Orientador: Raquel Marques Braga / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-13T19:20:36Z (GMT). No. of bitstreams: 1 Silva_MariadoSocorroSousada_D.pdf: 6344706 bytes, checksum: 853a78239ffebd4d2b672cd61eb26a66 (MD5) Previous issue date: 2009 / Resumo: Nosso trabalho tem por objetivo o estudo dos alcalóides das espécies Amacrinum (híbrido Amaryllis x Crinum), Ismene festalis e três variedades de Amaryllis (¿sidney¿, ¿desire¿ e ¿belladonna¿) todas pertencentes a família Amaryllidaceae. As espécies desta família são fontes de alcalóides, e estes apresentam diversas atividades biológicas, entre elas a inibição da enzima acetilcolinesterase. O material utilizado nesse estudo (bulbos) foi adquirido de um produtor de plantas ornamentais da cidade de Holambra/SP. Os extratos EtOH e CH2Cl2 foram submetidos à extração ácido-base. Os extratos CHCl3 II de Amacrinum e Ismene festalis foram submetidos a purificações em cromatografia em coluna a pressão reduzida e cromatografia em camada semipreparativa e preparativa. Isolamos e identificamos nove alcalóides no extrato CHCl3 II de Amacrinum: beladina, N-desmetil-beladina, crinina, bufanidrina,1-O-acetil-licorina, 11-O-acetilambelina, undulatina, ambelina, bufanisina e dois alcalóides tazetina e haemantidina do extrato CHCl3 de I. festalis. Os extratos das três variedades de Amaryllis foram analisados por Cromatografia em fase Gasosa acoplada a Espectrometria de Massas (CG-EM), resultando na detecção dos alcalóides: montanina, hipeastrina, 1,2-diidro-clidantina, licorina e nerinina. Estes dados foram comparados aos obtidos em nosso estudo sobre Amacrinum e aos literários, permitindo-nos concluir que o híbrido Amacrinum possui em sua composição principalmente alcalóides que têm larga distribuição no gênero Crinum; sendo que undulatina e ambelina, também são observados na espécie A. belladonna. A avaliação qualitativa para inibição da acetilcolinesterase (AChE) por CCD (Métodos de Rhee e Marston) mostrou resultados positivos para o extrato CHCl3 de Amacrinum e para os alcalóides bufanisina, 1-O-acetil- licorina e undulatina. A avaliação quantitativa para inibição da AChE, pelo método colorimétrico baseado na metodologia de Rhee, mostrou que os alcalóides possuem IC50 maiores que os padrões galantamina e fisostigmina. A interação dos alcalóides fisostigmina, crinina e ambelina com a AChE foram avaliadas por RMN-H, onde observou-se que as interações mais fortes são com os hidrogênios aromáticos dos alcalóides / Abstract: The alkaloids from Amacrinum (a hybrid Amaryllis x Crinum), Ismene festalis and three varieties of Amaryllis (¿sidney¿, ¿desire¿, ¿belladonna¿) of the family Amaryllidaceae were isolated and characterized. The species of this family are sources of alkaloids with a wide range of interesting physiological effects, including inhibition of acetylcholinesterase. The bulbs were obtained in the city of Holambra, São Paulo, Brazil. The EtOH and CH2Cl2 extracts were submitted to acid-base extraction. The CHCl3 extracts of Amacrinum and Ismene festalis were submitted to repeated fractionation using flash-chromatography CC and preparative TLC on silica gel. We isolated and identified nine alkaloids in the CHCl3 extract of Amacrium: belladine, N-demethyl- belladine, crinine, buphanidrine, 1-O-acetyl-lycorine, 11-O-acetyl-ambelline, undulatine, ambelline, and buphanisine; and two alkaloids in the CHCl3 extract of I. festalis: tazetine and haemathidine. The extracts of the three varieties of Amaryllis were analyzed by gas chromatography coupled-mass spectrometry (GC-MS), resulting in detection of the alkaloids: montanine, hippeastrine, 1,2-dihydroclidantine, lycorine, and nerinine. Comparing these data with those obtained for the Amacrinum hybrid and literature data, we concluded that the Amacrinum hybrid contains mainly alkaloids that are widely distributed in the genus Crinum. The CHCl3 extract of Amacrinum and buphanisine, undulatine, and 1-O-acetyllycorine alkaloids showed a positive result for the evaluation of the inhibition of acetylcholinesterase by CCD (the Rhee and Marston method). The acetylcholinesterase inhibitory activity of the extracts and alkaloids of Amaryllidaceae was evaluated by the colorimetric method in a microplate reader. The majority of the extracts gave good results. The IC50 values for the Amacrinum alkaloids were lower that those determined for physostigmine and galanthamine. Interactions of physostigmine, crinine, and ambelline alkaloids with AChE were evaluated by RMN-H, which showed that the interactions were stronger with the aromatic hydrogens of alkaloids / Doutorado / Quimica Organica / Doutor em Ciencias Quimicas

