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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Sintese e avalia??o de atividade tripanocida de novos heterociclos da classe dos 1,2,4-OXADIAZ?IS, derivados e an?logos da amida natural piperina. / SYNTHESIS AND EVALUATION OF TRIPANOCIDAL ACTIVITY OF NEW HETEROCYCLES OF THE 1,2,4-OXADIAZIAL CLASS, DERIVATIVES AND ANALOGS OF THE NATURAL AMID PIPERINA.

Soares, Breno Almeida 25 September 2009 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-08-29T14:02:13Z No. of bitstreams: 1 2009 - Breno Almeida Soares.pdf: 7105040 bytes, checksum: 3b6aebf34151816545510b0506ed3412 (MD5) / Made available in DSpace on 2017-08-29T14:02:13Z (GMT). No. of bitstreams: 1 2009 - Breno Almeida Soares.pdf: 7105040 bytes, checksum: 3b6aebf34151816545510b0506ed3412 (MD5) Previous issue date: 2009-09-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior, CAPES, Brasil. / This work is part of a research project which investigates the utilization of abundant and accessible natural products in the synthesis of new molecules with potential activity against Chagas? disease. Recent studies carried out in our laboratory showed activity against Trypanosoma cruzi for piperine, a major component of Piper nigrum and for a series of its derivatives and analogues. Using bioisosterism as a strategy for molecular modification, we describe here the design, synthesis and antiparasitic evaluation of class of derivatives of 1,2,4-oxadiazole. The key step of the synthetic strategy used involved the SNAC reaction of the benzamidoxima with acid chlorides followed by cyclization, which allowed the preparation of eight new 1,2,4-oxadiazole The evaluation of the toxic activity of these new derivatives against epimastigote form of T. cruzi confirmed the bioisosteric relationship between the natural amide and the new products prepared, showing the oxadiazole 55 direct derived from piperine, as the most active compound in the series. / Este trabalho se insere numa linha de pesquisa que visa a utiliza??o de produtos naturais abundantes e access?veis na s?ntese de novas mol?culas com potencial atividade anti-chag?sica. Estudos recentes em nosso laborat?rio demonstraram a atividade antiparasit?ria da piperina e de uma s?rie de derivados e an?logos sobre o Trypanosoma cruzi, agente etiol?gico da doen?a de Chagas. Utilizando o bioisosterismo como estrat?gia de modifica??o molecular, descrevemos aqui o planejamento, a s?ntese e a avalia??o antiparasit?ria de derivados da classe dos 1,2,4-oxadiaz?is. A etapa-chave da estrat?gia sint?tica utilizada envolveu a rea??o de SNAC da benzamidoxima com cloretos de ?cidos, seguida de cicliza??o, que permitiu a prepara??o de oito novos 1,2,4- oxadiaz?is. A avalia??o da atividade t?xica destes novos derivados contra a forma epimastigota do T. cruzi confirmou a rela??o bioisost?rica entre a amida natural e os novos derivados preparados, evidenciando o oxadiazol 55 derivado direto da piperina, como o composto mais ativo da s?rie.
2

Avalia??o de antiparasit?rios sobre o perfil enzim?tico e exame androl?gico em Nelore. / Anti-parasitic evaluation on the enzymatic profile and andrologic exam in Nelore.

