrin-coated pits only in response to ligand-induced activation of its intrinsic tyrosine kinase and is subsequently directed into a lysosomal-proteasomal degradation pathway by mechanisms that include recepto... |
12005480 | Solid-phase synthesis of 1,2,5-trisubstituted 4-imidazolidinones. | An efficient method for the preparation of 1,2,5-trisubstituted 4-imidazolidinones is presented. The synthetic approach is based on the formation of an N-[1-(benzotriazol-1-yl)alkyl] moiety on the amino group of a MBHA resin-bound amino acid. The nucleophilic substitution of the benzotriazole group with an amidic nitro... |
12006495 | The dMi-2 chromodomains are DNA binding modules important for ATP-dependent nucleosome mobilization. | Drosophila Mi-2 (dMi-2) is the ATPase subunit of a complex combining ATP-dependent nucleosome remodelling and histone deacetylase activities. dMi-2 contains an HMG box-like region, two PHD fingers, two chromodomains and a SNF2-type ATPase domain. It is not known which of these domains contribute to nucleosome remodelli... |
12006486 | Synaptic multiprotein complexes associated with 5-HT(2C) receptors: a proteomic approach. | Membrane-bound receptors such as tyrosine kinases and ionotropic receptors are associated with large protein networks structured by protein-protein interactions involving multidomain proteins. Although these networks have emerged as a general mechanism of cellular signalling, much less is known about the protein comple... |
12005512 | Complex formation of cytochrome C with a calixarene carboxylic acid derivative: a novel solubilization method for biomolecules in organic media. | A calixarene carboxylic acid derivative has been found to form a complex with the cationic protein cytochrome c. The solubilized cytochrome c was stable and showed peroxidase activity in chloroform. The calix[6]arene and the calix[8]arene achieved quantitative extraction of the protein. The calix[6]arene, whose cavity ... |
12005356 | Estimation of cyclodextrin affinity to steroids. | A nonlinear spectrometric method for determination of the stability constant (Ks) for cyclodextrin complex with steroid was developed. The method is based on calculation of the parameters of competitive cyclodextrin complexation by simultaneous fitting of two types of curves. Those of the first type are the dependencie... |
12003528 | Crystal engineering of hydroxy group hydrogen bonding: design and synthesis of new diol lattice inclusion hosts. | The diols 7-11 have been synthesized, and their X-ray crystal structures determined, to learn how to influence and control lattice hydroxy group hydrogen bonding using crystal engineering ideas. To obtain new lattice inclusion hosts precise structural rules can be defined which enable the necessary supramolecular inter... |
12000300 | Cucurbit[7]uril: a very effective host for viologens and their cation radicals. | [reaction: see text] The host cucurbit[7]uril (CB7) forms very stable inclusion complexes with simple 4,4'-bipyridinium (viologen) dication guests in aqueous solution. The binding constants were measured by electronic absorption spectroscopy and found to be as high as 1 x 10(5) L/mol. One-electron reduction of the viol... |
12000274 | Self-assembly of molecular capsules in polar solvents. | [structure: see text] We present a novel type of molecular capsule formed by self-organization of calix[4]arenes with several oppositely charged functional groups located at their upper rims. In highly polar solvents, the complementary half-spheres form stable 1:1 complexes with association constants of up to 7 x 10(5)... |
12000838 | Thymine-methyl/pi interaction implicated in the sequence-dependent deformability of DNA. | The crystal structures of deoxy-oligonucleotides were retrieved from the Nucleic Acid Database and analyzed with the use of our program CHPI. The structure of 5'-ApTpApT-3' has been shown to be stabilized by the 5-methyl group in the thymidine moiety that favorably interacts with the adenine pi-ring preceding it. H2' o... |
