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11781478 | A structural hierarchy in the hydrogen-bonded adduct N,N'-dimethylpiperazine-tartaric acid-water (1/2/2): an N-component N-dimensional structure (N =3) with substructures having N = 1 and 2. | In the hydrated adduct N,N'-dimethylpiperazine-1,4-diium bis(3-carboxy-2,3-dihydroxypropanoate) dihydrate, [MeNH(CH2CH2)2NHMe]2+*2(C4H5O6)-*2H2O or C6H16N2(2+)*2C4H5O6-*2H2O, formed between racemic tartaric acid and N,N'-dimethylpiperazine (triclinic P-1, Z' = 0.5), the cations lie across centres of inversion. The anio... |
11781461 | Tetrakis[phthalocyaninato(2-)antimony(III)] hexadecaiodotetraantimony(III). | Crystals of a new antimony(III) phthalocyanine complex with the formula [Sb(C32H16N8)]4(Sb4I16), or (SbPc)4+*[Sb(4)I(16)]4-, where Pc is phthalocyaninate, have been obtained by the reaction of pure powdered antimony with phthalonitrile under a stream of iodine vapour. The crystals are built up from separate but interac... |
11781457 | Mu1,3-azido-diazidotetrakis(1,10-phenanthroline)dicopper(II) azide tetrahydrate. | In the title compound, [Cu2(mu-(1,3)-N3)(N3)2(phen)4](N3)*4H2O (phen is 1,10-phenanthroline, C12H8N2), each of the two Cu atoms is surrounded by two N atoms of two azide anions and by four N atoms of two 1,10-phenanthroline ligands [Cu-N distances are 1.964 (3), 2.009 (3), 2.018 (3), 2.054 (3), 2.306 (3) and 2.759 (4) ... |
11742082 | Building highly sensitive dye assemblies for biosensing from molecular building blocks. | Fluorescence superquenching is investigated for polyelectrolytes consisting of cyanine dye pendant polylysines ranging in number of polymer repeat units (N(PRU)) from 1 to 900, both in solution and after adsorption onto silica nanoparticles. As N(PRU) increases, the absorption and fluorescence evolve from monomer spect... |
11935193 | Effects of randomly methylated-beta-cyclodextrins (RAMEB) on the bioavailability and aerobic biodegradation of polychlorinated biphenyls in three pristine soils spiked with a transformer oil. | The low bioavailability of polychlorinated biphenyls (PCBs) in soils often results in their slow and partial aerobic biodegradation. The process can be enhanced by supplementing soils with cyclodextrins. However, pure cyclodextrins are expensive and we have therefore explored the use of a less costly technical grade mi... |
11733522 | Mapping of functional domains in the p22(phox) subunit of flavocytochrome b(559) participating in the assembly of the NADPH oxidase complex by "peptide walking". | The superoxide-generating NADPH oxidase complex of phagocytes consists of a membranal heterodimeric flavocytochrome (cytochrome b(559)), composed of gp91(phox) and p22(phox) subunits, and four cytosolic proteins, p47(phox), p67(phox), p40(phox), and the small GTPase Rac (1 or 2). All redox stations involved in electron... |
23686931 | A dendritic antenna for near-infrared emission of Nd3+ ions. | An interior of 18 amide groups and a periphery functionalized with 24 dansyl groups forms a light-harvesting dendrimer which features intense absorption bands in the near-UV spectral region and a strong fluorescence band in the visible region. Upon encapsulation of Nd(3+) ions, the fluorescence of the dansyl groups is ... |
23686924 | Tunable surface-enhanced Raman scattering from large gold nanoparticle arrays. | Raman signal enhancements in excess of 10(7) can be achieved at near-infrared wavelengths when mid-nanometer sized gold particles self-organize into close-packed planar arrays. These substrates generate stable surface-enhanced Raman scattering which changes dramatically as a function of periodic structure and excitatio... |
19265880 | Identification of Seed Gall Nematodes of Agronomic and Regulatory Concern with PCR-RFLP of ITS1. | A molecular analysis of eight described species of seed gall nematode, along with six undescribed isolates from different hosts, has revealed a strong association between nucleotide sequence polymorphism and host status. Each anguinid nematode associated with a unique host produced a unique PCR-RFLP pattern for the ITS... |
18968448 | Immobilization of oligonucleotides on crosslinked poly(vinyl alcohol) for application in DNA chips. | In biotechnological applications there is an enormeous growth in the development of new miniaturized devices to reduce timescales, cost and amounts of reagents and starting materials. DNA chips represent miniaturized analytical tools that allow the simultaneous detection of different targets for high throughput screeni... |
18968438 | Interaction between organophosphorous hydrolase and paraoxon studied by surface chemistry in situ at air-water interface. | Subphase conditions have been optimized to obtain stable organophosphorous hydrolase (OPH-EC 3.1.8.1) as Langmuir films. The Langmuir film was characterized by surface pressure and surface potential-area isotherms and UV-Vis spectroscopy in situ. The interaction of an organophosphorous compound, namely Paraoxon, with t... |
18498483 | New combined treatment of hypermelanosis: analytical studies on efficacy and stability improvement. | The aim of this work was to evaluate the synergy between different lightening agents when associated; depigmenting activity was tested in vitro by monitoring the appearance of dopachrome, an intermediate in the melanogenesis process. The results obtained were compared with the depigmenting activity of each single compo... |
