As elevadas taxas de colesterol plasmático representam um grande risco à saúde, uma vez que podem causar doenças cardiovasculares. Para o tratamento e prevenção da dislipidemia são utilizados medicamentos reguladores do colesterol, como as estatinas. Embora eficazes e extensamente utilizados, esses fármacos apresentam efeitos adversos se administrados na dosagem errada. Assim, faz-se necessário o desenvolvimento de um método de monitorização terapêutica a fim de se ajustar a concentração desses compostos no sangue. Este trabalho visa o desenvolvimento de um método para análise de pravastatina (PRA), atorvastatina (AT), fluvastatina (FLV) e sinvastatina (SV) em plasma humano usando cromatografia líquida acoplada à espectrometria de massas (LC-MS). Na etapa de preparo de amostras, de forma inédita, utilizou-se a técnica microextração por sorvente empacotado (MEPS) para a análise de plasma humano contendo quatro estatinas. Para a otimização das condições de extração avaliaram-se, por experimentos univariados, parâmetros como fase extratora, composição do solvente de eluição e de lavagem. Outros fatores como volume de amostra, ciclos de amostragem, ciclos de eluição e etapas de eluição foram avaliados empregando-se planejamento experimental multivariado. A extração foi realizada utilizando-se uma fase estacionária C18 Chromabond como sorvente. O método MEPS-LC-MS/MS desenvolvido foi validado baseando-se nas recomendações da agência nacional de vigilância sanitária (ANVISA) e apresentou linearidade, seletividade, precisão, exatidão e recuperação adequadas para as estatinas, excetuando-se para a sinvastatina. A faixa de linearidade obtida foi de 10-200 ng mL-1 (FLV e AT) e 20-200 ng mL-1 (PRA). Os limites de quantificação obtidos foram da ordem de 10 ng mL-1 (AT e FLV) e 20 ng mL-1 (PRA). Desta forma o método desenvolvido poderá ser utilizado para a determinação dos níveis de pravastatina, fluvastatina e atorvastatina em amostras de plasma humano. / Elevated plasma cholesterol level is a risk factor for coronary diseases, which are the most deadly sickness according to the World Health Organization (WHO). In order to fight the hypercholesterolemia in patients, statins are a well-established class of drugs to be prescribed. Even though they are efficient, some side effects can be associated with statin therapy, especially when interactions with other drugs occur. In these cases, monitoring the concentration can optimize the drug dosage to therapeutic effectiveness whilst minimizing the adverse effects. The aim of this work was to develop a method for analysis of pravastatin (PRA), atorvastatin (AT), fluvastatin (FLV) and simvastatin (SV) in human plasma. The experimental means chosen to attain the goal was liquid chromatography-tandem mass spectrometry (LC-MS/MS) and for the sample preparation, microextraction by packed sorbent (MEPS). To optimize the extraction conditions, parameters such as sorbent, elution and washing solution were evaluated. Other parameters such as sampling, elution cycles, sample volume and elution steps were evaluated using multivariate experimental design. The extraction was performed using C18 Chromabond as sorbent. The method was validated based on ANVISA recommendations and featured appropriated linearity, selectivity, accuracy, precision, and recovery, except for simvastatin. The calibration curve in plasma was obtained in the concentration range 10-200 ng mL-1 (FLV and AT) and 20-200 ng mL-1 (PRA) and the limit of quantification (LOQ) was 10 ng mL-1 (FLV and AT) and 20 ng mL-1 (PRA). The method developed proved to be suitable for the analysis of pravastatin, fluvastatin and atorvastatin in human plasma sample, but not simvastatin, and it can contribute to a more efficient usage of the statins in the treatment of hypercholesterolemia.

