Os quimioterápicos antimicrobianos são considerados contaminantes emergentes, com a capacidade de criar resistência em bactérias. Têm sido o foco de inúmeras pesquisas relacionadas a impactos ambientais, mas no Brasil, as pesquisas sobre a sua ocorrência em ambientes aquáticos continentais e costeiros são escassas. A cidade de Ubatuba tem uma densidade demográfica cinco vezes maior que a média nacional, aumentada em até doze vezes no verão, pressionando ainda mais os ecossistemas da região. Os rios Acaraú, Lagoa-Tavares, Grande e Indaiá deságuam na baía de Ubatuba, comprometendo a qualidade das suas águas. Este trabalho investigou a contribuição da descarga desses rios para a ocorrência e distribuição de quimioterápicos antimicrobianos (fluoroquinolonas e sulfonamidas) na baía de Ubatuba. Foi analisado um total de 36 amostras de água superficial. As coletas foram realizadas no período seco/chuvoso de 2014/2015. Para a determinação e quantificação dos fármacos foi utilizada SPE como método de preparo de amostra e CLAE-MS/MS para a detecção e quantificação dos antimicrobianos estudados. As características físico-químicas pH, temperatura, salinidade, oxigênio dissolvido, potencial redox (ORP), além do Carbono Orgânico Dissolvido (COD) também foram determinados para caracterização das águas da região. A distribuição espaço-temporal dos fármacos e a possível associação com os demais dados investigados foi avaliada pela ferramenta quimiométrica CA, visando à extração da maior quantidade possível de informações. Os rios e, consequentemente a baía estavam impactados pelo despejo de esgoto doméstico e os seguintes quimioterápicos antimicrobianos foram encontrados: sulfametoxazol (SMX), sulfatiazol (STZ), sulfacloropiridiazina (SCP), sulfaquinoxalina (SQX) e norfloxacina (NOR). Observou-se uma variação espacial e temporal, nos perfis de contaminação revelados pela CA. / Antimicrobial chemotherapeutical agents are considered emerging contaminants capable of creating bacterial resistance. They have been the focus of numerous studies related to environmental impacts, but in Brazil, there is little research on their occurrence in continental and coastal aquatic environments. The city of Ubatuba has a population density five times higher than the national average, which may be increased up to twelve times during the summer, pushing further the region\'s ecosystems. The rivers Acaraú, Lagoa-Tavares, Grande and Indaiá flow into Ubatuba Bay, compromising the quality of its waters. This work investigated those rivers\' discharge contribution on the occurrence and distribution of antimicrobial chemotherapeutical agents (fluoroquinolones and sulfonamides) in Ubatuba Bay. Thirty-six samples of surface water were analyzed. The samples were withdrawn during the dry and rainy seasons of 2014 and 2015, respectively. For the determining and quantifying the antimicrobial chemotherapeutical agents, it was used SPE as a sample preparation method and HPLC?MS/MS for their detection and quantification. Physicochemical characteristics like pH, temperature, salinity, dissolved oxygen, and redox potential (ORP), as well as dissolved organic carbon (DOC) were also determined to characterize the waters of the region. The spatial-temporal distribution of the agents and their possible association with other investigated data was assessed by the chemometric tool CA, aiming at extracting the greatest possible amount of information. The rivers and, consequently, the bay were contaminated by domestic sewage discharges and the following antimicrobial chemotherapeutical agents were detected: sulfamethoxazole (SMX), sulfathiazole (STZ), sulfachloropyridiazine (SCP), sulfaquinoxaline (SQX), and norfloxacin (NOR). The contamination profiles revealed by the CA showed a spatial variation and a temporal one.