12404418 | Self-Complementary Quadruple Hydrogen-Bonding Motifs as a Functional Principle: From Dimeric Supramolecules to Supramolecular Polymers. | The self-association of individual molecules can lead to the formation of highly complex and fascinating supramolecular aggregates. However, for binding motifs which rely only on hydrogen bonds, a combination of several such weak interactions is necessary to observe self-association in solution. Systems based on four h... |
12404417 | Organic Nanoparticles in the Aqueous Phase-Theory, Experiment, and Use. | Many active organic compounds and organic effect materials are poorly soluble in water, or even insoluble. Aqueous forms of application thus require special formulation techniques to utilize or optimize the physiological (pharmaceuticals, cosmetics, plant protection, nutrition) or technical (varnishes, printing inks, t... |
12240028 | Inducing structural polarity using fluorinated organics: X-ray crystal structures of p-XC6F4CN (X = Cl, Br, I). | Non-centrosymmetric structures are promoted through the use of perfluoroaromatics containing structure-directing CN...X (X = Br, I) supramolecular synthons. |
12240021 | Protein-calixarene interactions: complexation of Bovine Serum Albumin by sulfonatocalix[n]arenes. | The complexation of Bovine Serum Albumin with sulfonatocalix[n]arenes has been demonstrated by means of electrospray mass spectrometry, dynamic light scattering and atomic force microscopy; with sulfonatocalix[4]arene one strong and two weaker binding sites are detected; the effects on the structure of thin films forme... |
12240018 | Silver(I) carboxylates: versatile inorganic analogs of carboxylic acids for supramolecular network formation. | Dimeric motifs formed by silver(I) carboxylates, illustrated here by the unit Ag2(CF3CO2)2, resemble the well known dimerization of carboxylic acids, i.e. 'H2(RCO2)2', but exhibit greater flexibility, while permitting further elaboration into neutral coordination networks through linkage of the silver centres via ditop... |
12239997 | Reversible encapsulation of multiple, neutral guests in hexameric resorcinarene hosts. | A variety of aromatic guest molecules are co-encapsulated with Bu4SbBr in an assembly of six resorcinarene subunits. |
12005424 | Evaluation of the conformational propensities of peptide isosteres as a basis for selecting bioactive pseudopeptides. | Our aim was to compare the repertoires of conformers formed by the model zwitterionic peptides AA and AAA in aqueous solution with the conformational profiles of a range of their peptide isosteres, so as to facilitate selection of isosteres for synthesis and testing as biologically stable surrogates of bioactive di- an... |
11859924 | Roles of BCL-2 and caspase 3 in the adenosine A3 receptor-induced apoptosis. | Selective A3 adenosine receptor agonists have been shown to induce apoptosis in a variety of cell types. In this study we examined the effects of adenosine receptor agonists selective for A1, A2A, or A3 receptors on the induction of apoptosis in primary cultures of rat astrocytes and in C6 glial cells. Treatment of the... |
11844867 | Ab initio studies of the reaction of hydrogen transfer from DNA to the calicheamicinone diradical. | <h4>Background</h4>The biological activity of enediyne chemotherapeutic (anti-cancer) agents is attributed to their ability to cleave duplex DNA. Part of the reaction of cleavage is the abstraction of hydrogens from the deoxyribose moiety of DNA by the biradical formed via a Bergman rearrangement.<h4>Methods</h4>The me... |
11824603 | Comparative studies of various run buffers for chiral capillary electrophoresis using chiral crown ether as a chiral selector. | In the capillary electrophoretic separation of primary amine enantiomers using (+)-(18-crown-6)-tetracarboxylic acid (18C6H4) as a chiral selector, the presence of run buffer constituents such as tris(hydroxymethyl)aminomethane (Tris) or Na+ competing with analytes for 18C6H4, diminishes the effectiveness of 18C6H4. In... |
11822438 | Synthesis, spectroscopic, and structural properties of spirocyclopropanated bicyclobutylidenes and their radical cations. | The spirocyclopropanated bicyclobutylidenes 3-7 have been prepared by McMurry coupling of the corresponding spirocyclopropanated cyclobutanone (3 and 5), Staudinger-Pfenniger reaction (4), oxidative coupling of a Wittig ylide (4) or Wittig olefination of perspirocyclopropanated cyclobutanone (6 and 7). The structure of... |
11822426 | High-Relaxivity contrast agents for magnetic resonance imaging based on multisite interactions between a beta-cyclodextrin oligomer and suitably functionalized GdIII chelates. | The results reported in this work show that tightly assembled adducts formed by trisubstituted GdIII complexes and a beta-CD multimer (Poly-beta-CD, d.p. ca. 12) may represent very interesting candidates for novel MRI applications wherein a high number of paramagnetic ions endowed with high relaxivity (per GdIII ion) a... |
11822425 | Metallo-Supramolecular initiators for the preparation of novel functional architectures. | Polymeric materials containing coordinative units have become a field of increasing interest. The combination of inorganic metal-containing units and macromolecules leads to supramolecular structures with new properties. One promising approach to such systems is the application of metallo-supramolecular initiators for ... |
