Resumo: A grand challenge in the field of heterogeneous catalysis is to identify and fully characterize sites that are competent for catalysis of desired chemical transformations, ideally with high selectivity, high activity, and high stability. We have found that automated AIM (ALD-like chemistry in MOFs, where ALD is atomic layer deposition) can be used for chemically clean vapor-phase installation of uniform arrays of identically structured, few-atom catalysts on the reactive nodes of suitably chosen metal-organic framework (MOF) materials. This methodology, along with a solution-phase analogue termed SIM, can yield metal-oxygen, metal-sulfur, or metal(0) clusters of a predetermined size, shape, and chemical composition.

This talk will sketch the approach to synthesis and characterization of MOF-supported arrays of well-defined clusters, and then illustrate, via one or two brief case studies, their application as catalysts for desirable, but challenging gas- and condensed-phase chemical transformations. Together with input from computational modeling, these kinds of experiments can be used to address fundamental questions in contemporary Catalysis Science that require atomically precise knowledge of the siting and composition of pre-catalysts, activated catalysts, co-catalysts, reactants and products, i.e. questions of chemical selectivity, chemical confinement, and modulation of activity via control over catalyst metal-atom nuclearity, and general questions regarding emergent complexity in catalytic systems.

Abstract: Our research examines the pathological role of oxidative and proteotoxic stress in solar photodamage and skin cancer (melanoma and nonmelanoma), aiming at the design of novel redox-directed molecular strategies that eliminate cancer cells while protecting healthy tissue from environmental insult (including solar UV radiation). Screening synthetic and food factor-derived compound libraries, we have successfully identified and validated specific small molecule electrophilic cytoprotectants (such as cinnamon-derived cinnamaldehyde and achiote-derived bixin) that display potent cancer chemopreventive activity in vitro and in vivo. Genetic experiments revealed that cancer chemopreventive and UV-cytoprotective activities of these dietary electrophiles were dependent on activation of the NRF2-orchestrated cellular redox control system. In the context of pro-oxidant experimental cancer chemotherapy, we have demonstrated feasibility of repurposing clinical redox antimalarials (including artemisinin-endoperoxide phytochemicals) for oncogene-directed intervention targeting malignant melanoma through induction of cytotoxic oxidative stress that occurs downstream of c-MYC / TFRC (transferrin receptor 1) -induced alterations in cellular iron homeostasis

Resumo: Our group is interested in the synthesis of biologically active target molecules, and in the development of new synthetic methods that enable approaches to such targets. In this talk, I will describe recent work on the synthesis of an antibiotic / anticancer macrocyclic polyketide, stambomycin D, where we aim not only to complete a chemical synthesis of this natural product, but also to validate the hypothesis that the stereochemistry of this molecule can be assigned through biosynthetic considerations. I will also discuss recent work on the synthesis of bicyclo[1.1.1]pentanes, motifs that are of great interest as surrogates for 1,4-disubstituted arenes, alkynes, and tert-butyl groups in medicinal and agrochemistry. These 'unnatural' products can be accesses using radical-based methodologies, specifically through atom transfer radical addition (ATRA) reactions of alkyl and aryl halides with the precursor propellane, tricyclo[1.1.1.0^1,3]pentane. Results in the development and application of this chemistry will be described.

Resumo: A utilização de sistemas dispersos (emulsões e microemulsões) em Química Analítica data de várias décadas. Estes sistemas vêm sendo largamente empregados na análise de líquidos orgânicos, principalmente, porque são capazes de solubilizar substâncias polares e não polares devido ao arranjo observado entre as fases aquosa e oleosa. Neste contexto, vários métodos foram desenvolvidos para determinação de metais (e outros analitos inorgânicos) neste tipo de amostra, explorando a formação de emulsões e microemulsões. Estas abordagens se tornaram extremamente populares no país nas últimas duas décadas, especialmente devido ao enorme crescimento da demanda analítica na área petroquímica. Esta conferência tem por objetivo revisitar os métodos tradicionais, baseados na análise direta de sistemas dispersos, e também mostrar novas abordagens para o emprego destes sistemas em procedimentos de extração com finalidade analítica.