En milieu marin, toute surface immergée est soumise à une colonisation par de nombreux organismes (biofouling). Le développement de biofilms est une étape clé du phénomène. Les systèmes de communication y sont contrôlés par le biais de signaux chimiques. Dans ce travail, l’étude de la signature métabolique de biofilms naturels formé in situ a été réalisée selon un gradient de pollution en contaminants métalliques dans la rade de Toulon et selon la nature du revêtement de la surface immergée. De nettes variations chimiques des biofilms prélevés sont observées et sont corrélées avec des variations en termes de communauté microbiennes. L’étude in vitro de 4 souches bactériennes issues de biofilms naturels a permis, après optimisation des méthodologies d’analyse, une discrimination selon leur profil métabolique. Des biomarqueurs ont été mis en évidence, avec notamment la production de lipides ornithine par la souche Pseudoalteromonas lipolytica. La réponse biologique de cette souche en fonction de son phénotype et face à un stress cuprique a été étudiée par métabolomique et protéomique révélant d’importantes modulations de certaines voies biosynthétiques. / In the marine environment, any immersed surface is subjected to colonization by many organisms (biofouling). The biofilms development is a key stage of this phenomenon. Communication systems are controlled in these structures by chemical signals. In this work, the study of the chemical signature of natural biofilms formed in situ was carried out among a gradient of contamination of metal contaminants in the bay of Toulon and according to the nature of the coating on the immersed surface. Clear chemical variations of the biofilms collected were observed and were correlated with variations in microbial community. The in vitro study of 4 bacterial strains harvested from natural biofilms allowed, after optimization of the analysis methodologies, their discrimination according to their metabolic profile. Biomarkers were highlited, particularly ornithine lipids production by the Pseudoalteromonas lipolytica strain. The biological response of this strain depending on its phenotype and face to copper stres was studied by metabolomics and proteomics revealing important modulations of certain biosynthetic patways.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-10-29T14:34:23Z No. of bitstreams: 2 Dissertação - Iury Valentim Jorge Zoghaib - 2013.pdf: 1607539 bytes, checksum: d92b3313edee2773935cb667be5b908d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-10-30T10:48:45Z (GMT) No. of bitstreams: 2 Dissertação - Iury Valentim Jorge Zoghaib - 2013.pdf: 1607539 bytes, checksum: d92b3313edee2773935cb667be5b908d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-10-30T10:48:45Z (GMT). No. of bitstreams: 2 Dissertação - Iury Valentim Jorge Zoghaib - 2013.pdf: 1607539 bytes, checksum: d92b3313edee2773935cb667be5b908d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-10-18 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The LQFM030 was obtained by molecular simplification of nutlins (inhibitors of p53-MDM2 interaction) and, having demonstrated excellent antineoplastic activity in vitro (cytotoxicity against K-562 cell line with IC50 = 23 M) and in vivo against Ehrlich ascitic tumor with increased survival in treated animals developed the pharmacokinetic study of p.o. in rats. It was used for LC-MS/MS analytical method (Applied Biosystems MDS Sciex API 3200) previously validated together. O LQFM030 was administered to 3 rats (mean weight 186g) in predetermined dose of 100 mg/kg by gavage. After administration, samples were collected from 1.0 mL of blood by cannulation of the left jugular vein with heparinized syringe, the intervals 0-8 h. The blood samples were identified and centrifuged to obtain plasma which was frozen at -20°C until analysis. The kinetic parameters were calculated in the software WinNonlin 5.0 (Pharsight™). Results (mean ± SD) half-life (t1/2) 3.61 ± 0.68 h, total clearance (CLT) 36.49 ± 2.23 mL/min/kg, volume of distribution (Vd) 11,40 ± 1.58 L/kg. The LQFM030 had low value of t1/2, Vd high and high value of CLT. These values allow us to understand that the prototype study demonstrated a good safety profile of tissue distribution and/or has been extensively eliminated. When compared with the kinetic parameters obtained in other studies, it was observed difference in results is justified by the high interspecies variability, mainly in basal metabolic rate and body weight, once the route of