A5086820473- Marine Sponges and Natural Products
- Metabolomics and Mass Spectrometry Studies
- Synthesis and Biological Evaluation
- Crystallography and molecular interactions
- X-ray Diffraction in Crystallography
- Natural product bioactivities and synthesis
- Bone Tissue Engineering Materials
- Synthesis and Biological Activity
- Microbial Natural Products and Biosynthesis
- Synthesis and Reactivity of Heterocycles
- Cancer, Hypoxia, and Metabolism
- Metal complexes synthesis and properties
- Crystallization and Solubility Studies
- Bioactive Compounds and Antitumor Agents
- Advanced NMR Techniques and Applications
- Nonlinear Optical Materials Research
- Click Chemistry and Applications
- Chemical Synthesis and Analysis
- Dental materials and restorations
- Thyroid Cancer Diagnosis and Treatment
- Phenothiazines and Benzothiazines Synthesis and Activities
- Ionic liquids properties and applications
- Nanocomposite Films for Food Packaging
- Inorganic and Organometallic Chemistry
- Pomegranate: compositions and health benefits
Universidade Federal do Rio de Janeiro
2000-2024
Centro Universitário da Cidade
2020
Universidade da Amazônia
2018
Universidade Estadual de Campinas (UNICAMP)
2000-2018
University of California, Riverside
2016
Fundação Oswaldo Cruz
2005-2011
Universidade de São Paulo
2000-2008
Universidade Federal de São Carlos
2000-2003
Universidade Federal do Paraná
2002
Pectin-high amylose starch mixtures (1:4; 1:1; 4:1) were cross-linked at different degrees and characterized by rheological, thermal, X-ray diffraction NMR analyses. For comparison, samples without cross-linker addition also prepared characterized. Although all behaved as gels, the results evidenced that phosphorylation reaction promotes network strengthening, resulting in covalent gels (highest critical stress, G' recovery %). Likewise, presented highest thermal stability. However, alkaline...
The effects of adding Nb 2 O 5 on the physical properties and glass structure two series derived from 45S5 Bioglass ® have been studied. multinuclear 29 Si, 31 P, 23 Na solid‐state MAS NMR spectra glasses, Raman spectroscopy determination some generated insight into glasses. Si suggest that 5+ ions create cross‐links between several oxygen sites, breaking – bonds to form a range polyhedra [Nb(OM) 6− y (OSi) ], where 1 ≤ M = Na, Ca, or P. show Nb–O–P would occur in terminal sites. Adding...
Cytological analysis of thyroid nodules detected using ultrasound-guided fine-needle aspiration technique is an efficient method for the diagnosis well-differenciated tumors such as papillary carcinoma. However, between 10 to 30% all nodules, cytological based on biopsies leads "indeterminated" identification. Consequently, a surgical excision then necessary definite histological lesions, resulting in 85% patient with indeterminated undergoing unnecessary surgery since their tumor finally...
This work deals with the spectroscopic (supported by quantum chemistry calculations), structural, and morphological characterization of mefenamic acid (2-[(2,3-(dimethylphenyl)amino] benzoic acid) polymorphs, known as forms I II. Polymorph was obtained recrystallization in ethanol, while form II reached heating up to 175 °C, promote solid phase transition. Experimental theoretical vibrational band assignments were performed considering presence centrosymmetric dimers. Besides shifts...
Fractionation of the crude methanol extract ascidian Cystodytes dellechiajei collected in Brazil yielded two novel alkaloids, sebastianine A (1) and B (2). The structures both 1 2 were established by analysis spectroscopic data, indicating an unprecedented ring system for compounds, comprising a pyridoacridine fused with pyrrole unit pyrrolidine condensed α-hydroxyisovaleric acid Both alkaloids displayed cytotoxic profile against panel HCT-116 colon carcinoma cells indicative p53 dependent mechanism.
The photodimerization of 9-tert-butyl-anthracene ester in molecular crystal nanorods can cause expansions up to 15%. This expansion results from the formation a metastable crystalline intermediate, solid-state reacted dimer (SSRD). In this paper, combination powder X-ray diffraction, nuclear magnetic resonance, and computational modeling is used determine structure SSRD intermediate. An ensemble six possible structures obtained, which differ only small packing details that lead different...
Crystals composed of photoreactive molecules represent a new class photomechanical materials with the potential to generate large forces on fast timescales. An example is photodimerization 9-tert-butyl-anthracene ester (9TBAE) in molecular crystal nanorods that leads an average elongation 8%. Previous work showed this expansion results from formation metastable crystalline product. In article, it shown how novel combination ensemble oriented-crystal solid-state NMR, X-ray diffraction, and...