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A importÃncia dos praguicidas como agente causal de intoxicaÃÃes e Ãbitos à evidenciado pelo nÃmero de ocorrÃncias registradas, principalmente nos paÃses em desenvolvimento. No Brasil, os praguicidas ocupam a terceira posiÃÃo dentre os agentes responsÃveis por intoxicaÃÃes agudas. Eles agem por inibiÃÃo enzimÃtica (acetilcolinesterase) de modo irreversÃvel, podendo provocar aparecimento de sinais e sintomas colinÃrgicos caracterÃsticos. Podem causar ainda o aparecimento da sÃndrome intermediÃria e da polineuropatia tardia. Este estudo teve como objetivos traÃar o perfil epidemiolÃgico dos pacientes intoxicados no estado do CearÃ, no perÃodo de fevereiro a julho de 2004, atendidos no Centro de AssistÃncia ToxicolÃgica do Cearà (CEATOX); avaliar o tratamento proposto; verificar os sinais e sintomas das sÃndromes colinÃrgica e intermediÃria e analisar os fatores de risco associados à evoluÃÃo dos pacientes. Foi realizado um levantamento de dados preliminares referentes a janeiro de 2002 atà junho de 2003. A coleta dos dados foi realizada a partir dos prontuÃrios mÃdicos, fichas de notificaÃÃo do CEATOX e entrevista com o paciente ou responsÃvel. Foram analisados 19 pacientes, sendo 10 (52,6%) do sexo masculino e 9 (47,4%) do feminino. A mÃdia de idade foi 27,8Â11,4 anos. A ocupaÃÃo trabalhador agrÃcola representou 42,1% (8/19). As tentativas de suicÃdio representaram 84,2% (16/19) dos casos. Houve 4 (21,1%) Ãbitos. As principais manifestaÃÃes clÃnicas foram diarrÃia (78,9%), miose (57,9%) e sialorrÃia(52,6%). Fez-se dosagem da AChE na admissÃo dos pacientes intoxicados, sendo mÃdia e desvio-padrÃo 1,06Â1,50 UI/mL. As demais dosagens foram feitas no decorrer do internamento de cada paciente. Dentre as complicaÃÃes clÃnicas, as do trato respiratÃrio foram as mais importantes (57,2%). Atropina foi administrada em 16 (84,2%) dos pacientes. A mÃdia de internaÃÃo foi 8,6Â8,5dias. Houve associaÃÃo estatÃstica quando se comparou ventilaÃÃo, tempo de UTI e tipo de intoxicaÃÃo com o surgimento de complicaÃÃes clÃnicas (p<0,05) (teste do qui-quadrado e exato de Fisher). A regressÃo logÃstica nÃo mostrou significÃncia estatÃstica quando analisou risco de Ãbito a partir das variÃveis em estudo. Os resultados mostraram que se faz necessÃrio uma reestruturaÃÃo no protocolo de atendimento e tratamento dos pacientes intoxicados com IOF, bem como sua divulgaÃÃo no hospital Instituto Dr. Josà Frota e em outras unidades hospitalares. Os resultados demonstram ainda a situaÃÃo crÃtica quanto ao uso inadequado de praguicidas organofosforados no estado do Cearà e a necessidade de orientaÃÃo ao consumidor e adequada vigilÃncia sanitÃria quanto ao uso e comercializaÃÃo dos mesmos. / The importance of the pesticides causal agent of intoxication and deaths is clearly shown by the number of registered cases, mainly in developed countries. In Brazil, pesticides places the third more important group of substances responsible for acute intoxication. They act through enzymatic inhibition (acetylcholinesterase) in an irreversible way, leading to characteristic cholinergic signs and symptoms. They are also able to cause the intermediary syndrome and the delayed polyneuropathy. This study aimed to set out the poisoning patientsâ epidemiological outline in Cearà state, observed from February to July 2004, who received medical care at Centro de AssistÃncia ToxicolÃgica do Cearà (CEATOX); evaluating the proposed treatment; verifying the signs and symptoms related to the cholinergic and intermediary syndromes; analyzing the risk factors matched to patients recovery. Some preliminary data were obtained from January 2002 to June 2003 concerning to these poisoning events. The data collection was performed from medical recording, CEATOX notification files and patients or their companion interviews. 19 patients were analyzed, 10 (52,6%) men and 9 (47,4%) women. The average age was 27,8  11,4. Agriculturists represented 42,1% (8/19) of all cases. Attempted suicide constituted 84,2% (16/19). There were 4 (21,1%) deaths. The main clinical observations were diarrhea (78,9%), myosis (57,9%) and sialorrhea (52,6%). The AChE levels were measured immediately after admission and expressed in terms of mean  standard deviation (1,06  1,50 UI/mL). The other AChE measurements were performanced during the permanence of the patients in the hospital. Among clinical complications, those ones related to the respiratory tract were the most relevant (57,2%). Atropine was administered to 16 (84,2%) patients. The average time of admission was 8,6  8,5 days. There was statistical association when were compared ventilation, time spent in the ICU and type of intoxication with clinical complications (p<0,05) (Chi-square test and Fisherâs test). The logistic regression did not show statistical differences when the death risk was analyzed comparing to the studied variables. The results stress the need to adopt more suitable measures with a restructured protocol in handling patients intoxicated with IOF, giving ample publicity at the hospital units of Dr. Josà Frota Institute and others. The data obtained also point out the critical situation in Cearà State in the use, misure or inappropriate vigilance by the sanitary authorities.