Em breve mais informações

Resumo: Phenylphenalenones and related compounds are phenolic natural products reported from the monocotyledonous plant families Haemodoraceae, Musaceae, Pontederiaceae, and Strelitziaceae. The structures of the aglycones are characterized by a tricyclic carbon nucleus with a lateral phenyl substituent (C₁₉ skeleton), which are usually decorated with up to four oxygen functionalities in different positions. In addition, oxa- and aza-derivatives (C₁₈O and C₁₈N skeletons) have been isolated from plants. Most of these compounds, here collectively referred as phenylphenalenones, occur as aglycones, but many glycosides are also reported.

The biosynthetic origin of the carbon atoms of the phenylphenalenone skeleton from two phenylpropanoid units and C-2 of acetate and the involvement of a linear diarylheptanoid intermediate has been demonstrated by NMR-based isotopic labeling studies. The early steps of the phenylphenalenone biosynthesis are catalyzed by enzymes of the phenylpropanoid and plant polyketide pathway. A putative intramolecular Diels-Alder reaction, which is thought to be involved in the cyclisation of the intermediary diarylheptanoid to form the phenylphenalenone nucleus, is still a matter of debate. Hydroxyl groups originate either from precursor phenylpropanoids or are introduced by hypothetical monooxygenases. Finally, most of the oxidative downstream steps, leading to oxa-derivatives phenylbenzoisochromenones (C₁₈O), recently were demonstrated to proceed spontaneously.

Phenylphenalenones having a C19 skeleton are pigments contributing to the color of flowers and surface cells of other above-ground plant parts and roots; such compounds are known to possess phototoxic properties. Studies on the biological functions revealed a role of phenylphenalenones in plant defense against herbivores and plant pathogens. Some phenylphenalenones and related metabolites possess antimicrobial and antifungal properties and are active against plant-parasitic nematodes. Phenylphenalenones seem to be constitutive natural products in the Haemodoraceae, where they function as phytoanticipins. In the Musaceae, phenylphenalenones are induced defense metabolites, meeting the definition of phytoalexins. A recently identified hydroxylactone/aldehyde intermediate in the pathway from C₁₈O- to C₁₈N-type compounds readily binds to the amino group of nitrogenous natural products, including the N-terminus of biogenic peptides and proteins, and therefore is discussed as the key player of a novel phenylphenalenone-based plant defense mechanism.

Resumo: In the last decades, the humankind has become a geological force and rivals with the great forces of nature in the impact and modification of the Earth system. The word Anthropocene was proposed by the scientists Paul Crutzen and Eugene F. Stoemer, in 2000, to describe this new age and capture the central human role in geology and ecology. A brief review of Anthropocene history, from the point of view of geology, chemistry and environmental sciences, will be presented showing the confluence of Chemistry and the main Anthropocene topics. Several approaches to define the beginning of Anthropocene has been proposed and will be discussed as well as the evidences that, from the point of view of chemistry, biology and environmental sciences, we are in a new epoch, different from Holocene. There is no doubt that mankind has modified the Planet in a dramatic extent, in some cases in an irreversible extent, and the Holocene concepts are not suitable to describe the new tendencies in the chemical and biological variables and the future of the earth system as a whole. The future depends on the approaches to manage humanity's relationship with the environment. Some approaches such as The Planetary Boundaries concept and the doughnut of social and planetary boundaries will be presented. Chemistry has a central role in the goal of identifying and maintaining a safe operating space in which humanity can pursue its further development and evolution.

Resumo: Semiconductor-based photocatalysis has received tremendous attention in the last few decades because of its potential for solving current energy and environmental problems. In a semiconductor photocatalytic system, photo–induced electron-hole pairs are produced when a photocatalyst is irradiated by light with frequencies larger than that of its band gap (hν ≥ Eg). The photo-generated charge carriers can either recombine, or migrate to the surface of the semiconductor, where they can be involved in electrochemical processes. High recombination rate of charge carriers and limited efficiency under visible light irradiation are two limiting factors in the development of efficient semiconductor-based photocatalysts. To overcome these drawbacks, the design and preparation of semiconductor heterojunctions using two or more semiconductors is a promising approach. Recently studied examples of these semiconductor heterojunctions will be presented to demonstrate that well designed heterojunctions can extend light absorption range and enhance the lifetime of photogenerated charge-carriers resulting in enhanced photocatalytic activity compared to their individual components. Plausible mechanism for the observed enhanced photocatalytic activity of the heterojunctions is proposed, and supported by photoluminescence and electrochemical impedance spectroscopy.