administration, orally and intraperitoneally, are kinetically similar. / O LQFM030 foi obtido por simplificação molecular dos nutlins (inibidores da interação MDM2-p53) e, tendo demonstrado excelente atividade antineoplásica in vitro (citotoxicidade contra a linhagem celular K-562 com IC50 = 23 M) e in vivo contra tumor ascítico de Ehrlich, com aumento de sobrevida em animais tratados, desenvolveu-se o estudo do perfil farmacocinético, p.o., em ratos. Empregou-se método analítico em LC-MS/MS (Applied Biosystems MDS Sciex API 3200) previamente validado em colaboração. O LQFM030 foi administrado a 3 ratos (peso médio de 186g), em dose preestabelecida de 100 mg/kg, por gavagem. Após a administração, foram coletadas amostras de 1,0 mL de sangue, por canulação da veia jugular esquerda, com seringa heparinizada, nos intervalos de tempo de 0 a 8 h. As amostras sanguíneas foram identificadas e centrifugadas para obtenção do plasma, que foi congelado a -20ºC até o momento da análise. Os parâmetros cinéticos foram calculados no software Winnonlin 5.0 (Pharsight™). Resultados (média ± DP): meia-vida (t1/2) 3,61 ± 0,68 h; clearance total (CLT) 36,49 ± 2,23 mL/min/kg; volume de distribuição (Vd) 11,40 ± 1,58 L/kg. O LQFM030 apresentou baixo valor de t1/2, elevado Vd e elevado valor de CLT. Estes valores permitem entender que o protótipo estudado demonstrou um bom perfil de distribuição tecidual e/ou foi extensivamente eliminado. Quando comparados com parâmetros cinéticos obtidos em outros estudos, observou-se diferença nos resultados, justificada pela elevada variabilidade interespécies, principalmente na taxa de metabolismo basal e peso corporal, uma vez que as vias de administração, oral e intraperitoneal, são cineticamente semelhantes.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A rapid, specific and highly sensitive liquid chromatography-tandem mass spectrometry method was developed to determine nimodipine in human plasma using dibucaine as the internal standard (IS) is described. The analyte (m/z 418,6 > 342,6) and IS (m/z 344,2 > 271,0) were extracted from plasma samples by liquid-liquid extraction using hexane-ethyl acetate (1:1v/v). Chromatography was performed on a Varian Polaris C18 analytical column (3 micrometer, 50 x 2,0 mm) and pre-column SecurityguardTM C18 (4,0 x 3,0 mm). The phase mobile consisted of Acetonitrile-Ammonium acetate 0.02 ml/L (80:20v/v). The method had a chromatographic run time of 4.5 min and linear calibration curve over the range 0.1- 40 ng/mL (r2 > 0.9938). The limit of quantification (LQ) was 0.1 ng/mL. The intra-day precision for the limit quantification was 0.00% (batch 01), 5.71% (batch 02) and 5.27% (batch 03); for the quality controls low (QCL), middle (QCM) and high (QCH) the results were respectively 8.57, 0.81 and 1.37%. The inter-day precision for LQ and QCL, QCM and QCH were respectively: 7% and 5.46, 4.12 and 3.37%. The intra-day accuracy for LQ was 110, 96 and 104%; for QCL, QCM and QCH the results were100.67, 109.09 and 109.72% respectively. The results of the inter-day accuracy for LQ, QCL, QCM and QCH were respectively and 110.0, 96.0, 104.0% for the limit of quantification and 8.57, 0.81, 1.37% and 100.67, 109.09, 109.72% respectively: 103% e 102.89, 106.60, 109.69%. This validated method was successfully applied for the pharmacokinetic profiles of nimodipine tablets administered to 24 healthy volunteerâs participant of bioavailability comparative study. Geometric mean of Test formulation/Refernce formulation individual percent ratio was 104,56% for AUC0-48h and 55,73% for Cmax. The 90% for the confidence intervals (CI) were 94,80-115,32% e 44,73-69,42%, respectively. The values of half-life and Cmax for test formulation and reference formulation were 27,83;32,78h and 9,48;18,76ng/mL, respectively. The values of Tmax were 2,34;0,98h for the formulations test and reference respectively. Since the 90% CI for Cmax and AUC0-48h, were within the 80-125% interval proposed by the âFood and Drug Administrationâ and ANVISA, it was concluded that the two formulations of nimodipine 30mg tablets were not bioequivalent, according to the rate of absorption after single dose administration. / Um mÃtodo rÃpido, sensÃvel e especÃfico de Cromatografia LÃquida de Alta EficiÃncia acoplada à Espectrometria de Massa (LC-MS-MS) foi desenvolvido para determinar nimodipino (analito) em plasma humano usando dibucaÃna como padrÃo interno (PI). O analito (m/z 418,6 > 342,6) e o PI (m/z 344,2 > 271,0) foram extraÃdos de amostras de plasma atravÃs de extraÃÃo