Este trabalho descreve a preparação, a caracterização e o uso de um biossensor de pasta de carbono modificado com a enzima acetilcolinesterase para a quantificação de carbamatos em alimentos, bem como o estudo das constantes de velocidade para a reação enzima/substrato (iodeto de acetiltiocolina) em solução. Inicialmente foram realizados testes de estabilidade, tanto para o substrato quanto para a enzima. Nestes testes, a absorção na região do UV-vis do substrato não apresentou diminuição significativa em 11 dias de análises, já a enzima apresentou uma grande perda de sua atividade com apenas três dias de preparo da solução. Na preparação do eletrodo de trabalho alguns parâmetros foram otimizados, tais como: quantidade de enzima e de ftalocianina de cobalto (CoPC) no eletrodo, bem como a porcentagem de glutaraldeído utilizada. A melhor resposta ocorreu para adição de 2,40x10-3g de enzima, 0,90x10-3g de CoPC (referentes à massa de 0,017g de pasta de carbono) e solução de glutaraldeido 1%. A seguir, realizou-se um experimento baseado na inibição da atividade da enzima, causada pela imersão do eletrodo na solução contendo o pesticida carbaril nas concentrações 5,00x10-5 e 1,00x10-4 mol L-1. Notou-se que, com o aumento da concentração do carbaril, houve aumento na inibição da atividade enzimática. Desta forma o eletrodo apresentou-se apto para determinação analítica de pesticidas. Estas medidas foram realizadas em meio de tampão fosfato 0,1 mol L-1, pH 7,4 e com tempo de incubação para o carbaril, metomil e aldicarbe foram de 8, 12 e 15 minutos, respectivamente. Os limites de detecção (LD) e quantificação (LQ) obtidos utilizando-se o biossensor amperométrico para o carbaril foram de 2,00x10-6 mol L-1 (0,40 mg L-1) e 6,70 x 10-6 mol L-1 (1,30 mg L-1), para o metomil de 1,88 x 10-7mol L-1 (30,45 micro g L-1) e 6,26 x 10-7 mol L-1 (0,10 mg / L-1) e para o aldicarbe de 1,10x10-6 mol L-1 (0,20 mg L-1) e 3,60x10-6 mol L-1 (0,70 mg L-1). Para a formulação comercial Lannate (metomil) os LD e LQ foram 2,13x10-7 mol L-1 (34,50 micro g L-1) e 7,09x10-7 mol L-1(0,12 mg L-1), respectivamente. As medidas de HPLC apresentaram LD e LQ de 1,58 x 10-8 mol L-1 (3,18 micro g L-1) e 5,27x10-8 mol L-1 (10,60 micro g L-1) para o carbaril e de 9,02 x 10-10 mol L-1 (0,15 micro g L-1) e 3,00 x 10-9 mol L-1 (48,60 micro g L-1) para o metomil. Testes de recuperação foram realizados usando ambas as técnicas para o carbaril e Lannate. As recuperações utilizando-se o biossensor mostraram-se eficientes, variando de 76,83 a 106,67% para o carbaril e de 78,00 a 96,50% para a Lannate, enquanto que nas medidas de HPLC, as recuperações foram de 78,00 a 108,33% para o carbaril e de 57,00 a 99,50% para o Lannate. A recuperação para o aldicarbe no tomate foi de 62,40 %. As análises da enzima em solução mostraram que a metodologia empregada neste estudo é adequada para a determinação das constantes de velocidade para a etapa lenta da reação AchE/AchI. Observou-se que os valores destas constantes são dependentes da concentração dos pesticidas fenitrothion (organofosforado) e carbaril (carbamato), em baixa concentração ambos apresentaram constantes de velocidade similares, mas com o aumento dessa concentração, o fenitrothion apresentou menor constante de velocidade em relação ao carbaril, sugerindo que este apresenta maior inibição da enzima e por conseqüência maior toxicidade no organismo. Esses resultados mostraram uma possível metodologia analítica para a quantificação destes pesticidas, obtendo-se os valores das constantes de velocidade enzimática e suas dependências com as concentrações dos pesticidas em solução. / This work describes the development, characterization and utilization of a carbon paste biosensor based in the acetylcholinesterase enzyme for carbamates determinations in foodstuff, as well as the study of rate constants for enzyme/substrate reaction in solution. Stability tests were initially performed for both the substrate and the enzyme. In these tests, the signal for UV-vis adsorption for the substrate shows no inhibition during 11 days while for the enzyme it has been demonstrated that a considerable loss of activity occurs after three days from the solution preparation. In the electrode preparation, some experimental parameters were optimized, such as the amount of enzyme and the content of cobalt ftalocyanine (CoPC) in the electrode, as well as the employed percentage of glutaraldehide. The highest analytical signals were obtained for the addition of 2.40x10-3 g enzyme, 0.90x10-3 g CoPC (related to the massa of 0,017g of carbon paste) and a 1% glutaraldehide solution. The next step was to carry out an experiment based in the inhibition of enzyme activity by the pesticide. For this, the biosensor was immersed in 5.00x10-5 e 1.00x10-4 mol L-1 carbaryl solutions. It was observed that, by increasing the carbaryl concentration, the electrochemical signal of the sensor was inhibited proportionally. This was indicative that the sensor was adequate to be used in carbaryl monitoring and analytical determinations. The analytical determinations of carbamate pesticides were performed in 0.1 mol L-1 phosphate buffer, pH 7,4, with incubation time of 8, 12 and 15 minutes for carbaryl, metomil and aldicarb, respectively. The detection (LD) and quantification (LQ) limits obtained with the biosensor were 2.00x10-6 mol L-1 (0.40 mg L-1) and 6.70 x 10-6 mol L-1 (1.30 mg L-1) for carbaryl, 1.88x10-7mol L-1 (30.45 micro