11814186 | Cationic diazacrown ethers as selectors for the separation of inorganic anions by capillary electrophoresis. | Two types of positively charged diazacrown ether derivatives involving two quaternary ammonium ions in the 12- and 18-membered rings have been investigated as selectors for the separation of inorganic anions by capillary electrophoresis. Both the cationic macrocycles largely affected the electrophoretic mobilities of a... |
11814057 | Microtubule dynamics. | Microtubules are fibrous elements in the cytoplasm of eukaryotic cells, where they perform a wide variety of functions. Microtubules are major organizers of the cell interior and are vitally involved in motility events such as chromosome migration during cell division. To fulfill their physiological function, microtubu... |
11814052 | Mechanisms of self-incompatibility in flowering plants. | Self-incompatibility is a widespread mechanism in flowering plants that prevents inbreeding and promotes outcrossing. The self-incompatibility response is genetically controlled by one or more multi-allelic loci, and relies on a series of complex cellular interactions between the self-incompatible pollen and pistil. Al... |
11812837 | Flavones inhibit the hexameric replicative helicase RepA. | Helicases couple the hydrolysis of nucleoside triphosphates (NTPs) to the unwinding of double-stranded nucleic acids and are essential in DNA metabolism. Thus far, no inhibitors are known for helicases except heliquinomycin isolated from Streptomyces sp. As the three-dimensional structure of the hexameric replicative D... |
11812827 | The protein ORF80 from the acidophilic and thermophilic archaeon Sulfolobus islandicus binds highly site-specifically to double-stranded DNA and represents a novel type of basic leucine zipper protein. | The cryptic high copy number plasmid pRN1 from the thermophilic and acidophilic crenarchaeote Sulfolobus islandicus shares three conserved open reading frames with other S.islandicus plasmids. One of the open reading frames, namely orf80, encodes a 9.5 kDa protein that has no homology to any characterised protein. Reco... |
11812826 | A mutation in the primer grip region of HIV-1 reverse transcriptase that confers reduced fidelity of DNA synthesis. | A compensatory mutation (M230I) in the primer grip of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) restores the replication capacity of virus having a Y115W mutation in their RT coding region. The Y115W substitution impairs DNA polymerase activity and produces an enzyme with a lower fidelity o... |
11812264 | BindingDB: a web-accessible molecular recognition database. | This paper presents an initial description of the BindingDB, a public web-accessible database of measured binding affinities for various molecular types (http://www.bindingdb.org). The BindingDB allows queries based upon a range of criteria, including chemical similarity or substructure, sequence homology, numerical cr... |
11812257 | Molecular recognition by beta-cyclodextrin derivatives: FEP vs MM/PBSA study. | The complexation of p-tert-butylphenyl p-tert-butylbenzoate, N-(p-tert-butylphenyl)-p-tert-butylbenzamide and a bisadamantyl-phosphate derivative with a beta-cyclodextrin derivative formed by two cyclodextrin units linked by a disulfide bridge on one of the C6 atoms have been studied by computational methods (free ener... |
11809931 | Metal binding affinity and structural properties of an isolated EF-loop in a scaffold protein. | To establish an approach to obtain the site-specific calcium binding affinity of EF-hand proteins, we have successfully designed a series of model proteins, each containing the EF-hand calcium-binding loop 3 of calmodulin, but with increasing numbers of Gly residues linking the loop to domain 1 of CD2. Structural analy... |
11804735 | Topographical characterization and surface force spectroscopy of the photochemical lignin model compound. | By combining the results from atomic force microscopy (AFM) and environmental scanning electron microscopy (ESEM), herein we investigate properties of photochemical lignin model compounds. We provide evidence that photochemical lignin forms random, probably non-functional structures. The topography of such structures i... |
11803399 | Complement activation by recombinant adenoviruses. | Recombinant adenoviruses are currently the most important vector system in gene therapy. Adenoviruses frequently cause upper respiratory tract infections in humans and anti-adenoviral antibodies are found in 35-70% of the population. Therefore in the majority of potential patients receiving adenoviral gene therapy, the... |
11802661 | Intranasal administration of midazolam in a cyclodextrin based formulation: bioavailability and clinical evaluation in humans. | Intranasal administration of midazolam has been of particular interest because of the rapid and reliable onset of action, predictable effects, and avoidance of injections. The available intravenous formulation (Dormicum i.v. solution from Hoffmann-La Roche) is however less than optimal for intranasal administration due... |
11788058 | Application of beta-galactosidase enzyme complementation technology as a high throughput screening format for antagonists of the epidermal growth factor receptor. | We have applied enzyme complementation technology to develop a screen for antagonists of the epidermal growth factor (EGF) receptor. Chimeric proteins containing two weakly complementing deletion mutants of Escherichia coli beta-galactosidase (beta-gal), each fused to the EGF receptor extracellular and transmembrane do... |