Synopsis
A large proportion of the compounds which enter clinical trials never make it to patients. So there is an urgent need to enhance our understanding of the interplay between small molecules, either from nature or designed in the laboratory, and the intricate network of cellular machinery for which they are intended. Integrating advanced imaging techniques into the early stages of drug-discovery campaigns may help to improve pre-clinical modelling studies and reduce the high attrition rates of clinical drug candidates. Stimulated Raman scattering (SRS) microscopy is a new imaging technique which can be used to detect specific chemical bonds within either the small molecule, or the cell, to give high contrast, label-free imaging and to provide intracellular quantification of small molecules.^[1,2] In this lecture, recent advances from our group will be discussed including: the design of synthetic Raman-active labels which exploit spectroscopically bioorthogonal functional groups; the use of both dual-colour SRS and multi-modal imaging to probe intracellular drug distribution and drug resistance mechanisms; and analysis of the quantitative data which SRS imaging provides to allow the kinetics of bioorthogonal reactions to be studied in the intracellular environment itself.

[1] ‘Imaging Drug Uptake by Bioorthogonal Stimulated Raman Scattering Microscopy’: W. J. Tipping, M. Lee, V. G. Brunton, A. N. Hulme, Chem. Sci., 2017, 8, 5606-5615.
[2] ‘Stimulated Raman Scattering Microscopy: An Emerging Tool for Drug Discovery’: W. J. Tipping, M. Lee, A. Serrels, V. G. Brunton, A. N. Hulme, Chem. Soc. Rev., 2016, 45, 2075-2089.

Biography
Prof Alison Hulme gained both her BA Hons in Natural Sciences and her PhD in Synthetic Organic Chemistry from the University of Cambridge. After completing postdoctoral work at Colorado State University, USA and returning to the UK to hold a College Fellowship at the University of Cambridge, she joined the academic staff at the University of Edinburgh in 1995. She was promoted from lecturer to senior lecturer, before taking up her Chair in 2017. Her research interests include the synthesis of bioactive natural products, bioorthogonal chemistry, and intracellular imaging. She collaborates with academic and industrial partners in the application of chemical tools to the fields of cancer, Parkinson’s disease, atherosclerosis and multiple sclerosis. Alison is President of the Organic Division Council of the Royal Society of Chemistry (2016–2019).

Abstract: From the contribution of African peoples and the diaspora to the development of science, I intend to present a proposal of antiracist education, from a perspective of non-hegemonic science, that is, presented only by the view of the universal subject: the white man. Also, to discuss about planning and development of pedagogical practices that discuss and expand the repertoire on the African continent, in order to refuse stereotypes and build critical sense in students of the second country in the world in black population - Brazil. The proposal intends to encompass a discussion about education for ethnic racial relations in chemistry class, affirmative action policies and law 10.639/03, which turned 16, changed the LDB (Law of Guidelines and Bases for National Education), making compulsory the study of African and Afro-Brazilian histories and cultures, and little has been discussed in chemistry classes.
In today's world, in the midst of ethnic-racial, religious or nationalist discussions and conflicts, our proposal is to raise the following issues:

• The tension on the epistemic displacement required by the chemistry curricula.
• The different experiences regarding ways in which teaching can promote education by considering alterity, understood as a fundamental human right.
• Stimulating the debate on the role of chemistry teaching, with a view to building positive social relationships and engaging in combating any form of discrimination through the implementation of law 10.639-03.