g L-1) and 6.26x10-7 mol L-1 (0.10 mg / L-1) for metomil and 1.10x10-6 mol L-1 (0.20 mg L-1) and 3.60x10-6 mol L-1 (0.70 mg L-1) for aldicarb. For the commercial formulation of metomil, Lannate, LD and LQ obtained were 2.13x10-7 mol L-1 (34.50 microg L-1) and 7.09x10-7 mol L-1(0.12 mg L-1), respectively. The HPLC measurements showed LD and LQ of 1.58x10-8 mol L-1 (3.18micro g L-1) and 5.27x10-8 mol L-1 (10.60 micro g L-1) for carbaryl and 9.02x10-10 mol L-1 (0.15 micro g L-1) and 3.00x10-9 mol L-1 (48.60 micro g L-1) for metomil. Recovering tests were also done with both analytical techniques for carbaryl and Lannate. The obtained recoveries using the biosensor were in the range of 76.83 to 106.67% for carbaryl and 78.00 to 96.50% for Lannate, while using the HPLC, the recoverings were 78.00 a 108.33% for carbaryl and 57.00 to 99.50% for Lannate. The recovering of aldicarb in tomatoes, with HPLC, were 62.40 %. The study of the enzymatic reaction in solution showed that the employed methodology allows to obtain the rate constant values for the rate determining step of the AchE/AchI reaction. It was observed that these rate constant values were strongly dependent in the pesticide concentrations for fenitrothion (organofosforous) and carbaryl (carbamate). At low concentration levels of the pesticide in the electrolyte, all the rate constants showed similar values but, when the pesticide concentration was raised, fenitrothion was found to exert a more powerful inhibition action for the enzyme activity than carbaryl, thus suggesting its higher toxic character. These results showed the development of a possible analytical methodology for quantification of these pesticides, by calculating the rate constant value and its dependence to the pesticide concentration in solution.

A doença de Alzheimer é uma afecção crônica degenerativa que não possui tratamento até o momento. O uso de alimentos funcionais como a romã na prevenção e/ou tratamento de doenças neurodegenerativas têm sido amplamente pesquisados. Diante disto, o presente trabalho teve como objetivo avaliar a quantidade de compostos bioativos (antocianinas, compostos fenólicos e flavonoides), atividade anticolinesterásica e a capacidade antioxidante in vitro e on line dos extratos de polpa e casca de romã e posteriormente estudar o possível efeito neuroprotetor de micropartículas obtidas a partir do extrato da casca de romã em um animal submetido a infusão crônica de peptídeo &beta;-amilóide. O extrato de casca de romã apresentou maior teor de antocianinas, compostos fenólicos, flavonoides e atividade antioxidante in vitro e on line do que o extrato da polpa. Na análise de compostos não voláteis pela técnica de GC-MS foram identificados 38 compostos no extrato da casca e 37 da polpa de romã, sendo o ácido gálico a principal substância detectada. Foram encontrados no total 13 compostos no extrato de casca e 8 no extrato de polpa de romã que apresentaram atividade antioxidante pelo método HPLC-ABTS on line. A punicalagina, epicatequina e ácido gálico foram os compostos determinantes para a atividade antioxidante em ambos os extratos. O extrato da casca de romã apresentou atividade anticolinesterásica superior ao da polpa. Estes resultados, em conjunto, indicaram um possível potencial da casca de romã como um agente neuroprotetor na doença de Alzheimer. Para estudar o possível efeito neuroprotetor do extrato da casca de romã foram utilizados camundongos C57BL/6 cronicamente infundidos com peptídeo &beta;A1-42 e/ou veículo através de mini-bombas osmóticas durante 35 dias e foram avaliados biomarcadores e alterações comportamentais. Micropartículas de extrato de casca de romã, produzidas em spray dryer, foram diluídas em água e administradas na dose de 800 mg de casca de romã/kg de animal/dia. A memória espacial foi avaliada em labirinto de Barnes e uma redução no número de erros para encontrar a caixa de escape foi verificada nos animais tratados com micropartículas de casca de romã e nos animais do grupo controle, mas não nos animais do grupo &beta;A. A atividade da acetilcolinesterase, neurotrofina BDNF, TNF-&alpha; e a enzima SOD foram avaliadas no hipocampo, córtex e soro dos animais. A peroxidação lipídica foi avaliada no fígado dos animais. Como a casca de romã não é comumente consumida foram dosados marcadores de dano isquêmico hepático. O consumo de micropartículas de casca de romã promoveu uma redução do acumulo de placas amiloides, aumento da expressão de neurotrofinas, redução da atividade da enzima acetilcolinesterase, redução da peroxidação lipídica e da citocina pró-inflamatória TNF-&alpha; em animais infundidos com peptídeo &beta;-amilóide. O consumo das microcáspulas de casca de romã não acarretou nenhum tipo de lesão hepática. No geral, verificou-se que os compostos presentes na casca de romã podem apresentar um efeito neuroprotetor em animais submetidos a infusão crônica de peptídeo &beta;-amilóide. / Alzheimer\'s disease is a chronic and degenerative condition that have no treatment until now. The research of functional foods such as pomegranate for the prevention and/or treatment of many conditions, including neurodegenerative diseases, is increasing year after year. The amount of bioactive compounds (anthocyanins, phenolic compounds and flavonoids), acetylcholinesterase activity and antioxidant capacity in vitro and on line of pomegranate peel and pulp extracts were evaluated. Pomegranate peel extract has higher