A5014400551- Asymmetric Synthesis and Catalysis
- Supramolecular Self-Assembly in Materials
- Synthetic Organic Chemistry Methods
- Chemical Synthesis and Reactions
- Chemical Synthesis and Analysis
- Porphyrin and Phthalocyanine Chemistry
- Molecular spectroscopy and chirality
- Lipid Membrane Structure and Behavior
- Inorganic and Organometallic Chemistry
- Chemical synthesis and alkaloids
- Carbohydrate Chemistry and Synthesis
- Analytical Chemistry and Chromatography
- Photochromic and Fluorescence Chemistry
- Advanced Synthetic Organic Chemistry
- Organoboron and organosilicon chemistry
- Enzyme Catalysis and Immobilization
- Photodynamic Therapy Research Studies
- Fluorine in Organic Chemistry
- Asymmetric Hydrogenation and Catalysis
- Nanocluster Synthesis and Applications
- Hydrogels: synthesis, properties, applications
- Organic and Inorganic Chemical Reactions
- Plant Toxicity and Pharmacological Properties
- Polydiacetylene-based materials and applications
- Ferrocene Chemistry and Applications
Universidade Federal de São Paulo
2007-2024
Instituto de Ciências Farmacêuticas
2016-2021
Diversité, adaptation et développement des plantes
2019-2021
Fundação de Apoio à Universidade Federal de São Paulo
2008
Universidade Estadual de Campinas (UNICAMP)
2005-2008
Universidade Federal Fluminense
2008
Scripps Research Institute
2005
Universidade de São Paulo
2001-2005
Abstract Self‐assembled structures obtained from organic molecules have shown great potential for applications in a wide range of domains. In this context, short peptides prove to be particularly versatile class building blocks self‐assembled materials. These species afford the biocompatibility and polymorphic richness typical proteins while allowing synthetic availability robustness smaller molecules. At nano‐to‐mesoscale, architectures peptide units exhibit stability large variety...
A comprehensive study of the self-assembly in water a lipopeptide consisting sequence l-proline, l-arginine and l-tryptophan with hydrocarbon chain has been performed. Fluorescence assays were used to determine critical aggregation concentration. In situ small-angle X-ray scattering (SAXS) molecular dynamics simulations showed presence spherical micelles diameters around 6 nm. agreement these results, cryo-TEM images globular aggregates ranging from ≈4 nm up ≈9 Furthermore, catalytic...
Morphological, spectroscopic, and scattering studies of the self-assembly aggregation mixtures [RF]4 P[RF]4 peptides (where R = arginine; F phenylalanine; P proline), in solution as hydrogels, were performed to obtain information about polymorphism. CD data confirmed a β-sheet secondary structure aqueous solution, TEM images revealed nanofibers with diameters ∼10 nm micrometer lengths. SAXS curves fitted using mass fractal-component long cylinder shell form factor for liquid samples, only...
The self-assembly and biocatalytic activity of the proline-functionalized lipopeptide PRW-NH-C16 are examined compared to that related PRW–O-C16 lipopeptide, which differs in having an ester linker between lipid chain tripeptide headgroup instead amide linker. Lipopeptide self-assembles into spherical micelles above a critical aggregation concentration, similar behavior reported previously [B. M. Soares et al. Phys. Chem. Phys., 2017, 19, 1181—1189]. However, shows improved catalytic model...
Different polymorphic forms of peptide assemblies influence the stereoselectivity aldol reactions in water medium.
The self-assembly of the amphiphilic lipopeptide PAEPKI-C16 (P = proline, A alanine, E glutamic acid, K lysine, I isoleucine, and C16 hexadecyl) was investigated using a combination microscopy, spectroscopy, scattering methods compared to that C16-IKPEAP with same (reversed) peptide sequence alkyl chain positioned at N-terminus lacking free N-terminal proline residue. catalytic activity these peptides then model aldol reaction system. For PAEPKI-C16, cryo-TEM images showed formation...
Good levels of substrate-controlled, 1,5-syn-stereoinduction are obtained in boron-mediated aldol reactions β-trichloromethyl-β-alkoxy and β-trifluoromethyl-β-alkoxy methylketones with achiral aldehydes, independent the nature β-alkoxy protecting group (TBS or PMB). In case boron β-aryl-β-alkoxy methylketones, 1,5-anti-adducts were high diastereoselectivity only a β-OPMB group.