Os quimioterápicos antimicrobianos são considerados contaminantes emergentes, com a capacidade de criar resistência em bactérias. Têm sido o foco de inúmeras pesquisas relacionadas a impactos ambientais, mas no Brasil, as pesquisas sobre a sua ocorrência em ambientes aquáticos continentais e costeiros são escassas. A cidade de Ubatuba tem uma densidade demográfica cinco vezes maior que a média nacional, aumentada em até doze vezes no verão, pressionando ainda mais os ecossistemas da região. Os rios Acaraú, Lagoa-Tavares, Grande e Indaiá deságuam na baía de Ubatuba, comprometendo a qualidade das suas águas. Este trabalho investigou a contribuição da descarga desses rios para a ocorrência e distribuição de quimioterápicos antimicrobianos (fluoroquinolonas e sulfonamidas) na baía de Ubatuba. Foi analisado um total de 36 amostras de água superficial. As coletas foram realizadas no período seco/chuvoso de 2014/2015. Para a determinação e quantificação dos fármacos foi utilizada SPE como método de preparo de amostra e CLAE-MS/MS para a detecção e quantificação dos antimicrobianos estudados. As características físico-químicas pH, temperatura, salinidade, oxigênio dissolvido, potencial redox (ORP), além do Carbono Orgânico Dissolvido (COD) também foram determinados para caracterização das águas da região. A distribuição espaço-temporal dos fármacos e a possível associação com os demais dados investigados foi avaliada pela ferramenta quimiométrica CA, visando à extração da maior quantidade possível de informações. Os rios e, consequentemente a baía estavam impactados pelo despejo de esgoto doméstico e os seguintes quimioterápicos antimicrobianos foram encontrados: sulfametoxazol (SMX), sulfatiazol (STZ), sulfacloropiridiazina (SCP), sulfaquinoxalina (SQX) e norfloxacina (NOR). Observou-se uma variação espacial e temporal, nos perfis de contaminação revelados pela CA. / Antimicrobial chemotherapeutical agents are considered emerging contaminants capable of creating bacterial resistance. They have been the focus of numerous studies related to environmental impacts, but in Brazil, there is little research on their occurrence in continental and coastal aquatic environments. The city of Ubatuba has a population density five times higher than the national average, which may be increased up to twelve times during the summer, pushing further the region\'s ecosystems. The rivers Acaraú, Lagoa-Tavares, Grande and Indaiá flow into Ubatuba Bay, compromising the quality of its waters. This work investigated those rivers\' discharge contribution on the occurrence and distribution of antimicrobial chemotherapeutical agents (fluoroquinolones and sulfonamides) in Ubatuba Bay. Thirty-six samples of surface water were analyzed. The samples were withdrawn during the dry and rainy seasons of 2014 and 2015, respectively. For the determining and quantifying the antimicrobial chemotherapeutical agents, it was used SPE as a sample preparation method and HPLC?MS/MS for their detection and quantification. Physicochemical characteristics like pH, temperature, salinity, dissolved oxygen, and redox potential (ORP), as well as dissolved organic carbon (DOC) were also determined to characterize the waters of the region. The spatial-temporal distribution of the agents and their possible association with other investigated data was assessed by the chemometric tool CA, aiming at extracting the greatest possible amount of information. The rivers and, consequently, the bay were contaminated by domestic sewage discharges and the following antimicrobial chemotherapeutical agents were detected: sulfamethoxazole (SMX), sulfathiazole (STZ), sulfachloropyridiazine (SCP), sulfaquinoxaline (SQX), and norfloxacin (NOR). The contamination profiles revealed by the CA showed a spatial variation and a temporal one.