11996582 | Template-directed self-assembly of 10-microm-sized hexagonal plates. | This article presents a strategy for the fabrication of ordered microstructures using concepts of design inspired by molecular self-assembly and template-directed synthesis. The self-assembling components are 4-microm-thick hexagonal metal plates having sides 10 microm in length ("hexagons"), and each template consists... |
11996576 | m-Diethynylbenzene macrocycles: syntheses and self-association behavior in solution. | m-Diethynylbenzene macrocycles (DBMs), buta-1,3-diyne-bridged [4(n)]metacyclophanes, have been synthesized and their self-association behaviors in solution were investigated. Cyclic tetramers, hexamers, and octamers of DBMs having exo-annular octyl, hexadecyl, and 3,6,9-trioxadecyl ester groups were prepared by intermo... |
11996561 | Self-organization of supramolecular complex composed of rigid dendritic porphyrin and fullerene. | A second-generation 1,3,5-phenylene-based dendritic porphyrin decorated with flexible alkyl chains exhibited a liquid crystallinity, and the inclusion of fullerene within the nanospace of the dendritic porphyrin strongly affected the mesophase structure in the thermotropic liquid-crystalline phase. |
11994415 | Escaping high viral load exhaustion: CD8 cells with altered tetramer binding in chronic hepatitis B virus infection. | Deletion, anergy, and a spectrum of functional impairments can affect virus-specific CD8 cells in chronic viral infections. Here we characterize a low frequency population of CD8 cells present in chronic hepatitis B virus (HBV) infection which survive in the face of a high quantity of viral antigen. Although they do no... |
11994058 | The roles of CYP2D6 and stereoselectivity in the clinical pharmacokinetics of chlorpheniramine. | <h4>Aims</h4>To examine the stereoselective disposition of chlorpheniramine and to evaluate the role of CYP2D6 in chlorpheniramine pharmacokinetics in humans.<h4>Methods</h4>Eight healthy volunteers (six extensive metabolizers with respect to CYP2D6 and two poor metabolizers) received a single 8 mg oral dose of rac-chl... |
11992692 | Physical properties and in vitro transfection efficiency of gene delivery vectors based on complexes of DNA with synthetic polycations. | Biophysical properties of polycation/DNA complexes designed for gene delivery were studied with respect to the conditions of their preparation, chemical structure and molecular weight of the polycations involved. The polycations used included a variety of cationic polymers and copolymers containing primary and tertiary... |
11992674 | Elongated supramolecular assemblies in drug delivery. | This review presents different lipid-based elongated microstructures: tubules, cochleate cylinders and ribbons. Their composition, process of preparation and the mechanism behind their formation is discussed as well as their use as a drug delivery system. |
11988396 | Determination of the free/included piroxicam ratio in cyclodextrin complexes: comparison between UV spectrophotometry and differential scanning calorimetry. | Few analytical techniques allow to evaluate the inclusion yield of cyclodextrin-drug complexes, because most manufacturing processes give amorphous products. In this study, we have developed an alternative method to differential scanning calorimetry, to accurately determine the free/complexed piroxicam ratio by UV spec... |
11988394 | Optimized conditions for MDCK permeability and turbidimetric solubility studies using compounds representative of BCS classes I-IV. | The solubility enhancing effects of various excipients, including their compatibility with in vitro permeability (P(app)) systems, was investigated using drugs representative of Biopharmaceutics Classification System (BCS) classes I-IV. Turbidimetric solubility determination using nephelometry and transport experiments... |