We wish to describe here that good levels of substrate-based, 1,5-syn-stereocontrol could be achieved in the boron-mediated aldol reactions beta-trichloromethyl methylketones with achiral aldehydes, independent nature beta-alkoxy protecting group.
EFFICIENT METHODS.The indan ring system is present in several compounds with important pharmacological properties.In this account recent examples of selected methods (Friedel-Crafts acylation, cycloaddition reactions, contraction, cyclization and resolution) for the synthesis indans are discussed.
We have examined the double-diastereodifferentiating aldol addition reactions of chiral enolborinate 1a with aldehydes leading to corresponding adducts excellent levels 1,5-anti diastereoselection.
Attempts to apply the 1H NMR ABX method for assignment of stereochemistry β-hydroxy ketones aldols 4−10 deriving from α-methyl aldehydes lacking β-branches reveals that presence a β-branch in aldehyde reaction partner is necessary so average chemical environment Ha and Hb different Felkin anti-Felkin (see conformational pairs A/B C/D, respectively). When chiral lacks β-branch, as case precursors 4−10, energies E F (for ketone derivatives), conformers G H aldols, are too close energy (within...
6-Methoxy-1-tetralone was transformed in six steps into an indan derivative related to the sesquiterpenes mutisianthol and jungianol. Key involve a thallium(III)-promoted ring-contraction (to assemble unit) Wittig olefination attach side chain).
The oxidation of a series 1,2-dihydronaphthalenes substituted in the aromatic ring was investigated with thallium trinitrate (TTN) methanol or trimethylorthoformate (TMOF) as solvent. In all cases, indans are produced, although yield varied from excellent to poor, depending on structure substrate. presence an electron-donating group substrate favors rearrangement, whereas significant amounts glycolic derivatives, well naphthalenes, were obtained bearing electron-withdrawing groups, such Br...
ASYMMETRIC INDUCTION IN THE BORON-MEDIATED ALDOL REACTIONS OF β-OXYGENATED METHYL KETONES.High levels of substrate-based 1,5-stereoinduction are obtained in the boron-mediated aldol reactions β-oxygenated methyl ketones with achiral and chiral aldehydes.Remote induction from boron enolates gives 1,5-anti adducts, enolate π-facial selectivity critically dependent upon nature β-alkoxy protecting group.This methodology has been strategically employed total synthesis several natural products.At...
The self-assembly of model [P]RWG lipopeptides (P: <sc>l</sc>-proline, R: <sc>l</sc>-arginine, W: <sc>l</sc>-tryptophan, G: <sc>l</sc>-glycine), containing one or two aliphatic octadecyl (C<sub>18</sub>) chains in water and cyclohexanone/water solutions was examined. enantiomeric selectivity found to be related the assembly catalyst molecules.
Proline, along with its derivatives, has been employed as an efficient organocatalyst for aldol reactions, the ability to promote creation of stereoselective C-C bonds. Even though Houk-List transition state model is able explain stereoselectivity observed when proline used a catalyst, few studies investigate role microheterogeneous media in modulating reaction outcome. In this work, molecular dynamics and electronic structure calculations were condensed phase. Our research focused on...
Front Cover: In article number 1900085 by Wendel A. Alves and co-workers, the self-assembly properties of peptide nanomaterials in relation to their design composition are surveyed. It is emphasized how environmental conditions can influence morphology nanostructures, this dependence be suitably exploited for stimuli-responsive systems.
The reaction of a series 1-tetralones with thallium trinitrate supported on Montmorillonite K-10 clay led to products ring contraction (methyl indan-1-carboxylates) and/or alpha-oxidation (2-methoxy-1-tetralones), in variable yields.
Abstract We investigated the effect of gold nanoparticles (AuNPs) on aggregation a CFF (C=cysteine; F=phenylalanine) tripeptide (derived from A β peptide) in aqueous medium. Special attention was dedicated to role AuNPs as inducers and inhibitors during nucleation kinetics structure resulting scaffolds carefully investigated. At millimolar concentrations, found form ‐sheet structures organized into long filaments. Spectral signatures topography filaments were studied by Raman spectroscopy...
Guanidiniocarbonyl pyrrole (GCP) conjugated lipopeptides improve aldol reaction catalysis by enhanced the molecules packing parameter, as shown SAXS data and molecular dynamics simulations.