content of anthocyanins, phenolic compounds, flavonoids and antioxidant activity in vitro and on line than pulp. The analyses of the profile of non-volatile compounds identified 38 compounds in the peel and 37 in the pulp. The gallic acid was main compound detected. Pomegranate peel showed 13 compounds with antioxidant activity by the HPLC-ABTS method online and pulp showed eight compounds. Punicalagin, Gallic acid and epicatechin were determinants for the antioxidant capacity of the aqueous-alcoholic extract of pomegranate. Pomegranate peel extract had greater anticholinesterase activity than pulp. These results together indicated a possible potential of pomegranate peel as a neuroprotective agent in Alzheimer\'s disease. This research had as objective to study the possible neuroprotective effect of pomegranate peel on an animal model of the Alzheimer\'s disease. For that purpose, mice model of Alzheimer\'s disease were used and biomarkers and behavioral changes were evaluated. C57BL/6 mice were chronically infused with &beta;A1-42 peptide and/or vehicle by mini - osmotic pumps during 35 days. Microparticles of pomegranate peel extract, produced by spray drying, were diluted in water and administered at a dose of 800 mg of pomegranate peel/ kg animal/day. The spatial memory was evaluated in the Barnes maze and a reduction of the errors to find the scape box was verified in animals treated with the PPE, as observed in the Control group, but not in th A&beta; group. The activity of acetylcholinesterase, neurotrophin BDNF, TNF-&alpha; and SOD were measured in the hippocampus, cortex and serum. Lipid peroxidation was evaluated in the liver. As the pomegranate peel is not commonly consumed, biomarkers of liver ischemic damage were measured. Pomegranate peel consumption promoted a reduction of amyloid plaques, increasing neurotrophin expression, reduction in a AChE activity, reduced lipid peroxidation and reduced TNF-&alpha; in animal models of Alzheimer\'s disease. The consumption of pomegranate peel did not cause liver injury. In general, pomegranate peel showed a neuroprotective effect on animal models of the Alzheimer\'s disease.

O desenvolvimento na área agroquímica associado as novas técnicas de plantio, asseguram ao país recordes anuais na produção agrícola. Entretanto, os defensivos agrícolas e fertilizantes utilizados para aumentar a produção das lavouras não são inertes a saúde humana. Exposições contínuas e inadequadas a esses compostos químicos podem causar sua absorção e resultar em intoxicações agudas ou crônicas. Com o objetivo de avaliar essas exposições, dosamos a atividade da enzima acetilcolinesterase, assim como, avaliamos os hemogramas e dosamos os níveis sanguíneos dos metais arsênio (As), cádmio (Cd), chumbo (Pb), manganês (Mn), zinco (Zn), cobre (Cu) e o não metal selênio (Se) em trabalhadores rurais e moradores da área urbana da região de Rio Verde-GO e comparamos esses resultados. A atividade média da enzima colinesterase eritrocitária nos trabalhadores rurais apresentou uma depressão significativa indicando uma exposição inadequada aos inseticidas inibidores das colinesterases. As concentrações sanguíneas médias dos metais As, Cd, Mn, e Zn nos trabalhadores rurais são maiores do que na população urbana, indicando que as exposições inadequadas aos fertilizantes e defensivos agrícolas podem causar absorção desses metais. A concentração sanguínea média de Se na população urbana é maior do que nos trabalhadores agrícolas. Esse fato pode estar ligado a alimentação, sendo que, uma provável causa seria o baixo consumo de alimentos ricos em selênio (castanha-do-pará, salmão, farelo de trigo, ostras e fígado bovino). Os hemogramas não apresentaram alterações, indicando que, sua utilização isolada na monitorização das exposições ocupacionais aos defensivos agrícolas e fertilizantes é inadequada. / Advancements in the agrochemical industry associated with new seeding techniques make it possible for the country to reach annual crop records in production. However, the chemicals and fertilizers used for increasing productions are by no means harmless to human health. Repeated and inadequate exposures to such chemicals may result in their absorption and cause acute and chronic poisoning. In order to assess these exposures, we measured the activity of the acetylcholinesterase enzyme and evaluated hemograms. In addition, we measured blood levels of metals such as arsine (As), cadmium (Cd), lead (Pb), manganese (Mn), zinc (Zn), copper (Cu), and the non metallic selenium in farm workers and urban residents in a region of Rio Verde- GO- Brazil and compared the results. Mean activity of the erythrocyte cholinesterase enzyme in the rural workers presented a significant decrease, indicative of inadequate exposure to cholinesterase inhibiting insecticides. Mean concentrations of the metals As, Cd, Mn, and Zn were higher in rural workers compared to urban residents, which suggests that inadequate exposure to fertilizers and agricultural chemicals may result in their absorption. Mean blood concentration of Se in urban residents was higher compared to rural workers. That can be associated with diet and a possible cause may be a low consumption of high Se foods (Brazils nuts, salmon, oysters, wheat bran, and bovine liver). The hemograms did not present any changes, indicating that its use for monitoring occupational exposures to fertilizers and agricultural chemicals is inadequate.