lÃquido-lÃquido utilizando hexano-acetato de etila (1:1v/v). As corridas cromatogrÃficas foram executadas utilizando-se uma coluna analÃtica Varian Polaris C18 (3 micrÃmetros, 50 x 2,0 mm) e uma prÃ-coluna SecurityguardTM C18 (4,0 x 3,0 mm). A fase mÃvel consistiu de acetonitrila-soluÃÃo de acetato de amÃnio 0,02 mol/L (80:20v/v). O mÃtodo teve um tempo total de corrida de 4,5 min e uma curva de calibraÃÃo linear que variou de 0,1-40 ng/mL. O limite de quantificaÃÃo de 0,1 ng/mL. A precisÃo intra-ensaio para o limite de quantificaÃÃo (LQ) foi 0,00% (lote 01), 5,71% (lote 02) e 5,27% (lote 03); para os controles de qualidade baixo (CQB), mÃdio (CQM) e alto (CQA) os resultados foram respectivamente: 8,57, 0,81 e 1,37%. A precisÃo interensaio para o LQ e os CQB, CQM e CQA foram respectivamente de: 7% e 5,46, 4,12 e 3,37%. A exatidÃo intra-ensaio para o LQ foi 110, 96 e 104%; para CQB, CQM e CQA os resultados foram 100,67, 109,09 e 109,72% respectivamente. Os resultados da exatidÃo interensaio para o LQ, CQB, CQM e CQA foram respectivamente de: 103% e 102,89, 106,6, 109,69%. Este mÃtodo foi aplicado para a avaliaÃÃo do perfil farmacocinÃtico do nimodipino administrado em 24 voluntÃrios sadios participantes de um estudo de biodisponibilidade comparativa. A mÃdia geomÃtrica da FormulaÃÃo teste/FormulaÃÃo referÃncia para as porcentagens individuais foi 104,56% para ASC0-48h e 55,73% para Cmax. Os intervalos obtidos a partir do intervalo de confianÃa (IC) de 90% foram 94,80-115,32% e 44,73-69,42% respectivamente. Os valores de meia-vida e Cmax para as formulaÃÃes teste e referÃncia foram de 27,83;32,78h e 9,48;18,76ng/mL, respectivamente. Os valores de Tmax foram de 2,34;0,98h para as formulaÃÃes teste e referÃncia, respectivamente. Considerando o IC de 90% para Cmax e ASC0-48h dentro da variaÃÃo de 80-125% proposto pelo Food and Drug Administration e ANVISA, as duas formulaÃÃes de nimodipino 30mg nÃo sÃo bioequivalentes quanto à taxa de absorÃÃo (Cmax) apÃs uma Ãnica administraÃÃo.

FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / AtravÃs da cromatografia lÃquida de alta eficiÃncia com detecÃÃo por espectrometria de massa no modo MS/MS, desenvolveu-se um mÃtodo sensÃvel e altamente seletivo para determinar os nÃveis de acetato de megestrol no plasma humano, usando a betametasona como padrÃo interno. O analito e o padrÃo interno foram extraÃdos das amostras do plasma atravÃs da soluÃÃo de extraÃÃo hexano-acetato de etila (1:1 v/v), e cromatografados em uma coluna C18. A fase mÃvel consistiu de acetonitrila-Ãgua (80:20 v/v), contendo 0,1% de Ãcido fÃrmico. A detecÃÃo foi realizada em um triplo-quadrupolo, atravÃs de um espectrÃmetro de massa no modo de monitoramento de reaÃÃo mÃltipla via eletrospray. O mÃtodo tem um tempo de corrida de 3 minutos e limite de quantificaÃÃo de 2 ng/mL. As curvas de calibraÃÃo foram obtidas utilizando uma faixa de concentraÃÃo de 2 a 150 ng/mL. As precisÃes intralote foram 3,16%, 4,65% e 2,68%, e a acurÃcia intralote foi de 6,77%, 6,23% e 5,73% para 6, 60 e 120 ng/mL, respectivamente. As precisÃes interlote foram 7,76%, 6,23% e 6,37%, e a acurÃcia interlote foi de 0,08%, 1,55% e 2,11% para as mesmas concentraÃÃes. Este mÃtodo validado foi aplicado com sucesso para a determinaÃÃo dos parÃmetros farmacocinÃticos dos comprimidos de acetato de megestrol administrados a 30 voluntÃrios sadios. / A sensitive and highly selective liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed to determine megestrol acetate in human plasma using betamethazone as the internal standard. The analyte and internal standard were extracted from plasma samples by hexane/ethyl acetate (1:1 v/v), and chromatographed on a C18 column. The mobile phase consisted of acetonitrila-water (80:20 v/v) including formic acid 0.1%. Detection was performed on a triple quadropole tandem mass spectrometer by multiple reaction mode via electrospray source. The method has a chromatographic run time of 3 min and a limit of quantification of 2 ng/mL. The linear calibration curves were obtained in the concentration range 2 â 150 ng/mL. The intra-batch precisions were 3.16%, 4.65%, and 2.68%; and the intra-batch accuracy was 6.77%, 6.23%, and 5.73% for 6, 60 and 120 ng/mL, respectively. The inter-batch precision was 7.76%, 6.23%, and 6.37% and the inter-batch accuracy was 0.08%, 1.55%, and 2.11% for the same concentrations. This validated method was successfully applied for the determination of pharmacokinetic profiles of megestrol acetate tablets administered to 30 healthy volunteers.