11789876 | Study on the supramolecular system of meso-tetrakis (4-sulfonatophenyl) porphyrin and cyclodextrins by spectroscopy. | The ability of beta-cyclodextrin (beta-CD), sulfurbutylether-beta-CD (SBE-beta-CD) and hydroxypropyl-beta-CD (HP-beta-CD) to break the aggregate of the meso-Tetrakis (4-sulfonatophenyl) porphyrin (TPPS4) and to form 2:1 inclusion complexes has been studied by adsorption and fluorescence spectroscopy. The formation cons... |
11786227 | Exploring computational lead optimisation with affinity constants obtained by surface plasmon resonance for the interaction of PorA epitope peptides with antibody against Neisseria meningitidis. | LUDI is a program used for de novo structure-based design of ligands and can predict binding of ligands quantitatively using a scoring function. Here we evaluate LUDI in a lead optimisation study with ligands for the antibody MN12H2, that has been raised against outer membrane protein PorA epitope P1.16 of Neisseria me... |
11784189 | Highly selective synthesis of heterosubstituted aromatic sulfamides. | The sulfamide functional group is increasingly relevant in both medicinal and supramolecular chemistry, yet few selective synthetic steps are available for its elaboration. We report here a mild, general, and efficient method for the selective differentiation of N-atom substituents of aromatic sulfamides. [reaction: se... |
11783941 | The nature of the delocalized cations in azulenic bacteriorhodopsin analogs. | Depending on the size and shape of their azulenic chromophores, azulenic bacteriorhodopsin (bR) pigment analogs can exist as either an initial pigment P1, a more red-shifted final pigment P2 or an equilibrium mixture of both. The absorption spectra of red-shifted bR analogs exhibit characteristic narrow-band shapes sim... |
11780641 | Concurrent molecular recognition of the amino acid and tRNA by a ribozyme. | We have recently reported an in vitro-evolved precursor tRNA (pre-tRNA) that is able to catalyze aminoacylation on its own 3'-hydroxyl group. This catalytic pre-tRNA is susceptible to RNase P RNA, generating the 5'-leader ribozyme and mature tRNA. The 5'-leader ribozyme is also capable of aminoacylating the tRNA in tra... |
11775695 | Reversible fixation of carbon dioxide at nickel(0) centers: a route for large organometallic rings, dimers, and tetramers. | The reaction between bis(cycloocta-1,5-diene)nickel(0), carbon dioxide and benzaldehyde-N-furfurylideneimine (A) in 1,4-dioxane or THF results in the formation of the 24-membered organometallic macrocycles of the type [(A)Ni(-CH(R1)-N(R2)-COO-)]6(solv)n (R1: phenyl, R2: furfurylidene, solv: 1,4-dioxane in 1a, THF in 1b... |
11775688 | Nanotube formation by hydrophobic dipeptides. | A wide range of applications has been suggested for peptide-based nanotubes, which first attracted considerable interest as model systems for membrane channels and pores. The intriguing and unprecedented observation of nanotube formation by supramolecular self-assembly of the four dipeptides L-Leu-L-Leu, L-Leu-L-Phe, L... |
11775677 | Host-guest interaction of 12-MC-4, 15-MC-5, and fused 12-MC-4 metallacrowns with mononuclear and binuclear carboxylato complexes: structure and magnetic behavior. | Interaction of manganese with salicylhydroxamic ligands leads to the formation of the 12-membered metallacrown [Mn(II)(2(2,4-DP)2(HCOO)2]-[12-MC(Mn(III)N(shi)-4](py)6 (2) (H-2,4-DP =2-(2,4-dichlorophenoxy)propionic acid) and the 15-membered metallacrown [Mn(II)(2,4-D)2][15-MC(Mn(III)N(shi)-5](py)6 (1) (H-2,4-D = 2,4-di... |
11775177 | Effect of cyclodextrins on surface and pore properties of soil clay minerals. | Although cyclodextrins are increasingly used in soil decontamination, little is known about their effects on soil physicochemical properties. In this work, the surface and pore properties of randomly methylated beta-cyclodextrin (RAMEB) and three typical clay minerals were characterized, and the effects of RAMEB concen... |
11774916 | Spectroscopic investigations of poly(propyleneimine)dendrimers using the solvatochromic probe phenol blue and comparisons to poly(amidoamine) dendrimers. | The physical and chemical properties of PPI dendrimers' interior were investigated using the fluorescent, solvatochromic probe phenol blue. In aqueous solutions of each generation studied, two discrete dye populations were clearly observed. PPI dendrimers were shown to form a tight, nonpolar association with the vast m... |
11755400 | 'Morphs' (MRFs): metal-reversible folding domains for differential IgG binding. | <h4>Background</h4>Selective recognition and binding of IgG molecules is the basis for a host of immunological and affinity purification techniques. Capture of an IgG in these procedures relies chiefly on its interaction with one of a variety of reengineered bacterial receptors which bind to the Fc region of IgG molecu... |
11755398 | Chain initiation on the soraphen-producing modular polyketide synthase from Sorangium cellulosum. | <h4>Background</h4>Polyketides are structurally diverse natural products with a wide range of useful activities. Bacterial modular polyketide synthases (PKSs) catalyse the production of non-aromatic polyketides using a different set of enzymes for each successive cycle of chain extension. The choice of starter unit is ... |
11755209 | Pharmacological in vitro evaluation of new substance P-cyclodextrin derivatives designed to drug targeting towards NK1-receptor bearing cells. | Some biological properties of new bifunctional conjugates designed for drug targeting were evaluated through in vitro experiments. Eight peptidylcyclodextrin compounds were used, which correspond to modified beta- or gamma-cyclodextrin (CD) grafted on neuropeptide substance P (SP) or a shorter derivative (SP(4-11)). Us... |