Orientador: Wanda Pereira Almeida / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-24T01:24:55Z (GMT). No. of bitstreams: 1 Silva_GiseleSilvestreda_M.pdf: 8524593 bytes, checksum: e3f6789232b8b6dc82852428db406fbf (MD5) Previous issue date: 2013 / Resumo: A Doença de Alzheimer (DA) é uma doença neurodegenerativa, que compromete as funções cognitivas. A acetilcolinesterase (AChE), enzima responsável pela hidrólise da acetilcolina (ACh), é um importante alvo para o desenvolvimento de candidatos a fármacos para tratar a DA. A AChE possui dois sítios ligantes: o catalítico e o periférico, envolvidos com a hidrólise da AChE e com o processo de formação de fibrilas do peptídeo b-amilóide, respectivamente. Neste trabalho propusemos a síntese e avaliação biológica de dois híbridos, ambos contendo porção tetraidroacridina baseado na estrutura da tacrina O hibrido I contem uma subunidade indanona baseado na donepezila e o híbrido II contém uma porção anti-inflamatória do ibuprofeno. O híbrido I e o híbrido II comportaram-se como um simples ligante e um híbrido molecular multipotente, respectivamente. Em ambos os casos foram escolhidos híbridos contendo duas unidades metilênicas. Um intermediário tetraidroacridínico contendo um grupo aminoálcool (6), que também se liga ao sítio catalítico da AChE, foi sintetizado a partir do ácido antranílico em uma sequência de três etapas. Todas as tentativas de acoplar este intermediário ao ibuprofeno fracassaram. Face a estes resultados, voltamos nossa atenção para as quinolonas, compostos planares que como a tacrina poderiam interagir com o sítio catalítico da AChE. Assim, nós sintetizamos quatro derivados da 4-quinolona. A síntese envolveu a ciclização catalisada por TFA do aduto de Morita-Baylis-Hillman, derivado do 2-nitrobenzaldeído, levando ao correspondente N-óxido (32). Em seguida, ele foi tratado com hexacarbonilmolibdato para fornecer a 3- carboetoxi-4-quinolona (38) em 33 % de rendimento global. O ácido carboxílico correspondente e derivados N-etilados também foram preparados. O efeito de três destes derivados quinolônicos sobre a atividade da acetilcolinesterase foi estudado. A N-alquil-3- carboetoxi-4-quinolona (40) foi o mais ativo dos derivados (IC50 ~84mmol/L). Estudo de docking molecular corroboraram nossas observações / Abstract: AlzheimerLs disease (AD) is a neurodegenerative pathology, which compromises the cognitive functions. Acetylcholinesterase (AChE) is the enzyme involved in the hydrolysis of neurotransmitter acetylcholine (ACh) and has been highlighted as an important target for the design of drugs to treat AD. AChE has two binding sites: a catalytic site and the peripheral one, which are involved in the acetylcholine hydrolysis and the formation of Ab42 peptide fibrils, respectively. In this work we proposed the synthesis and biological evaluation of two hybrids based on the tacrine structure, both containing portion tetrahydroacridine based on the structure of tacrine. The hybrid I has donepezil moieties and the hybrid II has anti-inflammatory portion. The hybrid I and hybrid II behave as a simple ligand and molecular hybrid, respectively. We have found that linkers with two and three methylene units generate suitable hybrids to bind to the catalytic site of the AChE. A key tetrahydroacridine bearing an amino alcohol function (6) also binds to the catalytic site of the AChE. It was synthesized from anthranilic acid in three steps sequence. All attempts to couple 6 and ibuprofen failed. In view of these results, we turn our attention to other planar structures which could interact with the catalytic site of the AChE. Thus, we synthesized four 4-quinolone derivatives. The synthesis involved a TFA mediated cyclization of the Morita-Baylis-Hillman adduct, derived from 2-nitrobenzaldehyde, leading to the corresponding N-Oxide (32). Then, it was treated with hexacarbonyl molibdate to afford 3-carboethoxy-4-quinolone (38) in 33% overall yield. We have also prepared: the corresponding carboxylic acid and the N-ethyl derivatives. The effect of three of them on the acetylcholinesterase activity was evaluated. The N-alkyl-3-carboethoxy-4- quinolone (40) was the most active (IC50 ~84mmol/L). Molecular docking studies corroborated our observations / Mestrado / Quimica Organica / Mestra em Química

Magister Pharmaceuticae - MPharm / Alzheimer's disease is a progressive neurodegenerative disease characterised by low acetylcholine (ACh) levels in the hippocampus and cortex of the brain, causing symptoms like progressive memory loss, decline in language skills and other cognitive impairments to occur. The hallmarks of AD include the presence of extracellular insoluble amyloid beta plaques, intracellular neurofibrillary tangles, and the decrease in ACh concentration. The pathophysiology of AD is not well understood, however, acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and monoamine oxidases (MAO) are conspicuous role players in AD pathogenesis. Based on the cholinergic hypothesis, the AChE inhibitor donepezil was developed and has been used effectively clinically in the management of AD, with minimal side effects. Studies regarding the binding interactions