O quadro evolutivo da agricultura brasileira resulta em benefícios à população exigindo crescentes avanços tecnológicos no setor. Constantemente, novos agrotóxicos são introduzidos estimulando estudos científicos com a finalidade de determinar e avaliar os impactos na população e no meio ambiente. No presente trabalho, a matriz avaliada foi o lodo gerado no processo de tratamento de água para consumo humano, coletado na região do Vale do Ribeira, SP. A técnica empregada foi a cromatografia líquida de fase reversa acoplada à espectrometria de massas triploquadrupolar em tandem com ionização por electrospray. Os compostos foram extraídos previamente da matriz. O desenvolvimento da metodologia exigiu tratamento dos dados para que esses pudessem ser utilizados e transformados em informações confiáveis. Os processos envolvidos foram avaliados usando o conceito da validação de ensaios químicos. Os indicadores avaliados foram seletividade, linearidade, intervalo de trabalho, sensibilidade, exatidão, precisão, limite de detecção, limite de quantificação e robustez. Esses indicadores produziram valores quantitativos e qualitativos que foram estatisticamente evidenciados de forma objetiva. A metodologia desenvolvida e validade é simples. Como resultado, mesmo explorando a sensibilidade da técnica, os compostos estudados não foram encontrados no lodo da ETA de Registro. Isso leva a crer que esses compostos podem estar presentes em concentrações muito baixas, podem sofrer degradação durante o tratamento da água ou não são retidos completamente pela ETA. 7 / The evolving scenario of Brazilian agriculture brings benefits to the population and demands technological advances to this field. Constantly, new pesticides are introduced encouraging scientific studies with the aim of determine and evaluate impacts on the population and on environment. In this work, the evaluated sample was the sludge resulted from water treatment plant located in the Vale do Ribeira, São Paulo, Brazil. The technique used was the reversed phase liquid chromatography coupled to electrospray ionization tandem mass spectrometry. Compounds were previously liquid extracted from the matrix. The development of the methodology demanded data processing in order to be transformed into reliable information. The processes involved concepts of validation of chemical analysis. The evaluated parameters were selectivity, linearity, range, sensitivity, accuracy, precision, limit of detection, limit of quantification and robustness. The obtained qualitative and quantitative results were statistically treated and presented. The developed and validated methodology is simple. As results, even exploring the sensitivity of the analytical technique, the work compounds were not detected in the sludge of the WTP. One can explain that these compounds can be present in a very low concentration, can be degraded under the conditions of the water treatment process or are not completely retained by the WTP.

O número crescente de descobertas de substâncias bioativas produzidas pelo metabolismo secundário de cianobactérias tem despertado o interesse de grupos de pesquisa no mundo todo com o objetivo comum de descrever e explorar estas moléculas e entender a sua biossíntese. No Brasil, as pesquisas sobre moléculas bioativas produzidas por linhagens de cianobactérias nativas são escassas. Neste trabalho, utilizando iniciadores específicos da PCR e sequenciamento, a presença de genes envolvidos na biossíntese da neurotoxina saxitoxina (STX) foi confirmada em representantes dos gêneros Dolichospermum, Sphaerospermopsis, Cuspidothrix e Cylindrospermopsis, enquanto que genes da citotoxina cilindrospermopsina (CYN) foram detectados somente em representantes de Cylindrospermopsis. Genes envolvidos com a produção dos inibidores enzimáticos, microviridina (MDN) e a cianobactina microciclamida (MCA) foram sequenciados em isolados do gênero Microcystis. Os genomas das linhagens de Cylindrospermopsis raciborskii CENA302 e CENA303 foram sequenciados usando a plataforma HiScan SQ (Ilumina) com biblioteca pareada 2 x 100 pb. O genoma da Sphaerospermopsis torques-reginae ITEP-024 foi sequenciado utilizando a plataforma Ion Torrent (Life Technologies) com tamanhos de fragmentos de até 200 pb. As tentativas de montagem ab initio dos genomas foram realizadas e o agrupamento gênico da saxitoxina (28 kb) da linhagem C. raciborskii CENA302 foi identificado e caracterizado. As análises filogenéticas das sequências de aminoácidos envolvidos com a biossíntese das