11985476 | Adenine nucleotide analogues locked in a Northern methanocarba conformation: enhanced stability and potency as P2Y(1) receptor agonists. | Preference for the Northern (N) ring conformation of the ribose moiety of nucleotide 5'-triphosphate agonists at P2Y(1), P2Y(2), P2Y(4), and P2Y(11) receptors, but not P2Y(6) receptors, was established using a ring-constrained methanocarba (a 3.1.0-bicyclohexane) ring as a ribose substitute (Kim et al. J. Med. Chem. 20... |
11986278 | Polyclonal antibodies to glutathione S-transferase--verotoxin subunit a fusion proteins neutralize verotoxins. | The A1 subunits of verotoxin-1 (VT1) and VT2 genes were cloned into pGEX-4T-2 for the expression of glutathione S-transferase (GST) fusion proteins. The N-terminal and the transmembrane regions of the A1 subunits were excluded from the constructs in order to increase the product yields. Polyclonal anti-VT1A1 and anti-V... |
11986273 | Quantitation of immunoglobulin to hepatitis E virus by enzyme immunoassay. | We developed a quantitative enzyme immunoassay (EIA) for antibody to hepatitis E virus (HEV) by using truncated HEV capsid protein expressed in the baculovirus system to improve seroepidemiology, to contribute to hepatitis E diagnosis, and to enable vaccine evaluations. Five antigen lots were characterized; we used a r... |
11982380 | Use of the pseudophase model in the interpretation of reactivity under restricted geometry conditions. An application to the study of the [Ru(NH(3))(5)pz](2+) + S(2)O(8)(2-) electron-transfer reaction in different microheterogeneous systems. | The title reaction has been studied under restricted geometry conditions, comprising aqueous solutions of a polymer (DNA), cyclodextrins, and dendrimers as well as (CTA)Cl micellar solutions and sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/water/oil microemulsions. The results are interpreted by taking as a general bas... |
11982378 | Bifunctional pincer-type organometallics as substrates for organic transformations and as novel building blocks for polymetallic materials. | The reactivity of the bifunctionalized ligand NC(Br)N-I 1 [IC(6)H(2)(CH(2)NMe(2))(2)-3,5-Br-4] has been studied as a versatile synthon for organic and/or organometallic synthesis. Chemoselective metalation (M = Pd, Pt, Li) at the C(aryl)-I or C(aryl)-Br bonds was achieved by choosing the appropriate metal precursors. I... |
11982366 | Radial control of recognition and redox processes with multivalent nanoparticle hosts. | Mixed Monolayer Protected Gold Clusters (MMPCs) featuring both hydrogen bonding and aromatic stacking molecular recognition functionalities have been used to create multivalent hosts for flavins. Multitopic binding of these hosts to flavin was shown to have a strong radial dependence: when the recognition site was brou... |
11982364 | Chromophore formation in resorcinarene solutions and the visual detection of mono- and oligosaccharides. | The colorimetric properties of resorcinarene solutions had not been investigated since Baeyer's initial synthesis. We recently reported that solutions containing resorcinarene macrocycles develop color upon heating or standing. In the presence of saccharides, these solutions exhibit significant color changes which are ... |
11982428 | Inclusion complex of conjugated linoleic acid (CLA) with cyclodextrins. | Conjugated linoleic acid (CLA) inclusion complexes with alpha-cyclodextrin (alpha-CD), beta-cyclodextrin (beta-CD), and gamma-cyclodextrin (gamma-CD) (designated CLA/CDs inclusion complexes) were prepared to determine the mole ratio of CLA complexed with CDs and the oxidative stability of CLA in the CLA/CDs inclusion c... |
11982410 | Recovery and characterization of the metal polymeric organic fraction (polymerin) from olive oil mill wastewaters. | A dark and complex metal polymeric organic mixture, named polymerin, was recovered from olive oil mill wastewaters (OMWW) and characterized by chemical analysis, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and atomic absorption spectrometry (AAS). Polymerin proved to be composed of carbohydrat... |