of donepezil with AChE has shown that the benzyl-piperidine moiety of this compound shows substantial binding interactions at the CAS site of AChE where it blocks AChE activity. Coumarin is a compound of natural source that has shown some MAO inhibitory activity. Further studies done to clarify the potential of coumarin as a drug against AD has shown that coumarin has the capacity to bind at the PAS site of AChE, thus giving it the potential to prevent AChE induced amyloid plaque formation. Due to the multifactorial nature of AD, the drugs in the market show limited therapeutic benefits and are mainly for symptomatic relief. In order to address this limitation in AD treatment, researchers are exploring the possibility of designing a multi-target-directed-ligand (MTDL). The aim of this study was to synthesise a series of compounds out of pharmacophoric groups of donepezil and coumarin that will be able to inhibit both cholinesterases and MAO B. Four series of 5 compounds per series were synthesised. The first series of compounds consisted of the coumarin moiety to which a 1,4-dibromo benzene moiety was attached. The second series represented the coumarin moiety to which a piperidine (donepezil moiety shown to confer cholinesterase inhibitory property) was attached. The third series represented the coumarin moiety to which bromobenzyl-piperazine was attached and in the last series were compounds similar in structure to series 1 with an unsubstituted benzyl moiety as opposed to the dibromobenzyl moiety. Prior to the synthesis, molecular modelling was conducted in order to have an idea of the binding capacity of the compounds to MAO A and B and cholinesterases. In vitro biological evaluation of the compounds was done and used to determine the IC₅₀ values of the compounds. Nineteen compounds were synthesised and purified successfully as shown by their NMR, MS and IR spectra. The compounds to which dual inhibitory activity was conferred were those in series 2 and 3, of which series 2 showed the best overall inhibitory activity with IC₅₀ values within the low μM range. The compound with the best overall activity was Cp 9. Molecular modelling of Cp 9 showed that the coumarin core was located in the PAS region of AChE while the benzyl-piperidine moiety was situated in the CAS region of the enzyme. This compound orientation demonstrates the potential of Cp 9 to inhibit AChE induced amyloid beta plaque formation. Cp 9 showed no inhibitory activity towards MAO A, but showed good inhibitory activity towards MAO B with an IC₅₀ value of 0.30 μM. Its inhibitory activity towards cholinesterases also fell within the low μM range (AChE IC50 = 9.1 μM and BuChE IC₅₀ = 5.9 μM). From the results, it can be concluded that Cp 9 was able to inhibit both cholinesterase and MAO B catalytic activities at low μM concentrations. This thus means that our novel compound will not only increase ACh levels in the brain thus improving cognitive activity, but it will also have neuroprotective effect from its MAO B inhibitory property and also potentially slow down amyloid plaque formation due to AChE activity. / National Research Foundation (NRF)

>Magister Scientiae - MSc / Alzheimer’s Disease (AD) is a neurodegenerative disease which results from the irreversible loss of neurons in the brain. The disease is characterized by progressive cognitive impairment with recurrent short-term memory loss. AD is the leading cause of dementia and 4th leading cause of death in the elderly. Success in the treatment of AD has been limited, with drugs only treating it at a symptomatic level due to its pathology being complex and poorly understood. However, it is known that the cholinesterase and MAO-B enzymes play an important role in the disease through their association with production of amyloid plaques and oxidative stress respectively, two mechanisms associated with cell death and the symptoms seen in AD.

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Ondrej Tomáš Supervisor: PharmDr. Marie Vopršalová, CSc. Consultant supervisor: mjr. PharmDr. Vendula Hepnarová, Ph.D. Title of diploma thesis: Evaluation of newly prepared insecticides in vitro Malaria is a widespread infection and one of the most dangerous diseases transmitted by insects. It threatens lives of millions of people all around the world, thus its regulation is necessary. Most common malaria vectors are mosquitoes of genus Anopheles. Novel structures of insecticides with selective inhibition of mosquito acetylcholinesterase are subjects of research, with an intention to deal with this problem. The aim of this work was to test six newly prepared succinimide derivatives with insecticidal potential. The ability of these compounds to inhibit Anopheles gambiae mosquito (AgAChE) and human acetylcholinesterase (hAChE) was evaluated. Leading structures of these compounds were also tested to find relations between chemical structure and biological activity. The modified Ellman's method was used to obtain the half maximal inhibitory concentration (IC50) values for both enzymes. Tested substances were able to inhibit only hAChE and none of them displayed activity against AgAChE. Compound...