moléculas bioativas avaliadas demonstraram que os isolados brasileiros de cianobactérias formam clados com elevado valor de reamostragem com sequências homólogas de cianobactérias conhecidas como produtoras dessas moléculas. Neste estudo é relatada pela primeira vez a presença de genes cyr em linhagens da América do Sul de C. raciborskii e a presença simultânea de genes cyr e sxt em uma única linhagem de C. raciborskii. Além disso, este é o primeiro estudo que relata a presença de genes envolvidos na biossíntese de MDN e MCA nas espécies de cianobactérias M. protocystis, M. panniformis e M. wesenbergii. Análises por espectrometria de massas acoplada a cromatografia líquida (LC-MS) e imunoensaio enzimático (ELISA) foram utilizadas a fim de detectar e identificar variantes estruturais das moléculas bioativas das cianobactérias que tiveram os genes biossintéticos sequenciados. A análise de LC-MS mostrou a produção das variantes GTX2, GTX3, STX e dc-STX pela linhagem C. raciborskii CENA302, enquanto que a linhagem C. raciborskii CENA305 apresentou as variantes NEO, C1 e dcGTX3. As quatro novas variantes de MCY, [D-Val1]MC-RR, [D-Leu/Ile1]MC-RR, [D-Leu/Ile1]MC-YR e [D-Phe1]MC-LR, foram encontradas nas espécies M. panniformis SPC702 e M. protocystis SPC697. Este é o primeiro relato da produção de MCY por essas duas espécies de Microcystis. Dezesseis linhagens que ainda não possuíam as sequências do gene de RNAr 16S foram sequenciadas. O resultado da análise filogenética das sequências do gene de RNAr 16S foi coerente com as descrições morfológicas, sendo que todas as linhagens foram caracterizadas em nível de espécie. As informações geradas neste estudo contribuem para o aumento do conhecimento da diversidade metabólica dos isolados brasileiros de cianobactérias e trazem nova visão sobre a evolução dessas moléculas produzidas pelo metabolismo secundário / The growing numbers of discoveries of bioactive substances produced by cyanobacterial secondary metabolism has attracted the interest of research groups around the world with the common goal of describing and exploring these molecules and understanding their biosynthesis. In Brazil, researches on bioactive molecules produced by native cyanobacterial strains are scarce. In this work, using specific PCR primers and sequencing, the presence of genes involved in the biosynthesis of the neurotoxin saxitoxin (STX) was confirmed in representatives of the genera Dolichospermum, Sphaerospermopsis, Cuspidothrix and Cylindrospermopsis, while genes of the cytotoxin cylindrospermopsin (CYN) were detected only in representatives of Cylindrospermopsis. Genes involved in the production of protease inhibitors, microviridin (MDN) and the cianobactin microciclamide (MCA), were sequenced in isolates of the genus Microcystis. The genomes of Cylindrospermopsis raciborskii strains CENA302 and CENA303 were sequenced using the high-throughput platform HiScan SQ (Illumina) as paired-ends 2 x 100 bp. The Sphaerospermopsis torques-reginae ITEP-024 genome was sequenced using the high-throughput platform Ion Torrent (Life Technologies) with fragment sizes up to 200 bp. Attempts of ab initio genomes assembly were performed and the 28 kb saxitoxin gene cluster of C. raciborskii strains CENA302 was identified and characterized. Phylogenetic analyses of amino acid sequences involved in the biosynthesis of the bioactive molecules evaluated showed that the Brazilian cyanobacterial isolates formed clades with high bootstrap values with homologous sequences of known cyanobacterial producers of these molecules. In this study is reported for the first time the presence of cyr genes in South America strains of C. raciborskii and the simultaneous presence of cyr and sxt genes in a single C. raciborskii strain. Furthermore, this is the first study reporting the presence of genes involved in the biosynthesis of MDN and MCA in the cyanobacterial species M. protocystis, M. panniformis e M. wesenbergii. Analyses by mass spectrometry coupled to liquid chromatography (LC-MS) and enzyme immunoassay (ELISA) were used to detect and identify structural variants of bioactive molecules of the cyanobacteria that had the biosynthetic genes sequenced. Analysis of LC-MS showed the production of the variants GTX2, GTX3, STX and dc-STX by the C. raciborskii strain CENA302, whereas the strain C. raciborskii CENA305 presented the variants NEO, C1 and dcGTX3. The new four MCY variants [D-Val1]MC-RR, [D-Leu/Ile1]MC-RR, [D-Leu/Ile1]MC-YR and [D-Phe1]MC-LR were found in the species M. panniformis SPC702 and M. protocystis SPC697. This is the first report of the MCY production by these two species of Microcystis. Sixteen strains that still lacked the 16S rRNA gene sequences were sequenced. The result of the phylogenetic analysis of 16S rRNA gene sequences was consistent with the morphological descriptions, and all strains were characterized to species level. The informations generated in this study contribute to the increase of knowledge on metabolic diversity of Brazilian cyanobacterial strains and bring new insight into the evolution of these molecules produced by secondary metabolism