11981034 | Molecular recognition of agonist ligands by RXRs. | The nuclear receptor RXR is an obligate partner in many signal transduction pathways. We report the high-resolution structures of two complexes of the human RXRalpha ligand-binding domain specifically bound to two different and chemically unrelated agonist compounds: docosa hexaenoic acid, a natural derivative of eicos... |
11980704 | Crystal structure of murine sCEACAM1a[1,4]: a coronavirus receptor in the CEA family. | CEACAM1 is a member of the carcinoembryonic antigen (CEA) family. Isoforms of murine CEACAM1 serve as receptors for mouse hepatitis virus (MHV), a murine coronavirus. Here we report the crystal structure of soluble murine sCEACAM1a[1,4], which is composed of two Ig-like domains and has MHV neutralizing activity. Its N-... |
11978855 | Stress-induced deoxycorticosterone-derived neurosteroids modulate GABA(A) receptor function and seizure susceptibility. | Stress affects seizure susceptibility in animals and humans, but the underlying mechanisms are obscure. Here, we provide evidence that GABA(A) receptor-modulating neurosteroids derived from deoxycorticosterone (DOC) play a role in stress-related changes in seizure control. DOC, an adrenal steroid whose synthesis is enh... |
11978849 | Congenic mapping of alcohol and pentobarbital withdrawal liability loci to a <1 centimorgan interval of murine chromosome 4: identification of Mpdz as a candidate gene. | Risk for onset of alcoholism is related to genetic differences in acute alcohol withdrawal liability. We previously mapped a locus responsible for 26% of the genetic variance in acute alcohol withdrawal convulsion liability to a >35 centimorgan (cM) interval of murine chromosome 4. Here, we narrow the position of this ... |
11978818 | Isolation of a long-lasting eag-related gene-type K+ current in MMQ lactotrophs and its accommodating role during slow firing and prolactin release. | Native rat lactotrophs express thyrotrophin-releasing hormone-dependent K+ currents consisting of fast and slow deactivating components that are both sensitive to the class III anti-arrhythmic drugs that block the eag-related gene (ERG) K+ current (I(ERG)). Here we describe in MMQ prolactin-releasing pituitary cells th... |
11978812 | Phosphatidylinositol 3-kinase is required for the expression but not for the induction or the maintenance of long-term potentiation in the hippocampal CA1 region. | Several signal transduction pathways have been implicated in the induction of long-term potentiation (LTP), yet the signal transduction mechanisms behind the maintenance-expression phase of LTP are still poorly understood. We investigated the role of phosphatidylinositol 3-kinase (PI3-kinase) in LTP at Schaffer collate... |
11978132 | Mixed-metal supramolecular complexes coupling phosphine-containing Ru(II) light absorbers to a reactive Pt(II) through polyazine bridging ligands. | Supramolecular bimetallic Ru(II)/Pt(II) complexes [(tpy)Ru(PEt(2)Ph)(BL)PtCl(2)](2+) and their synthons [(tpy)Ru(L)(BL)](n)()(+) (where L = Cl(-), CH(3)CN, or PEt(2)Ph; tpy = 2,2':6',2''-terpyridine; and BL = 2,2'-bipyrimidine (bpm) or 2,3-bis(2-pyridyl)pyrazine (dpp)) have been synthesized and studied by cyclic voltam... |
11978126 | Solution and solid state studies of a triangle-square equilibrium: anion-induced selective crystallization in supramolecular self-assembly. | We report that an equilibrium mixture of triangular and square supramolecular species results when the flexible, ditopic donor unit, trans-bis(4-pyridyl)ethylene, is reacted with the ditopic acceptor unit, cis-(Me(3)P)(2)Pt(OTf)(2), in a one-to-one ratio. Both products are characterized in solution, by way of multinucl... |
11978109 | In(2)(OH)(3)(BDC)(1.5) (BDC = 1,4-benzendicarboxylate): an In(III) supramolecular 3D framework with catalytic activity. | The new hybrid inorganic-organic polymer In(2)(OH)(3)[O(4)C(8)H(4)](1.5) has been hydrothermally obtained. Conditions for the synthesis are reported. The crystal structure of this material has been established by single-crystal X-ray diffraction: it is monoclinic, with space group P2(1)/c (Nomicron. 14), a = 6.772(1) A... |