Philosophiae Doctor - PhD / Polyamic acid (PAA) nanostructured materials were successfully produced by electrochemical deposition and electrospinning using polyvinlypyrrolidone (PVP) as supporting polymer. Polyamic acid thin film and nanofibers were deposited directly at the surface of a screen-printed carbon electrode (SPCE) as electro-catalysts for reliable analytical reporting of sulphonamide as contaminants of emerging concern by electrochemical techniques. Fourier transform infrared (FTIR) spectroscopy was used to confirm the structural integrity of the PAA electrospun nanofibers compared to the chemical synthesized PAA. Brunauer-Emmett-Teller (BET) was used to determine the surface area of the nanofibers. The surface morphology and surface thickness of the polyamic acid (PAA) nanofibers on the screen-printed electrodes was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Cyclic voltammetry (CV) was used to study redox behavior of the nanostructured PAA modified screen-printed carbon electrodes. Electrochemical parameters surface concentration, diffusion coefficient, formal potential and peak separation were determined. Three sulphonamides were selected based on the United States of protection agency (US EPA) and World Health Organization (WHO) list of emerging contaminants and detected sulphonamides in environmental waters in South Africa and other African regions. The selected sulfonamides were evaluated at the unmodified and modified screen-printed carbon electrodes. The sulphonamides were evaluated in three different supporting electrolytes at pH < 7 and >7 to enhance electrochemical signal reporting. Sulfadiazine (SDZ), sulfamethoxazole (SMX) and sulfamethazine (SMZ) displayed peaks at 0.80 V vs Ag/AgCl in 0.1 M tris-HCl using square wave voltammetry at the unmodified transducer. At the PAA thin film transducer, SDZ, SMX and SMZ displayed well-defined analytical oxidative peaks at 0.77 V 0.82 V and 0.83 V vs Ag/AgCl respectively. The LOD (n=3) for SDZ was found to be 12.14 ųM with a correlation coefficient of 0.9950. The LOD (n=3) for SMX and SMZ was found to 14.59 ųM (R2 =0.9928) and 10.41 ųM (R2 =0.9963). These sulphonamides were also electro-analytical evaluated at the screen-printed carbon PAA nanofiber modified transducer. SDZ, SMX and SMZ produced well-defined analytical signals at 0.79 V, 0.81 V and 0.78 V vs Ag/AgCl respectively. The determined LOD (n=3) for the individual sulphonamides was 8.26 ųM, 16.59 ųM and 8.81 ųM SDZ, SMX and SMZ respectively. The linearity correlation coefficient (R2) was determined to be 0.9977, 0.9956 and 0.9974 respectively. The efficacy of the proposed nanostructured PAA thin film modified screen-printed carbon sensor was evaluated by performing recovery studies for the selected sulphonamides using square wave voltammetry. Tap water was used to simulate environmental matrix. The recoveries of SDZ with respect to each concentration were 98.84% (RSD 4.98%) to 40.58% (RSD 6.74%). For SMX the recoveries were 154.17% (RSD 11.00%) to 111.03% (RSD 16.80%). The recoveries for SMZ with respect to each concentration were 184% (RSD 8.19%) to 90.26 (RSD 18.26%) indicating the reliability of the analytical results. / 2021-09-01

Recent work has shown that sulfones are unique synthetic tools capable of undergoing numerous transformations and reactions. The sulfone group is a strong electron withdrawing group and has the ability to stabilize an α-sulfonyl carbanion. As such, unsaturated sulfones can undergo a variety of reactions, i.e. conjugate additions, alkylation etc. Beside this, α sulfonyl carbanion can be generated with strong base and α sulfonyl carbanion can also be used in various reactions. This report is an investigation of a novel base induced cyclization of various alkynyl sulfones. The results revealed that the reaction does not significantly depend on the electronic effects of substituents in the aromatic ring. Additional versatility in this process was demonstrated with respect to a diverse array of functionality at various positions i.e. benzylic position, aromatic ring and terminal position of alkyne. These alkynyl sulfones, bearing a larger group at ortho position and any group at benzylic position underwent intramolecular cyclization when treated with base affording benzothiopyran S,S-dioxide. The results demonstrated that the cyclization efficiency was significantly influenced by the steric effects of substituents of aromatic ring at ortho positions and blocking the terminal position with phenyl since the cyclization reaction gave low or no yields with aromatic rings having a substituent at para, meta or to position than those having no substituent. It was also found that 2-thiophenylmethyl sulfones cyclize more efficiently than benzyl and furfuryl sulfones. The evidence from mechanistic studies points to a mechanism for the cyclization that involves disruption of aromaticity. To disrupt aromaticity, a deprotonation at benzylic position is a requirement for this cyclization reaction. Results suggest that the cyclization also requires an available hydrogen at the point where the potential ring would be fused. Several intermediates were also observed spectroscopically and identified by ReactIR®.