Apesar da rápida expansão das aplicações da cromatografia líquida acoplada à espectrometria de massas em química clínica, a análise de metabólitos de baixo peso molecular e alta polaridade em matrizes biológicas ainda permanece como um grande desafio analítico. Dentre os compostos de grande importância no diagnóstico de doenças metabólicas que ainda carecem de melhores alternativas bioanalíticas destacam-se os aminoácidos. O presente estudo descreve o desenvolvimento e a validação de um novo método para a quantificação de 24 aminoácidos em plasma explorando a cromatografia líquida acoplada a espectrômetros de massas em tandem. Foi construído um método de detecção baseado em SRM (múltiplas reações selecionadas) com duas transições de massas para cada um dos 24 aminoácidos e os 19 padrões internos marcados com isótopos estáveis. Foram avaliadas três estratégias de separação cromatográfica e o melhor desempenho foi obtido com fase reversa com octadecilsilano (C18) com pareamento iônico com o ácido perfluoropentanoico. O método cromatográfico final permitiu a separação dos 24 aminoácidos, com resolução completa dos isômeros: leucina, isoleucina e allo-isoleucina, em 11 minutos incluindo o tempo de re-estabilização da coluna cromatográfica. Os limites de quantificação variaram em 113 fmol a 6 pmol injetados na coluna cromatográfica. A imprecisão obtida nos níveis testados para todos os aminoácidos foi inferior a 14%. O método apresentou linearidade para os intervalos testados chegando a 1,5 mmol.L-1 para vários compostos. Os ensaios de arraste mostraram que os limites máximos obtidos na linearidade não geram nenhuma interferência subsequente. A exatidão do método foi avaliada com amostras provenientes do programa de referência interlaboratorial European Research Network for evaluation and improvement of screening, Diagnosis and treatment of Inherited disorders of Metabolism (ERNDIM) e com o material de referência certificado do National Institute of Standards and Technology (NIST). Todos os analitos mostraram equivalência estatística com o método desenvolvido. / Despite the widespread use of liquid chromatography coupled to mass spectrometry applications in clinical chemistry, the analysis of low molecular weight and high polar metabolites in biological matrices remains as a major analytical challenge. Notwithstanding the key role played by amino acids in the diagnosis of metabolic diseases, there is still need for improvements in bioanalytical process of these analytes. The present study describes the development and validation of a new method for quantification of 24 amino acids in plasma based on liquid chromatography coupled to tandem mass spectrometry. Detection and quantification were achieved building a selected reaction monitoring method two mass transitions for each 24 amino acids and 19 stable isotope internal standards. Three chromatographic strategies for separation were evaluated, and best performance was achieved using reversed-phase octadecylsilane with perfluropentanoic acid as ion pairing agent. The separation method allowed separation of 24 amino acids with full resolution for isomers leucine, isoleucine and alloisoleucine in 11 minutes, including column equilibration time. The limits of quantification ranged from 113 fmol to 6 pmol (on column injection). Imprecisions for all evaluated levels and amino acids were less than 14%. The method is linear in all clinical intervals and extending up to 1.5 mmol.L-1. Carryover evaluation demonstrated absence of interference in the following injection throughout the analytical interval. Method accuracy was evaluated analyzing reference samples from European Research Network for evaluation and improvement of screening, Diagnosis and treatment of Inherited disorders of Metabolism (ERNDIM) and National Institute of Standards and Technology (NIST). Statistical equivalence was demonstrated for all analytes using the present method.