11978097 | Dinuclear rhodium and iridium complexes with mixed amido/methoxo and amido/hydroxo bridges. | The reactions of [[M(mu-OMe)(cod)](2)] (M = Rh, Ir; cod = 1,5- cyclooctadiene) with p-tolylamine, alpha-naphthylamine, and p-nitroaniline gave complexes with mixed-bridging ligands, [[M(cod)](2)(mu-NHAr)(mu-OMe)]. Similarly, the related complexes [[Rh(cod)](2)(mu-NHAr)(mu-OH)] were prepared from the reactions of [[Rh(m... |
11978192 | Interaction of multidrug resistance reversal agents with P-glycoprotein ATPase activity on blood-brain barrier. | <h4>Aim</h4>To gain further insights into the mechanism of the ATP-dependent interaction of P-glycoprotein (P-gp) with various multidrug resistance (MDR) reversal agents.<h4>Methods</h4>Bovine brain capillary endothelial cells (BCEC) were isolated from cerebral gray matter using modifications of the mechanical homogeni... |
11975627 | Rigid tetranitroresorcinarenes. | [reaction: see text]. o-alkylation of C2V-symmetrical resorcinarene tetraesters 2 with 2 equiv of 1,3-difluoro-4,6-dinitrobenzene readily affords conformationally rigid octanitro resorcinarene 3, which is a potential scaffold for the design of supramolecular structures. |
11975621 | Regioselective O-substitution of p-tert-butylcalix[7]arene. | [structure: see text]. The first examples of selectively functionalized calix[7]arenes have been obtained by weak-base promoted O-alkylation or O-benzoylation of p-tert-butylcalix[7]arene. Mono-, 1,3- and 1,4-disubstituted calix[7]arenes have been obtained in workable yields, while the 1,2,4,6-tetrasubstitution was ach... |
11975599 | Control of enantioselectivity in the photochemical conversion of alpha-oxoamides into beta-lactam derivatives. | [reaction: see text]. Several approaches to asymmetric induction in the alpha-oxoamide (1) to beta-lactam (2) photorearrangement are described. Best results are obtained via irradiation of ionic and covalent chiral auxiliary-containing reactants in the crystalline state and in the interior supercages of zeolites. |
11975586 | Application of ruthenium-induced macrocyclization for the construction of macrocyclic depsipeptides. | The synthesis of a biaryl ether containing macrocyclic depsipeptide 1 was achieved in 6% overall yield. The desired macrocycle was constructed by cyclization of a phenol into eta(6)-ruthenium complex. The ruthenium metal was subsequently photolytically deprotected to obtain the macrocycle 1. |
11975578 | Acid-catalyzed formation of hexahomooxacalix[3]arenes. | The role of acid catalysis in oxacalix[3]arene synthesis has been investigated. A range of acids were used to optimize the yield of tert-butyloxacalix[3]arene, the most efficient being p-toluenesulfonic acid, which, with local symmetry complementary with that of the lower rim of the calixarene, provides a templating ef... |
11975564 | Synthesis of diazadibenzoperylenes and characterization of their structural, optical, redox, and coordination properties. | Tetraphenoxy-substituted diazadibenzoperylenes 5a,b were synthesized from tetrachloroperylene tetracarboxylic acid bisanhydride 1 through imidization with benzylamine, nucleophilic displacement of the four chlorine atoms by phenolates, carbonyl group reduction by LiAlH(4)/AlCl(3), and subsequent Pd/C-promoted debenzyla... |
11975551 | Host-guest interactions between beta-cyclodextrin and the (Z)-phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole: the first kinetic study of a ring-ring interconversion in a "confined environment". | The effect of beta-cyclodextrin (beta-CD) on the mononuclear heterocyclic rearrangement of the (Z)-phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole (1) in aqueous borate buffer at pH = 9.6 has been analyzed at temperatures ranging from 293.15 to 313.15 K. The trend of the absorption spectra of 1 as a function of ... |
11976300 | Caulobacter crescentus synthesizes an S-layer-editing metalloprotease possessing a domain sharing sequence similarity with its paracrystalline S-layer protein. | Strains of Caulobacter crescentus elaborate an S-layer, a two-dimensional protein latticework which covers the cell surface. The S-layer protein (RsaA) is secreted by a type I mechanism (relying on a C-terminal signal) and is unusual among type I secreted proteins because high levels of protein are produced continuousl... |