Resumo: A partir da contribuição dos povos africanos e da diáspora para o desenvolvimento da ciência, pretendo apresentar uma proposta de educação antirracista, por uma visão de ciência não hegemônica, ou seja, que se apresente apenas pela ótica do sujeito universal: o homem branco. Ainda abordar sobre planejamento e desenvolvimento de práticas pedagógicas que discutam e ampliem o repertório sobre o continente africano, a fim de recusar estereótipos e construir senso crítico em alunos do segundo país no mundo em população negra- o Brasil.  A proposta pretende contemplar uma discussão sobre a educação para as relações étnico racias em aula de química, políticas de ação afirmativa e a lei 10.639/03, que completou 16 anos, alterou a LDB (Lei de Diretrizes e Bases da Educação), tornando obrigatório o estudo de histórias e de culturas africanas e afro-brasileira e pouco tem sido discutida nas aulas de química.
No mundo atual, em meio a discussões e conflitos de natureza étnico-racial, religiosa ou nacionalista, nossa proposta é colocar como questões de pauta:

• A tensão sobre o deslocamento epistêmico necessários aos currículos de química.
• As diferentes experiências relativas a formas pelas quais o ensino pode promover a educação considerando a alteridade, entendida enquanto direito humano fundamental.
• Fomentar o debate sobre o papel do ensino de química, tendo em vista a construção de relações sociais positivas e o engajamento no combate a quaisquer formas de discriminação por meio da implementação da lei 10.639-03.

Resumo: A variety of new properties emerges in nanostructured metallic materials. These new properties are consequence of the collective excitation of conducting electrons, known as surface-plasmon resonances (SPR). For instance, the color of noble metals, such as gold and silver, can be controlled at the nanoscale by tuning the geometric characteristics of the nanostructures. A very interesting consequence of SPR is the phenomenon of electric field localization. Once the SPR condition is established, metallic nanostructures can act as tiny antennas that capture visible radiation and concentrate it in sub-wavelength regions. Molecules exposed to the localized fields can experience a large increase in their spectroscopic response. This leads to unique spectroscopic phenomena, such as the surface-enhanced Raman scattering (SERS) effect. The optical fields achieved in certain metallic nanostructures can be very strong and only accessible to a very small number of molecules (since they are also confined to very small regions). Ultimately, in certain conditions, SERS allows the detection of single adsorbed species. In this work, we will show that the spectroscopic response from single molecules is dynamic and carries information about the local field strength, resonance energy and local nanometric geometry. Moreover, the detection of single molecules leads to a new analytical quantification technology with very low limits of detection. Finally, we will also demonstrate that organized metallic nanostructures can also be used as a platform for single molecule spectroscopy. In that case, we will explore the plasmonics characteristics of single nanoapertures in gold films to follow fluctuations in spectroscopic response using methods for super-resolution imaging.

Resumo: Since the early reports on magnetic separation technology [1], magnetic particles (MPs) have been used as a powerful and versatile preconcentration tool in a variety of analytical and biotechnology applications. This technology has been widely incorporated for researchers in classical methods including PCR and immunoassays, and in emerging technologies such as biosensors and microfluidic devices with application ranging from biomarker detection of infectious diseases, foodborne pathogens, among others. Magnetic particles have been commercially available for many years. The use of MPs greatly improves the performance of the biological reaction by increasing the surface area, enhancing the washing steps and, importantly, minimizing the matrix effect. In addition, MPs can be easily magneto-actuated using permanent magnets. Beside the amazing properties and the huge range of applications, the main drawback of the biologically-modified MPs is their high cost and low stability at harsh conditions. Molecularly Imprinted Polymers (MIPs) are synthetic biomimetic materials mimicking biological receptors [2]. They are highly cross-linked macromolecular structures towards the template which is then extracted after polymerization, originating cavities (binding sites) complementary to the template molecule, acting as plastic antibodies. Although MIPs have in general lower affinity and selectivity compared to the biological counterparts, they show important technological features: i) they can be easily and affordably synthesized on a animal-free large scale procedures, and ii) they show high chemical and mechanical stability, allowing to work in harsh conditions (pH, temperature, solvents). This lecture addresses the synthesis of magneto-actuated molecularly imprinted polymers (magnetic-MIPs) in order to merge the outstanding properties of MIPs and MPs [3]. The characterization of the magnetic-MIP is performed by several techniques as SEM, TEM, XRD, FTIR, VSM and BET analysis. Finally, magnetic-MIP is used for preconcentration of the analyte from the complex samples allowing the quantification by the direct electrochemical detection on magneto-actuating electrodes. This novel material was evaluated, among others, in different applications including for the isolation and detection of biotin and biotinylated biomolecules [4], for food pollutants (methyl parathion) and contaminants (histamine) in fish samples as a model and it was also successfully applied for determination of diseases related to hormone (L-thyroxine) giving promising results [5]. This proves the ability of this material to preconcentrate analyte from complex samples and opens the way to incorporate this material in magneto-actuating devices which could be used easily in the field of environmental control, food safety, and medical applications.