Les propriétés fonctionnelles de la protéine membranaire SLC5A8 et son rôle physiologique ont été étudiées in vitro et in vivo en utilisant des souris slc5a8-/-. In vitro, des mesures d’accumulation de métabolites par LC-MS sur des cellules HEK transfectées par SLC5A8 ont permis d’étudier ses capacités de transport de monocarboxylates sodium-dépendant (pyruvate mais aussi corps cétoniques). L’étude par analyse métabolomique a permis de montrer que l’uptake de pyruvate médié par SLC5A8 avait pour conséquences, outre l’alimentation énergétique du cycle de Krebs, un effet inhibiteur d’une enzyme glycolytique (GAPDH). Son dérivé halogéné (bromopyruvate), agent anti-tumoral ciblant la GAPDH, génère la même accumulation du substrat de la GAPDH. Nos résultats indiquent que le rôle proposé dans la littérature de suppresseur tumeur de SLC5A8 soit associé à un effet anti-Warburg. In vivo, les souris slc5a8-/- âgées présentaient un œdème intramyélinique diffus sans démyélinisation témoignant de désordres hydro-ioniques dans l’espace périaxonal par carence énergétique. Si l’expression tubulaire rénale de SLC5A8 a été confirmée, l’expression neuronale ne l’a pas été faisant envisager une origine rénale à la leucoencéphalopathie décrite. Les souris slc5a8-/- présentaient une fuite urinaire massive de corps cétoniques à l’origine d’une insuffisance cérébrale en β-hydroxybutyrate. Ce carburant est essentiel pour le cerveau, notamment en cas de dysfonction du métabolisme glucidique, comme l’insulinorésistance démontrée en deuxième partie de vie des souris slc5a8-/-. Cette étude illustre le rôle majeur des corps cétoniques en neuroénergétique. / The functional properties of the SLC5A8 membrane protein and its physiological role have been studied in vitro and in vivo using slc5a8-/- mice. In vitro, analysis of metabolite uptake by LC-MS with slc5a8 transfected HEK cells to study sodium-dependent transport of monocarboxylates, in particular pyruvate but also ketone bodies. Using a metabolomic approach, we showed that SLC5A8-mediated pyruvate uptake fuels the Krebs cycle and has an inhibitory effect on the glycolytic enzyme, GAPDH. Bromopyruvate, the halogen derivative of pyruvate, is a known antitumour agent targeting GAPDH and has a similar effect. We propose that the tumour suppressor function reported for SLC5A8 in the literature is associated with an "anti-Warburg" effect. In vivo, aged slc5a8-/- mice showed diffuse intramyelinic oedema without demyelination. This indicated a hydro-ionic disorder in the periaxonal space due to chronic energy deficiency. While expression of SLC5A8 was confirmed in renal tubular cells, the expression of the protein was not detected in brain suggesting a renal origin of the described leukoencephalopathy. Slc5a8-/- mice showed strong urinary loss of ketone bodies leading to cerebral insufficiency of β-hydroxybutyrate. This ketone is an essential energy source for the brain, in particular when carbohydrate metabolism is dysfunctionning, like in the case of insulin resistance that was found in aged slc5a8-/- mice. This study highlights the major role of ketone bodies in neuroenergetics.

Mitochondria are the main site of cellular adenosine triphosphate (ATP) generation which is achieved by a series of multi-subunit complexes and electron carriers which together create the oxidative phosphorylation system (OXPHOS). Whenever a defect in any of the numerous mitochondrial pathways occurs it is commonly referred to as a mitochondrial disorder. Mitochondrial disorders are a heterogeneous group of disorders characterised by impaired energy production and include a wide range of defects of either mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) encoded proteins. In cases of dysfunction in the respiratory chain (complex I to IV) it is known to be a respiratory chain deficiency (RCD) which presents a huge challenge for routine diagnosis largely due to the lack of a specific and sensitive biomarker(s). One sure way of confirming the suspicion of a RCD is by performing enzyme analysis on a muscle sample obtained through a biopsy. However, due to the lack of theatre time available to clinicians and the relative large number of false positive patients that are being selected for biopsies, it was decided to develop a biosignature to limit the number of false positive patients from the diagnostic workflow. An untargeted liquid chromatography mass spectrometry (LC-MS) metabolomics approach was used to investigate RCDs in children from South Africa. Sample preparation, a liquid chromatography time-of-flight mass spectrometry method and data processing methods were standardised. Furthermore the developed methodology made use of reverse phase chromatography in conjunction with positive electrospray ionisation (ESI) and a hydrophilic interaction chromatography (HILIC) in negative electrospray ionisation. Urine samples of 61 patients representing three different experimental groups were analysed. The three experimental groups comprised of patients with respiratory chain deficiencies, clinical referred controls (CRC) and patients suffering from various neuromuscular disorders (NMD). After a variety of data mining steps and statistical analysis a list of 12 features were compiled with the ability to distinguish between patients with RCDs and CRCs. The proposed signature was also tested on the neuromuscular disorder group, but this result indicated that the biosignature performed better when used to differentiate between patients with RCDs and CRCs, since the model was designed with this purpose. An alternative validation study is required to identify the features found with this proposed biosignature, to ensure that this biosignature can be practically implemented as a non-invasive screening method. / MSc (Chemistry), North-West University, Potchefstroom Campus, 2014