11976288 | Functional characterization and regulation of gadX, a gene encoding an AraC/XylS-like transcriptional activator of the Escherichia coli glutamic acid decarboxylase system. | The Escherichia coli chromosome contains two distantly located genes, gadA and gadB, which encode biochemically undistinguishable isoforms of glutamic acid decarboxylase (Gad). The Gad reaction contributes to pH homeostasis by consuming intracellular H(+) and producing gamma-aminobutyric acid. This compound is exported... |
11976266 | The role of spinal neuropeptides and prostaglandins in opioid physical dependence. | This study examined the role of spinal calcitonin gene-related peptide (CGRP), substance P, and prostaglandins in the development and expression of opioid physical dependence. Administration of escalating doses (5 - 100 mg kg-1, i.p.) of morphine for 7 days markedly elevated CGRP and substance P- immunoreactivity in th... |
11976264 | Regulation of human penile smooth muscle tone by prostanoid receptors. | We have characterized the prostanoid receptors involved in the regulation of human penile arterial and trabecular smooth muscle tone. Arachidonic acid induced relaxation of human corpus cavernosum strips (HCCS) that was blocked by the cyclo-oxygenase inhibitor, indomethacin, and augmented by the thromboxane receptor (T... |
11973348 | Clik1: a novel kinase targeted to actin stress fibers by the CLP-36 PDZ-LIM protein. | In this report we have characterized a novel, ubiquitously expressed kinase, Clik1, that is predominantly nuclear and undergoes autophosphorylation. Yeast two-hybrid analysis indicated a highly specific association between Clik1 and CLP-36, which was identified in 36 out of 37 Clik1-interacting clones. CLP-36 is a PDZ-... |
11971678 | Induction of murine AIDS virus-related sequences after burn injury. | To better understand the molecular signaling events leading to systemic inflammatory response syndrome (SIRS) and multiple organ failure (MOF), changes in gene expression profiles after burn injury were investigated by differential display. C57BLKS/J mice were subjected to 18% total body surface area (TBSA) full-thickn... |
11971726 | Synthesis of trithiolanes and tetrathianes from thiiranes catalyzed by ruthenium salen nitrosyl complexes. | The compound [Ru(salen)(NO)(H(2)O)](SbF(6)) (1) (salen = N,N'-ethylene-bis-salicylidene aminate) reacts catalytically with thiiranes and converts them to olefins and 1,2,3,4-tetrathianes or 1,2,3-trithiolanes. The monosubstituted thiiranes styrene sulfide and propylene sulfide reacted to form the corresponding olefin a... |
11971714 | Cooperative self-assembly of dendrimers via pseudorotaxane formation from a homotritopic guest molecule and complementary monotopic host dendrons. | Interaction of the homotritopic guest 1,3,5-tris[p-(benzylammoniomethyl)phenyl]benzene tris(hexafluorophosphate) (1a) with dibenzo-24-crown-8 (DB24C8) leads to the sequential self-assembly of [2]-, [3]-, and [4]-pseudorotaxanes 7a, 8a, and 9a, respectively. The self-assembly processes were studied using NMR spectroscop... |
11971713 | Remarkable structures of cyclotri(deoxycholate) and cyclotetra(24-norcholate) acetate esters. | X-ray crystallographic determinations and AM1 calculations have defined the solid-state and gas-phase structures of cyclotri(deoxycholate) and cyclotetra(24-norcholate). The latter cyclotetramer is one of the largest open macrocycles ever subjected to crystallography. |
11971698 | 19F, (1)H-HOESY and PGSE NMR studies of neutral trinuclear complexes of Au(I) and Hg(II): evidence for acid-base stacking in solution. | By combining the information from 19F, 1H-HOESY and PGSE NMR methodologies, unprecedented direct evidence has been obtained for the formation of supramolecular assemblies in solution between the trinuclear cyclic AuI basic compounds ([Au(mu-C2,N3-bzim)]3 (bzim = 1-benzylimidazolate), 1, and [Au(mu-C,N-C(OEt)=N-p-C6H4-C... |