Karboanhidrazės (CA) yra metalofermentai, katalizuojantys virsmus tarp anglies dioksido ir bikarbonato. Jų slopinimas gali būti taikomas gydyti tokias skirtingas ligas kaip glaukoma, vėžys, nutukimas, epilepsija, osteoporozė ir kt. Šiuo metu yra beveik 30 mažamolekulinių junginių, kurie naudojami kaip vaistai, su padidėjusiu karboanhidrazių aktyvumu susijusioms ligoms gydyti. Darbe tirta rekombinantinių žmogaus karboanhidrazių I, II, VII, IX ir XIII sąveika su sulfonamidiniais ligandais. Įvertintas tirtų baltymų stabilumas skirtingomis eksperimentinėmis sąlygomis, nustatyta priešvėžinio taikinio CA IX oligomerinė būsena. Modeliniais baltymais naudojant karboanhidrazes, praplėstos terminio poslinkio metodo taikymo ribos. Išmatuoti 40 naujų susintetintų junginių sąveikos su karboanhidrazėmis termodinaminiai parametrai, išanalizuota CA XIII sąveikos su sulfonamidiniais slopikliais termodinamika, atskiriant tikruosius, nuo eksperimento sąlygų ir susijusių reakcijų nepriklausančius jungimosi parametrus. / Carbonic anhydrases (CAs) are metalloenzymes that catalyze the conversion between carbon dioxide and bicarbonate. Their inhibition can be applied for treatment of different diseases, such as glaucoma, cancer, obesity, epilepsy, osteoporosis, etc. There are nearly 30 small molecule ligands that are used as drugs for carbonic anhydrase related diseases. In this work interaction between recombinant human carbonic anhydrases I, II, VII, IX, XIII and sulfonamide ligands was analysed. Stability of selected carbonic anhydrases was evaluated in different experimental conditions. Oligomeric structure of anticancer target CA IX was determined. Using carbonic anhydrases as model proteins, the application range of thermal shift assay was extended. Binding parameters of 40 new compounds to human carbonic anhydrases were measured. The binding thermodynamics of sulfonamide ligands to CA XIII was analyzed and intrinsic binding parameters, independent of the experimental conditions and linked protonation reactions, were determined.

Carbonic anhydrases (CAs) are metalloenzymes that catalyze the conversion between carbon dioxide and bicarbonate. Their inhibition can be applied for treatment of different diseases, such as glaucoma, cancer, obesity, epilepsy, osteoporosis, etc. There are nearly 30 small molecule ligands that are used as drugs for carbonic anhydrase related diseases. In this work interaction between recombinant human carbonic anhydrases I, II, VII, IX, XIII and sulfonamide ligands was analysed. Stability of selected carbonic anhydrases was evaluated in different experimental conditions. Oligomeric structure of anticancer target CA IX was determined. Using carbonic anhydrases as model proteins, the application range of thermal shift assay was extended. Binding parameters of 40 new compounds to human carbonic anhydrases were measured. The binding thermodynamics of sulfonamide ligands to CA XIII was analyzed and intrinsic binding parameters, independent of the experimental conditions and linked protonation reactions, were determined. / Karboanhidrazės (CA) yra metalofermentai, katalizuojantys virsmus tarp anglies dioksido ir bikarbonato. Jų slopinimas gali būti taikomas gydyti tokias skirtingas ligas kaip glaukoma, vėžys, nutukimas, epilepsija, osteoporozė ir kt. Šiuo metu yra beveik 30 mažamolekulinių junginių, kurie naudojami kaip vaistai, su padidėjusiu karboanhidrazių aktyvumu susijusioms ligoms gydyti. Darbe tirta rekombinantinių žmogaus karboanhidrazių I, II, VII, IX ir XIII sąveika su sulfonamidiniais ligandais. Įvertintas tirtų baltymų stabilumas skirtingomis eksperimentinėmis sąlygomis, nustatyta priešvėžinio taikinio CA IX oligomerinė būsena. Modeliniais baltymais naudojant karboanhidrazes, praplėstos terminio poslinkio metodo taikymo ribos. Išmatuoti 40 naujų susintetintų junginių sąveikos su karboanhidrazėmis termodinaminiai parametrai, išanalizuota CA XIII sąveikos su sulfonamidiniais slopikliais termodinamika, atskiriant tikruosius, nuo eksperimento sąlygų ir susijusių reakcijų nepriklausančius jungimosi parametrus.