11754292 | Construction of a square-planar molecular box: self-assembly of palladium(II) complexes of 3,6,9,16,19,22-hexaazatricyclo[22.2.2.2(11,14)]triacon-11,13,24,26(1),27,29-hexaene through hydrogen-bonding interactions. | Binuclear palladium(II) complexes of the macrocyclic polyamine 3,6,9,16,19,22-hexaazatricyclo[22.2.2.2(11,14)]triacon-11,13,24,26(1),2 7,29-hexaene (L) are used to construct molecules having special shapes. In this study two binuclear palladium(II) complexes [Pd(2)LI(2)]I(2)and [Pd(2)LCl(2)](NO(3))(2).H(2)O are synthes... |
11754270 | A new polytopic bis-diazacrown-ether-polypyridine ligand and its complexes with Zn(II) salts and mononuclear and dendritic Ru(II) precursors. Synthesis, absorption spectra, redox behavior, and luminescence properties. | The new polytopic receptor 1 containing two terpyridine, one phenanthroline, and two diazacrown-ether sites has been prepared using a modular approach. Such a new species contains several pieces of information in its structure which can be processed by different metal ions to give different supramolecular inorganic arc... |
11754269 | Palladium (II) complexes of oxybenziporphyrin. | 8,19-Dimethyl-9,13,14,18-tetraethyloxybenziporphyrin coordinates palladium(II) to form the four-coordinate anionic complex [(OBP)Pd(II)](-). The NMR data provide evidence for the retention of macrocyclic aromaticity and coordination via a carbon sigma-donor. Protonation of the external oxygen atom to give [(HOBP)Pd(II)... |
11752467 | Neisseria gonorrhoeae PilV, a type IV pilus-associated protein essential to human epithelial cell adherence. | Type IV pili (Tfp) of Neisseria gonorrhoeae, the Gram-negative etiologic agent of gonorrhea, facilitate colonization of the human host. Tfp are assumed to play a key role in the initial adherence to human epithelial cells by virtue of the associated adhesin protein PilC. To examine the structural and functional basis f... |
11752443 | The V122I cardiomyopathy variant of transthyretin increases the velocity of rate-limiting tetramer dissociation, resulting in accelerated amyloidosis. | The transthyretin (TTR) amyloid diseases are of keen interest, because there are >80 mutations that cause, and a few mutations that suppress, disease. The V122I variant is the most common amyloidogenic mutation worldwide, producing familial amyloidotic cardiomyopathy primarily in individuals of African descent. The sub... |
11752428 | Crystal structure of the macrocycle-forming thioesterase domain of the erythromycin polyketide synthase: versatility from a unique substrate channel. | As the first structural elucidation of a modular polyketide synthase (PKS) domain, the crystal structure of the macrocycle-forming thioesterase (TE) domain from the 6-deoxyerythronolide B synthase (DEBS) was solved by a combination of multiple isomorphous replacement and multiwavelength anomalous dispersion and refined... |
11749541 | Pulse radiolysis studies of dendritic macromolecules with biphenyl peripheral groups and a ruthenium tris-bipyridine core. | Electron-transfer reactions in Fréchet-type dendrimers with biphenyl peripheral groups and a ruthenium core were investigated by pulse radiolysis techniques. Fast electron-transfer rates found in the two ruthenium dendrimers suggest a very efficient electronic coupling between the peripheral donor groups and the core a... |
11741431 | Cooperativity in drug-DNA recognition: a molecular dynamics study. | NMR studies have shown that the minor groove-binding ligand Hoechst 33258 binds to the two T4/A4 tracts within the duplex d(CTTTTCGAAAAG)2 in a highly cooperative manner, such that in titration experiments no intermediate 1:1 complex can be detected. The NMR-derived structures of the free DNA and the 2:1 complex have b... |
11741428 | Molecular-based electronically switchable tunnel junction devices. | Solid-state tunnel junction devices were fabricated from Langmuir Blodgett molecular monolayers of a bistable [2]catenane, a bistable [2]pseudorotaxane, and a single-station [2]rotaxane. All devices exhibited a (noncapacitive) hysteretic current-voltage response that switched the device between high- and low-conductivi... |
11741412 | Spirodienone route for the stereoselective methylene functionalization of p-tert-butylcalix[4]arene. | A new method for the regio- and stereoselective functionalization of two distal methylene groups of p-tert-butylcalixarene (1a) is described. Reaction of the meso bis(spirodienone) calixarene derivative 2a with bromine afforded the tetrabrominated product 3a derived from exo 1,4-additions of bromine to the diene subuni... |
11741411 | Cyclodextrin dimers as cleavable carriers of photodynamic sensitizers. | Several phthalocyanines carrying hydrophobic components have been synthesized and shown to bind to a group of cyclodextrin dimers with a carbon-carbon double bond in the linker. The complexes are soluble in water. On irradiation in the presence of oxygen, the singlet oxygen produced cleaves the olefinic linkers in the ... |
11741580 | A critical appraisal of the mitochondrial coenzyme Q pool. | The function of the coenzyme Q (CoQ) pool in the inner mitochondrial membrane is reviewed in view of recent findings suggesting a supramolecular organization of the mitochondrial respiratory complexes. In spite of the structural evidence for preferential aggregations of the inner membrane components, most kinetic evide... |