11971696 | The first example of macrocycles containing butterfly transition metal cluster cores via novel tandem reactions. | A novel type of double butterfly, two mu-CO-containing dianions {[(mu-CO)Fe2(CO)6]2[mu-SCH2(CH2OCH2)nCH2S-mu]}2- (m1, n = 2, 3), has been synthesized from dithiol HSCH2(CH2OCH2)nCH2SH (n = 2, 3), Fe3(CO)12, and Et3N in THF at room temperature. While dianions m1 react in situ with CS2 followed by treatment with dihalide... |
11971690 | A chiral molecular square with metallo-corners for enantioselective sensing. | A family of chiral molecular squares based on fac-Re(CO)3Cl metallocorners and enantiopure atropisomeric bipyridine bridging ligands (L1-4) have been synthesized in high yields by refluxing ClRe(CO)5 and L1-4 in 1:1 molar ratio. These novel chiral metallocycles have been characterized by 1H and 13C{1H} NMR, UV-vis, lum... |
11971689 | A synthesis of (+)-FR182877, featuring tandem transannular Diels-Alder reactions inspired by a postulated biogenesis. | An efficient biomimetic synthesis of the reported structure of the hexacyclic, cytotoxic secondary metabolite FR182877 is described. The successful route features the synthesis of a 19-membered ring carbocycle using two pi-allyl palladium(II)-mediated C-C bond-forming reactions. This polyunsaturated macrocycle undergoe... |
11967380 | Subunit organization in cytoplasmic dynein subcomplexes. | Because cytoplasmic dynein plays numerous critical roles in eukaryotic cells, determining the subunit composition and the organization and functions of the subunits within dynein are important goals. This has been difficult partly because of accessory polypeptide heterogeneity of dynein populations. The motor domain co... |
11967373 | Structural changes and molecular interactions of hydrophobin SC3 in solution and on a hydrophobic surface. | The hydrophobin SC3 belongs to a class of small proteins functioning in the growth and development of fungi. Its unique amphipathic property and remarkable surface activity make it interesting not only for biological studies but also for medical and industrial applications. Biophysical studies have revealed that SC3 po... |
11967366 | Thermodynamic analysis of the binding of component enzymes in the assembly of the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus. | The peripheral subunit-binding domain (PSBD) of the dihydrolipoyl acetyltransferase (E2, EC 2.3.1.12) binds tightly but mutually exclusively to dihydrolipoyl dehydrogenase (E3, EC 1.8.1.4) and pyruvate decarboxylase (E1, EC 1.2.4.1) in the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus. Isoth... |
11967341 | The liver is a major organ for clearing simian immunodeficiency virus in rhesus monkeys. | Infection with human or simian immunodeficiency virus (SIV) is characterized by the rapid turnover of both viral particles and productively infected cells. It has recently been reported that the clearance of SIV in vivo is exceedingly fast, with half-lives on the order of minutes. The underlying mechanism or site respo... |
11967340 | Association of the caveola vesicular system with cellular entry by filoviruses. | The filoviruses Ebola Zaire virus and Marburg virus are believed to infect target cells through endocytic vesicles, but the details of this pathway are unknown. We used a pseudotyping strategy to investigate the cell biology of filovirus entry. We observed that specific inhibitors of the caveola system, including chole... |
11967329 | New World arenavirus clade C, but not clade A and B viruses, utilizes alpha-dystroglycan as its major receptor. | Alpha-dystroglycan (alpha-DG) has been identified as a major receptor for lymphocytic choriomeningitis virus (LCMV) and Lassa virus, two Old World arenaviruses. The situation with New World arenaviruses is less clear: previous studies demonstrated that Oliveros virus also exhibited high-affinity binding to alpha-DG but... |
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