Arenosclerins A (2), B (3), and C (4), as well haliclonacyclamine E (1), are new tetracyclic alkylpiperidine alkaloids isolated from a species of marine sponge belonging to the order Haplosclerida, Arenosclera brasiliensis, endemic southeastern Brazilian coast. The were their hydrochloride salts identified by analysis spectroscopic data. Data obtained (1)H-(1)H COSY, HMBC, HSQC-TOCSY NMR experiments allowed complete assignment (1)H (13)C resonances, NOESY ROESY spectra showed that only...
Two new bromotyrosine-derived alkaloids, caissarine A (1) and B (2), along with three known biogenetically related aeroplysinin-1, fistularin-3, the artifact of isolation 2-(3,5-dibromo-4-dimethoxy-1-hydroxy-2,5-cyclohexadien-1-yl)ethanamide, have been isolated from Aplysina caissara, an endemic species marine sponge Southeastern Brazilian coast. The alkaloids identified by analysis spectroscopic data. While has a 2-hydroxyagmatine moiety in its structure, caissarin is first naturally...
In this paper we present an analog of the Bell's inequalities violation test for $N$ qubits to be performed in a nuclear magnetic resonance (NMR) quantum computer. This can used simulate or predict results different tests, with distinct configurations and larger number qubits. To demonstrate our scheme, implemented simulation Clauser, Horne, Shimony Holt (CHSH) inequality using two qubit NMR system compared those photon experiment. The experimental are well described by Quantum Mechanics...
The synthesis and characterization of silica nanoparticles (NPs) covalently modified with an aminonaphthoquinone are reported. aminopropylsilicagelnaphthoquinone (APSGNQ) was obtained by nucleophilic substitution 2-methoxy-1,4-naphthoquinone aminopropylsilicalgel (APSG) NPs. Solid state 13C 29Si nuclear magnetic resonance spectra confirmed that the naphthoquinone is bonded to APSG. Due solubility APSGNQ in common organic solvents, solution ultraviolet-visible spectroscopy used determine...
Leishmaniasis is a highly prevalent, yet neglected disease caused by protozoan parasites of the genus Leishmania. In search for newer, safer, and more effective antileishmanial compounds, we herein present study mode action in addition to detailed structural biological characterization LQOF-G6 [N-benzoyl-N'-benzyl-N″-(4-tertbutylphenyl)guanidine]. X-ray crystallography extensive NMR experiments revealed that nearly exclusively adopts Z conformation stabilized an intramolecular hydrogen bond....
The role of sympathetic nerve activity in the changes arterial blood pressure and renal function caused by chronic administration NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor nitric oxide (NO) synthesis, was examined sham bilaterally denervated rats. Several studies have demonstrated that is elevated acutely after L-NAME administration. To evaluate L-NAME-induced hypertension, we compared response four groups (N = 10 each) male Wistar-Hannover rats weighing 200 to 250 g: 1)...
Abstract We have studied the molecular dynamics of one major macromolecules in articular cartilage, chondroitin sulfate. Applying 13 C high‐resolution magic‐angle spinning NMR techniques, signals all rigid cartilage can be suppressed, allowing exclusive detection highly mobile The technique is also used to detect sulfate artificial tissue‐engineered cartilage. material that based on matrix producing chondrocytes cultured a collagen gel should provide properties as close possible those...
Uncaria tomentosa (Willd.) DC. and U. guianensis (Aubl.) Gmel., known as cat's claw, are large woody vines native to the Amazonian Central American rainforests. The species contain, in different proportions, indole oxindole alkaloids, triterpenoid glycosides, sterols proanthocyanidins. can be chemically identified by its alkaloid profile content, whereas has no satisfactorily established chemical markers. This work describes, for first time, isolation of kaempferol-3,7-O-(α)-dirhamnoside...
Novel 2-(R-phenyl)amino-3-(2-methyl-propenyl)-[1,4]-naphthoquinones (R = H, 4-OMe, 4-Ferrocenyl, 4-Me, 3-Me, 4-I, 3-I, 4-CN, 3-CN, 4-NO2 and 3-NO2) derived from nor-lapachol [2-hydroxy-3-(2-methylpropenyl)-1,4-naphthoquinone] were obtained in good yields. Their structures proposed on the basis of a single crystal X-ray diffraction study OMe, 2b), ¹H 13C NMR studies calculations using B3LYP functional 6-311+G(2d,p) set. The half-wave potentials aminonaphthoquinones chemical shifts 3-propenyl...