11767092 | Effects of counter cations of base catalysts on nitrosation mechanisms. | Reaction of 2-butanone (1) with tert-butyl nitrite (tert-BuONO) was performed using base catalysts (RO-M+: R=CH3, C2H5; M+=Li+, Na+, K+) in alcohols (CH3OH or C2H5OH). In this report, the effects of M+ of RO-M+ on the nitrosation mechanisms were investigated. The yield of E-hydroxyimino compound (5E) increases much bet... |
11748143 | FGF-induced lens cell proliferation and differentiation is dependent on MAPK (ERK1/2) signalling. | Members of the fibroblast growth factor (FGF) family induce lens epithelial cells to undergo cell division and differentiate into fibres; a low dose of FGF can stimulate cell proliferation (but not fibre differentiation), whereas higher doses of FGF are required to induce fibre differentiation. To determine if these ce... |
11747320 | Activation and activities of the p53 tumour suppressor protein. | The p53 tumour suppressor protein inhibits malignant progression by mediating cell cycle arrest, apoptosis or repair following cellular stress. One of the major regulators of p53 function is the MDM2 protein, and multiple forms of cellular stress activate p53 by inhibiting the MDM2-mediated degradation of p53. Mutation... |
11747419 | Structure and dynamics of hydrated statherin on hydroxyapatite as determined by solid-state NMR. | Proteins directly control the nucleation and growth of biominerals, but the details of molecular recognition at the protein-biomineral interface remain poorly understood. The elucidation of recognition mechanisms at this interface may provide design principles for advanced materials development in medical and ceramic c... |
11747418 | Poly(p-phenyleneethynylene)s by alkyne metathesis. | Alkyne metathesis was effected by mixtures of Mo(CO)(6) and phenols at elevated temperatures based on an improved version of the method reported by Mortreux and Mori. When propynylated arenes are subjected to these reaction conditions, the formation of diarylalkynes is often quantitative and likewise allows the synthes... |
11747417 | Sapphyrins: versatile anion binding agents. | Sapphyrin was the first expanded porphyrin to be reported in the literature and remains among the most extensively studied. Much of the interest in this macrocycle reflects its ability to bind anions, a phenomenon that has been examined in solution and in the solid state by a wide range of experimental techniques. In t... |
11746693 | Hierarchy of simulation models in predicting molecular recognition mechanisms from the binding energy landscapes: structural analysis of the peptide complexes with SH2 domains. | Computer simulations using the simplified energy function and simulated tempering dynamics have accurately determined the native structure of the pYVPML, SVLpYTAVQPNE, and SPGEpYVNIEF peptides in the complexes with SH2 domains. Structural and equilibrium aspects of the peptide binding with SH2 domains have been studied... |
11746584 | Pharmacokinetics and enhancement patterns of macromolecular MR contrast agents with various sizes of polyamidoamine dendrimer cores. | Four macromolecular contrast agents are synthesized to visualize small vessels by MRI using generation-3 (G3D), -4 (G4D), -5 (G5D), and -6 (G6D) polyamidoamine dendrimers conjugated to chelated gadolinium (Gd). The pharmacokinetics, enhancement patterns, and the ability of these constructs to visualize fine vessels is ... |
11745769 | Prednisolone-appended alpha-cyclodextrin: alleviation of systemic adverse effect of prednisolone after intracolonic administration in 2,4,6-trinitrobenzenesulfonic acid-induced colitis rats. | The titled compound is a cyclodextrin derivative in which prednisolone 21-succinate (PDsuc) is covalently bound to one of the secondary hydroxyl groups of alpha-cyclodextrin (alpha-CyD) via an ester linkage. In this study, the PDsuc-appended alpha-CyD ester conjugate (PDsuc/alpha-CyD conjugate) was intracolonically adm... |
11746462 | Ultrastructural study of the precursor to fungiform papillae prior to the arrival of sensory nerves in the fetal rat. | The structure of precursors to fungiform papillae without taste buds, prior to the arrival of sensory nerve fibers at the papillae, was examined in the fetal rat on embryonic day 13 (E13) and 16 (E16) by light and transmission electron microscopy in an attempt to clarify the mechanism of morphogenesis of these papillae... |
11747027 | Micro-MR angiography of normal and intratumoral vessels in mice using dedicated intravascular MR contrast agents with high generation of polyamidoamine dendrimer core: reference to pharmacokinetic properties of dendrimer-based MR contrast agents. | Pharmacokinetic characteristics of intravascular macromolecular magnetic resonance imaging (MRI) contrast agents with polyamidoamine dendrimer cores smaller than generation-7 were previously studied in the literature. To evaluate the effects of greater hepatic uptake on the pharmacokinetics of the larger generation den... |
11743786 | Synthesis and analysis of thio-, thiono-, and dithio-derivatives of whiskey lactone. | Cis- and trans-3-methyl-4-octanolide (1, whiskey lactones) were converted into their thio- (2), thiono- (3), and dithio- (4) derivatives by reaction with phosphorus pentasulfide. The reaction products were characterized by GC-mass spectrometry, (1)H NMR spectroscopy, and GC-olfactometry. Two-dimensional NOESY spectra s... |