References
1. A. Rembaum, R.C.K. Yen, D.H. Kempner, J. Ugelstad, 1982. J. Immunol. Methods 52, 341-351.
2. G. Vlatakis, L.I. Andersson, R. Müller, K. Mosbach, 1993. Nature 361, 645-647.
3. Pividori,M.I. , Sotomayor,M.D.P.T. , European Patent EP15169505.3.(2016).
4. AB Aissa, A Herrera-Chacon, RR Pupin, MDPT Sotomayor, MI Pividori, 2017. Biosensors and Bioelectronics 88, 101-108.
5. S. Lima Moura, L. Martinez Fajardo, L. dos Anjos Cunha, MDPT Sotomayor, F.B. Bolivar Correto Machado, L.F. Araújo Ferrão, MI Pividori, 2018. Biosensors and Bioelectronics 107, 203-210.

Resumo: The use of different inorganic and organic structure directing agents (OSDA) allows synthesizing zeolites with controlled pore topologies, chemical compositions and/or crystal sizes, to open new possibilities in industrially-relevant chemical processes. Different strategies will be presented for improvement of the efficiency in the preparation of some of these catalysts (i.e. solid yields or costs), their catalytic performance, and their resistance against catalyst deactivation.

First, the combined use of organometallic-complexes and other organic molecules as cooperative templates will be reviewed, to yield metal-containing small pore zeolites as very active and hydrothermally stable catalysts for the selective catalytic reduction (SCR) of NOx. Second, the synthesis of nanosized zeolites with very diverse pore topologies will be depicted, using non-surfactant based OSDA molecules and/or pre-crystallized zeolites as the silicon source, as well as their application as efficient catalysts in processes such as methanol-to-olefins (MTO), olefin oligomerization or aromatic alkylation. Finally, the use of OSDA molecules that mimic the transition state of target catalytic reactions will be discussed, demonstrating that the reaction rates are then accelerated.

Resumo: The Photobiology is the field of the science that studies the effects of the light on the biological systems. The use of light visible light to modulate biological response, known as Photobiomodulation process, have been used in many new approaches to the development of new techniques and new therapeutic strategies with the basic function of reestablishing in the cells, in the organs as well as in the body its integrity. This new research field is described as a "Regenerative Medicine". Together with the development of Nanotechnology used to design smart target drug delivery system (DDS), associated with small molecules, peptides, genes and active compounds lead to a new protocol useful for the treatment of cancer (brain cancer), skin disorders, and more recently neurodegenerative process as Parkinson, Alzheimer's. In this talk we will discuss how the combination of Nanotechnology, Photoprocess and Cell Therapy could be a new challenge for the treatment of CNS disorders and brain cancer.

