The liquid product of the pyrolysis of biomass is a mixture of an organic phase and other aqueous, being the last one rich in phenol monomers which can be used in industrial chemistry as input for plastic and resin production. This work aimed to develop a method for extracting phenols present in the aqueous fraction obtained from the pyrolysis of guava seeds, using ultrasonic assisted liquid-liquid extraction (UALLE) with ethyl acetate and ionic liquids (ILs) as co-solvents (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl) amide (BMIM.NTF2) and 1-butyl-3-methylimidazolinium hexafluorophosphate (BMIM.PF6)). The percentage IL, ultrasonic bath potency, temperature, and pH were studied. Quantification of twelve phenol monomers was performed using gas chromatography-mass spectrometry (GC-MS) and the total phenol concentration (TPC) was performed using UV-Vis spectrophotometer. The ionic liquid BMIM.NTF2 was more efficient for phenol extraction than BMIM.PF6. The phenolic extractions were influenced by the pH of the aqueous fraction (higher extraction yields at pH ≤ 7), and thus, presented recoveries above 80% for both ionic liquids.

Simple synthetic procedures have been applied to obtain luminescent carbon quantum dots, also referred as C-dots, from an abundant carbon source, that is, from the brewing industry waste. The synthetic procedures have been conducted aiming to investigate the effects of the oxidation stage on the properties of the nanomaterial. C-dots down- and up-conversion properties, as well as their potential for cellular imaging experiments in live (and adhered) cells, are disclosed herein.

Um líquido iônico imidazólio de função específica derivado do ácido kójico natural teve suas interações supramoleculares investigadas no estado sólido, em solução e em fase gasosa. Diferentes técnicas como difração de raios X de monocristal, espectroscopia de ressonância magnética nuclear (NMR), espectrofotometria UV-Vis, medidas de condutividade, espalhamento de raios X em baixo ângulo (SAXS), espectrometria de massas (tandem) com ionização por electrospray (ESI-MS(/MS)) e cálculos teóricos permitiram uma investigação estrutural aprofundada desse líquido iônico de função específica e suas interações supramoleculares.

An imidazolium-based task-specific ionic liquid derived from the natural kojic acid had its supramolecular interactions investigated in solid, solution and gas phase. The use of a set of techniques formed by single-crystal X-ray diffraction, nuclear magnetic resonance (NMR) spectroscopy, UV-Vis spectrophotometry, conductivity measurements, small angle X-ray scattering (SAXS), electrospray (tandem) mass spectrometry (ESI-MS(/MS)), and theoretical calculations allowed a deep investigation of the structural organization of the task-specific ionic liquid and its supramolecular interactions.

The bioactive 3,4-dihydropyrimidin-2(1H)-thione derivative known as Monastrol was synthesized under catalyzed and non-catalyzed conditions through the Biginelli multicomponent reaction under solvent-free conditions. The use of two Lewis acids (FeCl3 and CuCl2) and two Brønsted acids (HCl and CF3COOH) as catalysts improved the reaction yields of the transformation compared with the non-catalyzed reaction. The experiments investigated catalysis and its role, the importance of multicomponent reactions and their green features, and the application of these concepts to the synthesis of a biologically important structure.

Algumas das nossas contribuições para o desenvolvimento da área da catálise em líquidos iônicos são descritas. Além disto, o uso de ligantes ionofílicos bem como a utilização de catalisadores com "etiquetas iônicas" são apresentados e discutidos. Devido à importância dos líquidos iônicos, as suas propriedades fisicoquímicas de interesse bem como a sua organização supramolecular são temas discutidos.

Some of our contributions to the development of catalysis in ionic liquids are described. Also, the use of ionophilic ligands and catalysts with ionic tags are presented and discussed. Due to the importance of ionic liquids, some physicochemical properties of interest and their supramolecular organization are described.

Novos sensores planejados fluorescentes derivados do núcleo 2,1,3-benzotiadiazola foram sintetizados, caracterizados e aplicados como marcadores celulares de imageamento em vivo onde se observou exclusivamente preferência por mitocôndrias em modelos celulares de câncer de mama (MCF-7). A eficiência destes novos marcadores se mostrou muito superior ao corante comercial MitoTracker® Red. Experimentos celulares e in vitro permitiram uma compreensão mais profunda da relação existente entre a arquitetura molecular planejada dos novos corantes e a seletividade celular observada

Novel designed 2,1,3-benzothiadiazole fluorescent probes were synthesized, characterized and applied as live cell fluorescence imaging probe staining only mitochondria in mammalian cancer cell lines (MCF-7). The efficiency of these new probes was found to be much superior to that of the commercially available MitoTracker® Red. Cellular and in vitro experiments allowed better understanding of the relationship between the planned molecular architecture of the new dyes and the observed cellular selectivity.

A modificação experimental para a síntese do MESG (2-amino-6-mercapto-7-metilpurina ribonucleosídeo) 1 foi realizada com sucesso e sua caracterização total apresentada. ESI(+)-MSMS em alta resolução foram realizados indicando que a clivagem nucleosídica como principal e um possível mecanismo S N1. Cálculos ab initio baseados em estados de transição blueprint corroboram com a proposta de um mecanismo S N1 e descartam a possibilidade de um mecanismo S N2. Ensaios com a enzima purina nucleosídica fosforilase (PNP, tanto humana como de M. tuberculosis) indicam a eficiência do substrato na reação de fosforilação do MESG e permitem a determinação de fosfato inorgânico em tempo real em ensaios biológicos.

A modified experimental procedure for the synthesis of MESG (2-amino-6-mercapto-7-methylpurine ribonucleoside) 1 has been successfully performed and its full characterization is presented. High resolution ESI(+)-MSMS indicates both the nucleoside bond cleavage as the main fragmentation in the gas phase and a possible S N1 mechanism. Ab initio transition state calculations based on the blue print transition state support this mechanistic rationale and discard an alternative S N2 mechanism. Assays using purine nucleoside phosphorylase (PNP) enzyme (human and M. tuberculosis sources) indicate its efficiency in the phosphorolysis of MESG and allow the quantitative determination of inorganic phosphate in real time assay.