Neurodegenerative diseases occur as a result of the breakdown and deterioration of the neurons of the central nervous system (CNS). They are commonly found in elderly people and are a major cause of morbidity and mortality, thereby imposing severe strains on the social welfare systems. Alzheimer’s disease (AD) is the most common age-related neurodegenerative disorder. Cholinergic deficit, senile plaque/amyloid-β peptide deposition and oxidative stress have been identified as three main pathogenic pathways which contribute to the progression of AD. The current therapeutic options cause several side-effects and have problems associated with bioavailability. Therefore, the need arises to search for new compounds from natural products with potential to treat AD. Seventeen plants were selected for this study based on their documented ethno-medicinal use in improving memory, to treat insomnia, calm agitated people, and other neurological disorders. The plants were screened for inhibition of acetylcholinesterase (AChE) using the TLC and microtiter plate method. A dose-dependent inhibition of the enzyme was observed and 4.5% of all the plants showed low (<30% inhibition) AChE inhibition. The ethyl acetate extracts of the roots of Crinum bulbispermum, Xysmalobium undulatum, Lannea schweinfurthii, Scadoxus puniceus and bulbs of Boophane disticha had the best AChE inhibition. Although the IC50 of these plant extracts were higher than that of the positive control, galanthamine (0.00053 mg/ml), they showed good AChE inhibitory activity considering they are still mixtures containing various compounds. The antioxidant activity of the plant extracts was determined by their ability to scavenge ABTS (2,2´-azinobis-3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (1,1-diphenyl-2-picryl- hydrazyl) radicals. The dichloromethane/methanol (1:1) extracts of Chamaecrista mimosoides (root), Buddleja salviifolia (whole plant), Schotia brachypetala (root and bark), water extracts of Chamaecrista mimosoides (root), Buddleja salviifolia (whole plant), Schotia brachypetala (root and bark) and methanol extracts of the roots of Crinum bulbispermum, Piper capense, Terminalia sericea, Lannea schweinfurthii and Ziziphus mucronata all showed good antioxidant activity (>50%), in both assays. B. disticha contained very promising AChE inhibition and was subjected to isolation of active compounds using thin layer chromatography, column chromatography and preparative thin layer chromatography. Two compounds, 6-hydroxycrinamine (a crinine-type alkaloid) and cycloeucalenol (a cycloartane triterpene), were isolated for the first time from the bulbs of this plant. 6-Hydroxycrinamine, and two fractions, EAM 17-21 21,22 and EAE 11 (which could not be purified further due to low yield), were found to inhibit AChE with IC50 values of 0.445 ± 0.030 mM, 0.067 ± 0.005 mg/ml and 0.122 ± 0.013 mg/ml, respectively. Cytotoxicity of the isolated compounds and two active fractions was determined on human neuroblastoma (SH-SY5Y) cells using the MTT and neutral red uptake assays. 6- hydroxycrinamine and fraction EAM 17-21 21,22 were found to be toxic with IC50 values of 54.5 μM and 21.5 μg/ml as determined by the MTT assay. The isolated compounds and fractions did not show any protective effect against cell death induced by Aβ25-35 possibly due to the poor antioxidant activity of B. disticha bulbs. Cytotoxicity was also determined for the methanol extracts of the roots of C. bulbispermum, T. sericea, L. schweinfurthii and Z. mucronata, as they contained promising antioxidant activity. C. bulbispermum was the most toxic, reducing cell viability by <40% at the highest concentration tested. Z. mucronata and L. schweinfurthii were the least toxic with IC50 values exceeding 100 μg/ml, the highest concentration tested. Three concentrations of the plant extracts that were not toxic, or presented low toxicity, were selected to evaluate their possible protective effect against cell death induced by Aβ25-35. Pretreatment with Z. mucronata and T. sericea roots showed a dose dependent inhibition of cell death caused by Aβ25-35. Pre-treatment with L. schweinfurthii roots resulted in an optimum dose for inhibition of Aβ25-35 induced cell death at 25 μg/ml, while still maintaining 80% viability. The roots of C. bulbispermum at non-toxic dose still maintained >50% viability. This study confirms the neuroprotective potential of some of the plants which had AChE inhibitory and antioxidant activity. In addition, four of the plants were shown to prevent cell death caused by Aβ25-35. These plants can serve as potential leads in developing drugs relevant to treatment of AD. Furthermore, two new compounds present in the bulbs of B. disticha were identified. Additional investigations need to be carried out by applying QSAR studies to modify the structure of the alkaloid with the aim of reducing its observed toxicity. / Thesis (PhD)--University of Pretoria, 2012. / Pharmacology / unrestricted