Grâce à leurs fortes acidités, les milieux superacides permettent d’accéder par polyprotonation à des intermédiaires superélectrophiles polycationiques, capables d’être piégés par des nucléophiles très faibles. Ces espèces très réactives ont permis de développer des méthodologies de synthèse sans équivalent en conditions « classiques ».Dans la première partie de ce travail, le comportement de composés organophosphorés dans le milieu HF/SbF5 a été évalué et les sites de protonation de différentes fonctions phosphorées ont pu être observés par RMN in situ à basse température. La réactivité d’oxydes de phosphines insaturés a également été évaluée et des composés organophosphorés cycliques et/ou fluorés ont été synthétisés avec de bons rendements. Des expériences de RMN in situ à basse température ont permis de mettre en évidence un intermédiaire superélectrophile de type phosphonium-carbénium inédit dont l’implication a été confirmée par des calculs théoriques.La deuxième partie est consacrée à l’exploitation de la contrainte benzylique d’espèces superélectrophiles. A partir d’éphédrines tosylées, des benzosultames cycliques ont été obtenus par cyclisation intramoléculaire diastéréospécifique dans l’acide trifluorométhanesulfonique. L’analyse des intermédiaires réactionnels par RMN a permis de révéler l’implication d’une contrainte benzylique contrôlant la spécificité de la réaction. Les benzosultames chiraux N-F obtenus après fluoration ont été utilisés comme réactifs de fluoration électrophile énantiosélective et la synthèse de dioxydes de méthanodibenzothiazocines chiraux inédits a également été envisagée. / Thanks to their exceptional acidity, superacid allow access to polycationic superelectrophiles by polyprotonation. These highly reactive species are capable of being trapped by very weak nucleophiles and can be used to develop new synthetic methodologies without equivalents under “classical” conditions. In the first part of this work, the behavior of organophosphorus compounds in HF/SbF5 was evaluated and the protonation sites of different phosphorus functions have been observed by low temperature NMR spectroscopy. The reactivity of unsaturated phosphine oxides has also been evaluated and cyclic and/or fluorinated organophosphorus compounds have been synthetized in good yields. In situ low-temperature NMR experiments revealed a phosphonium-carbenium superelectrophilic intermediate whose implication was confirmed by theoretical calculations. The second part deals with the study of the benzylic strain applied to superelectrophilic species. From tosylated ephedrines, cyclic benzosultams were obtained by diastereospecific intramolecular process in trifluoromethanesulfonic acid. Analysis of the reaction intermediates by NMR revealed the implication of a benzylic strain controlling the specificity of the reaction. After fluorination, the obtained N-F chiral benzosultams were used as enantioselective electrophilic fluorination reagents and the synthesis of new chiral methanodibenzothiazocine dioxides was also considered.

Les réactions multicomposants sont des réactions faisant intervenir au minimum trois composés pour la préparation d'un produit contenant la majeure partie des atomes de départ. Elles constituent l'un des procédés les plus performants en synthèse organique. En diminuant les coûts et les rejets par rapport aux réactions classiques de chimie organique, elles sont également plus économes et plus respectueuses de l'environnement. De plus, en permettant la formation rapide et efficace d'une large librairie de molécules complexes à partir de substrats simples, elles représentent un outil à forte valeur ajoutée dans le domaine pharmaceutique pour l'élaboration de chimiothèques. Face à ces enjeux, le laboratoire a développé en 2006 une réaction multicomposants de type Mannich entre des organozinciques, des amines et des aldéhydes. Cette réaction permet la synthèse efficace d'une variété importante de diarylméthylamines, dont la structure amine α,α-disubstituée est rencontrée dans de nombreux composés d'intérêt pharmacologique.A partir de ces travaux, il a été envisagé d'étendre la réaction multicomposants à la préparation de β-amino esters N-protégés. La réaction a été mise au point à partir d'un acrylate, d'une imine préformée et d'un organozincique aromatique formé in situ dans des conditions de type Barbier. Ces conditions opératoires présentent l'avantage d'éviter l'étape préliminaire de formation de l'organométallique.Par la suite, lors d'essais portant sur le développement d'une réaction à quatre composants entre un aldéhyde, un sulfonamide, un acrylate et un halogénure aromatique, nous avons observé, lorsque le manganèse est utilisé comme réducteur du bromure de cobalt, la formation majoritaire d'un