Resumo: The colors of fruits and flowers provide contrast against the green-brown background of vegetation, serving as strong visual clues for frugivores and pollinators. Systematic studies of the chemistry and photochemistry of synthetic analogs of these pigments, combined more recently with quantum chemical predictions of molecular geometries, conformations and colors, are providing a deeper understanding of the effects of solvent, substituents, and complexation with metal ions and/or colorless organic molecules (copigments), as well as serving as inspiration for potential new applications. Currently we have a rather detailed understanding of the chemistry and photochemistry of anthocyanins, the pigments responsible for the majority of the red, purple and blue colors of fruits and flowers, due in large part to studies of synthetic analogs (i.e., substituted flavylium cations). However, anthocyanins and synthetic flavylium cations are of limited utility in practical applications due to poor chemical and thermal stability of the chromophore responsible for the visible colors, though stability can be enhanced by adsorption on clays. As a source of inspiration for practical applications, the less known pyranoanthocyanins are more promising. These burgundy-colored pigments are spontaneously formed during the maturation of red wines as the result of reactions of the anthocyanins with copigments and/or yeast metabolites present in the wine. Although wine pyranoanthocyanins are structurally quite complex, simple synthetic pyranoflavylium cation analogs can now be readily prepared (with electron-donating/-withdrawing substituents, attached heterocyclic or polycyclic aromatic rings etc.). These pyranoanthocyanin analogs are chemically much more stable than flavylium cations and quantum chemical predictions of their colors and their ground and excited state properties agree well with experiment, permitting in silico design of new compounds. In contrast to flavylium cations, many pyranoflavylium cations produce readily observable amounts of excited triplet states in solution and can sensitize singlet oxygen formation without being degraded. Redox potentials suggest that pyranoflavylium cations should be good photoredox catalysts and, because they have good two-photon absorption cross sections and exhibit cytotoxic activity in cell cultures in the presence of light, could serve as sensitizers for photodynamic therapy.

Leading references: V. O. Silva et al. J. Phys. Org. Chem. 2016, 29, 594–599; A. A. Freitas et al. Pure Appl. Chem. 2017, 89, 1761-1767; C. P. Silva et al. ACS Omega 2018, 3, 954-960; F. H. Quina; E. L. Bastos An. Acad. Bras. Ciênc. 2018, 90, 681-695; G. T. M. Silva et al. Appl. Clay Sci. 2018, 162, 478-486; A. A. Freitas et al. Photochem. Photobiol. 2018, 94, 1086-1091; G. T. M. Silva et al. Photochem. Photobiol. 2019, 95, 176-182; J. He et al. J. Braz. Chem. Soc. 2019, 30, 492-498; F. Siddique et al. Photochem. Photobiol. Sci. 2019, 18, 45-53.

Acknowledgments: Productive research collaborations [IST & UNL, Lisbon; Univ. Victoria, Canada; UC Riverside, USA; Tianjin University (TJU), China.; UF Viçosa, MG], fellowships (CAPES, CNPq) and funding [NAP-PhotoTech; INCT-Catálise (CNPq 465454/2014-3); CNPq (Universal grant 408181/2016-3); CAPES-FCT(Portugal); SPST-TJU, China] are gratefully acknowledged.

Resumo: Two of the United Nations sustainable development goals focus on "no hunger" and "good health". The first half of the 21^st Century will witness a significant growth in the global population and movement of those populations towards urban centers. Providing safe and secure food sources for those populations will be a challenge for science and scientists. Chemists play a role in providing sustainable agriculture through the development of technologies that will enable producers to increase yields while decreasing costs. They also play an important role in detecting, preventing, and treating infectious diseases that impact food production. This talk will introduce the biosecurity research laboratory at Kansas State University and discuss a number of food animal diseases and food processing treatments being investigated in this unique facility. This talk will also introduce several opportunities for chemists to impact bio- and agro-security.

Resumo: Extracellular nanotopographic features can provide important cues to cells that influence behaviors such as migration, activation, and differentiation. For instance, parallel ridges with dimensions similar to those of collagen fibers in the extracellular matrix are known to be able to bias the migration of cells bidirectionally. The mechanisms through which cell interact with external nanotopgraphy are not well understood, however. We have found that nanotopography can have a strong influence on cytoskeletal dynamics. On flat surfaces, actin polymerization occurs in disordered waves that are nucleated at randim positions within the cell. However, we have discovered that nanotopography can lead not only to the selective nucleation of actin polymerization, but also to the guidance of the subsequent polymerization waves. This phenomenon, which we have dubbed "esotaxis" (with eso- being Greek for "inner"), appears to be a universal feature of eukaryotic cells, although its details differ from cell type to cell type. We will discuss examples of how esotaxis allows us to control cellular behavior. For instance, introducing a bias in the direction of actin polymerization leads to a corresponding bias in the direction of migration. We have designed surfaces and fabricated that harness this phenomenon to drive not only bidirectional cell migration, but also unidirectional cell migration. We have also shown that although esotaxis is a broadly-conserved phenomenon in eukaryotic cells, its details are cell-type specific.