Browsing CIQUS-Artigos by Issue Date
Now showing items 21-40 of 411
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Defining the Nature of Thermal Intermediate in 3 State Folding Proteins: Apoflavodoxin, a Study Case
(Plos, 2012)The early stages of the thermal unfolding of apoflavodoxin have been determined by using atomistic multi microsecondscale molecular dynamics (MD) simulations complemented with a variety of experimental techniques. Results ... -
Tandem Brønsted Acid Promoted and Nazarov Carbocyclizations of Enyneacetals to Hydroazulenones
(Wiley, 2012)A new and efficient metal-free entry to hydroazulenones is reported. Enyneacetals were easily converted into hydroazulene skeletons by tandem Brønsted-acidpromoted carbocyclizations followed by stereospecific Nazarov ... -
Synthesis of 3-alkyl enol mimics inhibitors of type II dehydroquinase: factors influencing their inhibition potency
(Royal Society of Chemistry, 2012-03-05)Several 3-alkylaryl mimics of the enol intermediate in the reaction catalyzed by type II dehydroquinase were synthesized to investigate the effect on the inhibition potency of replacing the oxygen atom in the side chain ... -
Peripheral Functionalization of Dendrimers Regulates Internalization and Intracellular Trafficking in Living Cells
(American Chemical Society, 2012-04-07)GATG (gallic acid-triethylene glycol) dendrimers represent appealing nanostructures for biomedical applications. The incorporation of specific ligands and targeting and imaging agents on their surface has resulted in ... -
Stereoselective Formation of Chiral Metallopeptides
(Wiley, 2012-05-03)Playing into our hands: The achiral bipyridine amino acid fluorenylmethyloxycarbonyl 5‐amino‐3‐oxapentanoic acid (Fmoc‐O1PenBpy‐OH) has been used for the solid‐phase synthesis of metallopeptides. Circular dichroism, molecular ... -
Exploring the efficiency of gallic acid-based dendrimers and their block copolymers with PEG as gene carriers
(Future Science, 2012-07-20)The synthesis of a new family of amino-functionalized gallic acid-triethylene glycol (GATG) dendrimers and their block copolymers with polyethylene glycol (PEG) has recently being disclosed. In addition, these dendrimers ... -
Dendrimers reduce toxicity of Aβ 1-28 peptide during aggregation and accelerate fibril formation
(Elsevier, 2012-11)The influence of a GATG (gallic acid-triethylene glycol) dendrimer decorated with 27 terminal morpholine groups ([G3]-Mor) on the aggregation process of Alzheimer's peptide has been investigated. Amyloid fibrils were formed ... -
The rainbow instanton method: A new approach to tunneling splitting in polyatomics
(AIP Publishing, 2012-12-11)A new instanton approach is reported to tunneling at zero-temperature in multidimensional (MD) systems in which a “light particle” is transferred between two equivalent “heavy” sites. The method is based on two concepts. ... -
Stepwise Filtering of the Internal Layers of Dendrimers by Transverse-Relaxation-Edited NMR
(American Chemical Society, 2013)The characteristic distribution of transverse relaxation times (T2) within dendrimers (shorter values at the core than the periphery) can be exploited in T2-edited 1D and 2D NMR experiments for the stepwise filtering of ... -
Disclosing an NMR-Invisible Fraction in Chitosan and PEGylated Copolymers and Its Role on the Determination of Degrees of Substitution
(American Chemical Society, 2013)An unexpected 1H NMR invisible fraction (IF) for chitosan (CS) and CS-g-PEG is reported. The presence of this IF is remarkable considering that solution NMR is recognized as the method of choice for studying structural ... -
Real-Time Evaluation of Binding Mechanisms in Multivalent Interactions: A Surface Plasmon Resonance Kinetic Approach
(American Chemical Society, 2013)Multivalency is a key, ubiquitous phenomenon in nature characterized by a complex combination of binding mechanisms, with special relevance in carbohydrate–lectin recognition. Herein we introduce an original surface plasmon ... -
The Dynamics of Dendrimers by NMR Relaxation: Interpretation Pitfalls
(American Chemical Society, 2013)NMR is a powerful tool to study the dynamics of dendrimers. By analogy to linear polymers, shorter T1 relaxation times have been traditionally associated to less mobile nuclei and hence, dendrimers described with reduced ... -
Photoinduced Proton and Charge Transfer in 2‑(2′- Hydroxyphenyl)imidazo[4,5‑b]pyridine
(American Chemical Society, 2013)This paper deals with the interplay between solvent properties and isomerism of 2-(2′-hydroxyphenyl)imidazo[4,5-b]pyridine (1), and the proton and charge-transfer processes that the different isomers undergo in the ... -
Low-temperature spin excitations in frustrated ZnCr2O4 probed by high-field thermal conductivity
(APS Physics, 2013)The magnetoelastic excitations of spin frustrated ZnCr2O4 are studied by the magnetic field dependence of the thermal conductivity k down to 50 mK. Above the first-order magnetostructural transition at TN,S≈ 12.5 K, spin ... -
Dissociation of a Strong Acid in Neat Solvents: Diffusion Is Observed after Reversible Proton Ejection Inside the Solvent Shell
(American Chemical Society, 2013)Strong-acid dissociation was studied in alcohols. Optical excitation of the cationic photoacid N-methyl-6-hydroxyquinolinium triggers proton transfer to the solvent, which was probed by spectral reconstruction of picosecond ... -
Sequence‐Selective DNA Recognition with Peptide–Bisbenzamidine Conjugates
(Wiley, 2013)Transcription factors (TFs) are specialized proteins that play a key role in the regulation of genetic expression. Their mechanism of action involves the interaction with specific DNA sequences, which usually takes place ... -
Rhodium(III)-catalyzed intramolecular annulations involving amide-directed C–H activations: synthetic scope and mechanistic studies
(Royal Society of Chemistry, 2013)Alkyne tethered benzamides undergo rhodium(III)-catalyzed intramolecular annulations to give tricyclic isoquinoline derivatives in good yields. DFT calculations suggest that the reaction mechanism involves a migratory ... -
Gold(I)‐Catalyzed Cascade Cycloadditions between Allenamides and Carbonyl‐Tethered Alkenes: An Enantioselective Approach to Oxa‐Bridged Medium‐Sized Carbocycles
(Wiley, 2013)Gold standard: Allenamides react with aldehydes or ketones having γ, δ, or ε alkenyl groups, upon activation with suitable gold catalysts, to provide oxa-bridged systems containing seven- to nine-membered carbocycles, in ... -
Mycobacterium tuberculosis Shikimate Kinase Inhibitors: Design and Simulation Studies of the Catalytic Turnover
(American Chemical Society, 2013)Shikimate kinase (SK) is an essential enzyme in several pathogenic bacteria and does not have any counterpart in human cells, thus making it an attractive target for the development of new antibiotics. The key interactions ... -
Mechanistic Basis of the Inhibition of Type II Dehydroquinase by (2S)- and (2R)-2-Benzyl-3-dehydroquinic Acids
(American Chemical Society, 2013)The structural changes caused by the substitution of the aromatic moiety in (2S)-2-benzyl-3-dehydroquinic acids and its epimers in C2 by electron-withdrawing or electron-donating groups in type II dehydroquinase enzyme ...