diarylméthylsulfonamide résultant d'une nouvelle réaction à trois composants entre l'aldéhyde, l'amine primaire et le dérivé halogéné. Les conditions opératoires ont donc été optimisées afin de synthétiser de nombreuses diarylméthylsulfonamides.Enfin, en se basant sur la différence de réactivité des deux atomes de brome d'un composé dibromé, il a été envisagé la synthèse en deux étapes d'indolines en partant de bromure de benzyle ortho-bromé, par l'intermédiaire d'une réaction de Mannich benzylique puis une seconde étape d'amination aromatique intramoléculaire, catalysée au palladium. / Multicomponent reactions are processes in which at least three starting materials react together to form a product containing most of the starting atoms. They constitute one of the most efficient processes in synthetic organic chemistry. They are also more economical and environmentally friendly than classic organic reactions. Moreover, since they allow a straightforward access to large libraries of compounds containing the same core unit, they represent a valuable tool for pharmaceutical industries, especially for high-throughput screening. In 2006, the laboratory developed a Mannich-type multicomponent reaction between aromatic organozinc compounds, aldehydes and secondary amines allowing the efficient preparation of diarylmethylamines. These structures, and more generally the α,α-disubstituted amine core unit, are found in a large range of compounds displaying diverse pharmacological properties. On the basis of this work, it was planned to extend the reaction to other families of compounds, N-protected β-amino esters and diarylmethylsulfonamides. In the first part of this work, a range of β-amino esters have been prepared starting from in situ-generated aromatic organometal compounds (Barbier-like conditions), acrylates and preformed sulfonylimines. These conditions present the advantage to avoid the pre-formation of the organometallic compound. Thereafter, during tests pertaining to the development of a four component reaction between an aldehyde, a sulfonamide, an acrylate and an aromatic halide, it was observed the major formation of diarylmethylsulfonamide resulting from the three-component reaction between the aldehyde, the primary amine and the halide, when manganese is used as the reducer of cobalt bromide. The experimental conditions were thus optimized in order to synthesize many diarylmethylsulfonamides.Lastly, based on the difference of reactivity between benzylic and aromatic C-Br bonds, it was described the two-step synthesis of various 1,2-substituted indolines starting from ortho-brominated benzyl bromide by means of a benzylic Mannich-like reaction followed by palladium-catalyzed intramolecular amination of the aromatic ring

No description available.

<p>Resistance to antimicrobials is an increasing problem in the world of today, and develops faster than man can counter. It is therefore of importance to study metabolic pathways in order to develop new antibiotics, but also to understand how resistance spreads and stabilizes in microbial populations.</p><p>The commensal flora could be an important factor in the spread of antimicrobial resistance, as drugs aimed at other targets also hit the harmless commensal bacteria. If stable resistance develops in such a population, it could seriously impair a later treatment with the same drug. After a treatment with the macrolide clarithromycin, resistance to this antibiotic increased markedly in the untargeted throat flora, and resistance levels did not recede until at least one year later. </p><p>Another example of stable resistance can also be seen in sulfonamide resistant <i>Streptococcus pyogenes</i>. Sequence determinations of the dihydropteroate synthase (<i>dhps</i>) gene conferring this resistance revealed a mosaic organisation implying that the it had been brought there by horizontal transfer. Molecular characterization of this gene showed that the sulfonamide resistance was due to mutations of structurally important amino acids in position 65 and 213.</p><p>The folate synthesis pathway has potential for being exploited further as a drug target. One possible new drug target is hydroxymethyl-dihydropterin pyrophosphokinase (<i>hppk</i>). In the malaria parasite <i>Plasmodium falciparum</i> this enzyme is part of a polyfunctional entity, also encoding <i>dhps</i>. The HPPK part can be separated from DHPS, but that the opposite is not possible. The PfHPPK has two insertions: one also present in other plasmodia, and one apparently unique to <i>P. falciparum</i>. Both are crucial for enzyme activity.</p><p>To further characterize HPPK, we developed a spectrophotometric activity assay and a method to measure substrate channelling of hydroxymethyl-dihydropterin diphosphate.</p>