11743785 | Competitive binding of aroma compounds by beta-cyclodextrin. | Retention of six aroma compounds has been studied after dehydration of ternary mixtures of aroma water and beta-cyclodextrin. A maximal retention of a mole of aroma per mole of beta-cyclodextrin has been observed for five of the aroma compounds, whereas retention of benzyl alcohol can be twice as high. Retention of a m... |
11743742 | Quantitative distinctions of active site molecular recognition by P-glycoprotein and cytochrome P450 3A4. | The bulk of characterized xenobiotic defense and disposition is conferred by the abundant enzymes cytochrome P450 3A4 and P-glycoprotein. Although expressed in many tissues, these enzymes are most abundant in the liver and intestine and seem to share most substrates and inhibitors, with the apparent synergy between the... |
11744197 | Electrochemistry and spectroscopy study on the interaction of microperoxidase-11 with lipid membrane. | The interaction of microperoxidase-11 (MP11) with cationic lipid vesicles of didodecyldimethylammonium bromide (DDAB) induces an alpha-helical conformation from random coil conformations in solution and this change then makes heme macrocycle more distorted. DDAB-induced MP11 conformations were investigated by cyclic vo... |
11765082 | New reversed-phase liquid chromatographic method to detect aflatoxins in food and feed with cyclodextrins as fluorescence enhancers added to the eluent. | The effect of succynil-beta-cyclodextrin (beta-CD-Su), dimethyl-beta-cyclodextrin (DIMEB) and beta-cyclodextrin (beta-CD) on the fluorescence of aflatoxins B1, B2, G1, G2 and M1 (AFB1, AFB2, AFG1, AFG2 and AFM1) was studied: beta-CD-Su promoted the largest fluorescence enhancement for AFB1 and AFM1 while DIMEB showed b... |
11743008 | Origin pairing ('handcuffing') as a mode of negative control of P1 plasmid copy number. | In one family of bacterial plasmids, multiple initiator binding sites, called iterons, are used for initiation of plasmid replication as well as for the control of plasmid copy number. Iterons can also pair in vitro via the bound initiators. This pairing, called handcuffing, has been suggested to cause steric hindrance... |
11742999 | Translocation portals for the substrates and products of a viral transcription complex: the bluetongue virus core. | The bluetongue virus core is a molecular machine that simultaneously and repeatedly transcribes mRNA from 10 segments of viral double-stranded RNA, packaged in a liquid crystalline array. To determine how the logistical problems of transcription within a sealed shell are solved, core crystals were soaked with various l... |
11742991 | Flipping a genetic switch by subunit exchange. | The bacteriophage T4 AsiA protein is a multifunctional protein that simultaneously acts as both a repressor and activator of gene expression during the phage life cycle. These dual roles with opposing transcriptional consequences are achieved by modification of the host RNA polymerase in which AsiA binds to conserved r... |
11742932 | Predictive value of microalbuminuria in medical ICU patients: results of a pilot study. | <h4>Study objectives</h4>To evaluate the predictive value of microalbuminuria in the development of acute respiratory failure (ARF) and multiple organ failure (MOF) in ICU patients.<h4>Design</h4>Prospective, observational study.<h4>Setting</h4>A 31-bed, mixed medicosurgical ICU in a university hospital.<h4>Patients</h... |
11738044 | The structure of the feruloyl esterase module of xylanase 10B from Clostridium thermocellum provides insights into substrate recognition. | <h4>Background</h4>Degradation of the plant cell wall requires the synergistic action of a consortium of predominantly modular enzymes. In Clostridiae, these biocatalysts are organized into a supramolecular assembly termed a "cellulosome." This multienzyme complex possesses, in addition to its well-described cellulolyt... |
11762559 | Pharmacokinetics of intravenous itraconazole followed by itraconazole oral solution in patients with human immunodeficiency virus infection. | This randomized, open-label, comparative study assessed the pharmacokinetics and safety of intravenous and oral hydroxypropyl-beta-cyclodextrin (HP-beta-CD) solutions of itraconazole in patients with advanced human immunodeficiency virus (HIV) infection. All patients received 1-hour intravenous infusions of itraconazol... |
11735589 | A rapid access to biaryl ether containing macrocycles by pairwise use of Ugi 4CR and intramolecular S(N)Ar-based cycloetherification. | [reaction: see text] From readily accessible starting materials, macrocycles with an endo aryl-aryl ether bond are synthesized in only two operations by combination of the Ugi four-component reaction and an intramolecular S(N)Ar reaction. The nitro group serves as an activator for the macrocyclization and provides a ha... |
11735586 | Visual recognition of triamines by phenolphthalein derivatives: consideration of the structure of the colored complex. | [structure: see text] A hybrid molecule 1 consisting of phenolphthalein and two crown ether moieties can be used to discriminate the length of linear triamines strictly by color development. The purple color is developed most deeply at -10 degrees C and fades with either an increase or decrease in temperature. |
11735577 | Synthesis and ring-expanding oligomerization of an extremely strained macrocyclic aromatic ether-sulfone. | [reaction: see text] An extremely strained, 5-ring, macrocyclic aromatic ether-sulfone, [-1,4-C(6)H(4)SO(2)-1,4-C(6)H(4)O-1,3-C(6)H(4)O-1,4-C(6)H(4)SO(2)-1,4-C(6)H(4)-], synthesized by nickel-catalyzed intramolecular coupling of a bis-chlorophenylene-terminated precursor, undergoes fluoride-promoted ring expansion in d... |
11735574 | Trehalose-based octopus glycosides for the synthesis of carbohydrate-centered PAMAM dendrimers and thiourea-bridged glycoclusters. | [structure: see text] The nonreducing disaccharide trehalose was modified into an octa-amino-functionalized core molecule to serve in the synthesis of carbohydrate-centered PAMAM glycodendrimers and thiourea-bridged glycoclusters. |
11735569 | Cooperative and selective lithium complexation of 2,11,13,22-tetraaza-5,8,16,19- tetraoxa-1,12-dioxocyclodocosanes. | [reaction: see text] Ureyleno crown ethers 2 and 3 bind with 2 equiv of Li(+) cooperatively and selectively over other alkali metal ions such as Na(+), K(+), and Cs(+). The binding constant for 3 was found to be 3.0 x 10(7) (L/mol)(2). |
11739789 | A novel karyoskeletal protein: characterization of protein NO145, the major component of nucleolar cortical skeleton in Xenopus oocytes. | The nucleolus is a ubiquitous, mostly spheroidal nuclear structure of all protein-synthesizing cells, with a well-defined functional compartmentalization. Although a number of nonribosomal proteins involved in ribosome formation have been identified, the elements responsible for the shape and internal architecture of n... |
11739787 | Microtubule-dependent organization of vaccinia virus core-derived early mRNAs into distinct cytoplasmic structures. | Vaccinia virus (vv) early transcription can be reconstituted in vitro from purified virions; in this assay mRNAs are made inside the viral core and subsequently extruded. Although the in vitro process has been extensively characterized, relatively little is known about vv early transcription in vivo. In the present stu... |
11740262 | Granulocyte colony-stimulating factor (G-CSF) stiffens leukocytes but attenuates inflammatory response without lung injury in septic patients. | <h4>Objective</h4>To determine whether granulocyte colony-stimulating factor (G-CSF) administration changes leukocyte deformability resulting in lung injury in patients with sepsis.<h4>Methods</h4>Twenty-five consecutive septic patients were divided randomly into two groups. Twelve patients were given recombinant human... |
11740254 | Mesenteric lymph is responsible for post-hemorrhagic shock systemic neutrophil priming. | <h4>Background</h4>Hemorrhagic shock-induced splanchnic hypoperfusion has been implicated as a priming event in the two event model of multiple organ failure (MOF). We have previously shown that early postinjury neutrophil (PMN) priming identifies the injured patient at risk for MOF. Recent in vitro studies have demons... |
11735293 | The molecular roots of compositional inheritance. | Non-covalent compositional assemblies, made of monomeric mutually catalytic molecules, constitute an alternative to alphabet-based informational biopolymers as a mechanism of primordial inheritance. Such assemblies appear implicitly in many "Metabolism First" origin of life scenarios, and more explicitly in the Graded ... |
11735533 | Bridged bis(beta-cyclodextrin)s possessing coordinated metal center(s) and their inclusion complexation behavior with model substrates: enhanced molecular binding ability by multiple recognition. | To investigate quantitatively the cooperative binding ability of several beta-cyclodextrin oligomers bearing single or multiligated metal center(s), the inclusion complexation behavior of four bis(beta-cyclodextrin)s (2-5) linked by 2,2'-bipyridine-4,4'-dicarboxy tethers and their copper(II) complexes (6-9) with repres... |
11735508 | Synthesis of cyclodextrin-based carbohydrate clusters by photoaddition reactions. | The syntheses of homogeneous cyclodextrin-based carbohydrate clusters, persubstituted with beta-D-thioglucosyl or D-thiolactosyl residues on either (a) the primary face, (b) the secondary face, or (c) both the primary and the secondary faces of their cyclodextrin tori, are described. The key step in the synthetic metho... |
11735507 | Anion allosteric effect in the recognition of tetramethylammonium salts by calix[4]arene cone conformers. | Rigid calix[4]arene cone conformers, which are efficient receptors for quaternary ammonium salts, are usually obtained through the functionalization of their lower rim with suitable groups. Using flexible cone conformer of calix[4]arene, bearing four 4-hydroxybenzyl groups as cooperative and rigidifying structural elem... |
11735506 | Nanostructures via noncovalent synthesis: 144 hydrogen bonds bring together 27 components. | This paper describes the spontaneous and reversible assembly of approximately 20 kDa synthetic hydrogen-bonded assemblies via the formation of 144 cooperative hydrogen bonds. These nanostructures ( approximately 3.0 x 5.5 nm), consisting of 27 different components, have been carefully characterized using a combination ... |
11739586 | The permissive cue laminin is essential for growth cone turning in vivo. | The proper guidance of migrating growth cones relies on the balance of multiple guidance cues in the embryonic environment. In addition to guidance cues, growth cones are in contact with other substrates that may contribute to the pathfinding of neurons. For example, in the developing insect peripheral nervous system, ... |
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