Almeida, Jaci de 10 December 2010 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2018-04-11T16:32:51Z No. of bitstreams: 1 2010 - Jaci de Almeida.pdf: 1762363 bytes, checksum: 6b47b0e954a40b42efe066ff6875b0af (MD5) / Made available in DSpace on 2018-04-11T16:32:51Z (GMT). No. of bitstreams: 1 2010 - Jaci de Almeida.pdf: 1762363 bytes, checksum: 6b47b0e954a40b42efe066ff6875b0af (MD5) Previous issue date: 2010-12-10 / Ectoparasite affects in the animals, carrying great prejudices to the health and considerable economic losses. Antiparasitic utilization of wide action spectrum has been assisting in the losses reduction in consequence of these infestations. They were objectives of this work, evaluate of the treatment antiparasitic effects, in therapeutic doses, in the preventive control of the natural infestations for Dermatobia hominis and Haematobia irritans, and about the andrological characteristics, enzymatic profile (AST and ALT) and her correlations in Nelore bulls seminal caracteristics. They were used 20 bulls from 24 to 30 age months, managed in grazing system (Brachiaria decumbens and B. brizantha). The experiment was executed in completely randomized design with four treatments (T1 = Control, without medication; T2 = Ivermectina injet?vel to 3,15%; T3 = Fipronil ?pour-on? e T4 = Doramectina to 1%), three applications (0, 60 and 120 days), five repetitions (bulls) and five semen collections (D0, D15, D30, D45 and D60). The animals were submitted to andrological examinations biweekly inside the periods, being evaluated the ponderal, testicular and seminal characteristics, and the enzymatic profiles. In the statistical analyses were used Anova and comparisons between averages according to de Kruskal-Wallis e Bonferroni Tests in the GraphPad Prism? vers?o 4.0 to Windows?. The obtained results indicate that (a) the antiparasitic treatments used in the preventive control in the natural infestations of ectoparasites do not influence negatively the ponderal and reproductive characteristics, and (b) the enzymes analyses AST and ALT, in the sanguine serum, evidenced do not be efficient methodology for evaluation of Nelore bull spermatogenesis implication. The prophylactic application of the antiparasitic drugs, in the pre-breeding season, in bulls created extensive is an efficient technique of ectoparasitism natural control to D. hominis and H. irritans, being the product choice be entailed to the application practicability and to the cost in each region. / Os ectoparasitas afetam os animais, acarretando grandes preju?zos a sa?de e consider?veis perdas econ?micas. A utiliza??o de antiparasit?rios de amplo espectro de a??o tem auxiliado na redu??o de perdas em decorr?ncia dessas infesta??es. Foram objetivos desse trabalho, avaliar os efeitos dos tratamentos antiparasit?rios, em doses terap?uticas, no controle preventivo da infesta??o natural por Dermatobia hominis e Haematobia irritans, sobre as caracter?sticas androl?gicas, perfil enzim?tico (AST e ALT) e correla??es nas caracter?sticas seminais de touros Nelore. Foram utilizados 20 touros de 24 a 30 meses de idade, criados a pasto (Brachiaria decumbens e B. brizantha). O experimento foi executado em delineamento inteiramente casualizado com quatro tratamentos (T1 = Controle, sem medica??o; T2 = Ivermectina injet?vel a 3,15%; T3 = Fipronil ?pour-on? e T4 = Doramectina a 1%), tr?s aplica??es dos tratamentos (0, 60 e 120 dias), cinco repeti??es (touros) e cinco coletas de s?men (D0, D15, D30, D45 e D60). Os animais foram submetidos a exames androl?gicos quinzenais dentro dos per?odos, sendo avaliadas as caracter?sticas ponderais, testiculares, seminais e perfil enzim?tico. Nas an?lises estat?sticas foram utilizados Anova e compara??es entre m?dias de acordo com os testes de Kruskal-Wallis e Bonferroni no programa GraphPad Prism? vers?o 4.0 para Windows?. As an?lises dos resultados obtidos indicam que (a) os tratamentos antiparasit?rios empregados no controle preventivos na infesta??o natural de ectoparasitos n?o influenciam negativamente as caracter?sticas ponderais e reprodutivas, e (b) as an?lises das enzimas AST e ALT, no soro sangu?neo, evidenciaram n?o ser metodologia eficiente para avalia??o de comprometimento da espermatog?nese de reprodutores bovinos da ra?a Nelore. A aplica??o antiparasit?ria profil?tica, na pr?-esta??o de monta, em touros criados extensivamente ? uma t?cnica eficiente para o controle de ectoparasitismo natural por D. hominis e H. irritans, devendo a escolha do produto estar vinculada ? praticidade de aplica??o e ao custo em cada regi?o.
3

S?ntese verde de nanopart?culas contendo prata e xilana do sabugo de milho: caracteriza??o f?sico-qu?mica e avalia??o das atividades antioxidante e antimicrobiana frente a protozo?rio e a fungos / Green synthesis of nanoparticles containing silver and xylan from corn cob: physicochemical characterization and evaluation of its antioxidant and antimicrobial activities against protozoa and fungi

Viana, Rony Lucas da Silva 30 October 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-12-04T21:15:20Z No. of bitstreams: 1 RonyLucasDaSilvaViana_DISSERT.pdf: 1958519 bytes, checksum: 226f3bd5e061571aedf5c25ed9beb5ac (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-12-08T23:09:18Z (GMT) No. of bitstreams: 1 RonyLucasDaSilvaViana_DISSERT.pdf: 1958519 bytes, checksum: 226f3bd5e061571aedf5c25ed9beb5ac (MD5) / Made available in DSpace on 2017-12-08T23:09:18Z (GMT). No. of bitstreams: 1 RonyLucasDaSilvaViana_DISSERT.pdf: 1958519 bytes, checksum: 226f3bd5e061571aedf5c25ed9beb5ac (MD5) Previous issue date: 2017-10-30 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O sabugo de milho ? um subproduto do cultivo do milho que ? pouco utilizado economicamente o que leva ao desperd?cio de milh?es de toneladas desse material anualmente. Do sabugo pode-se extrair mol?culas, inclusive um polissacar?deo bioativo, rico em xilose, denominado de xilana. Neste trabalho, foram produzidas, por um m?todo sustent?vel ao meio ambiente (s?ntese verde), nanopart?culas de prata contendo xilanas de sabugo de milho (nanoxilanas). Para tal, a xilana de sabugo de milho foi extra?da com o aux?lio de ondas de ultrassom. An?lises qu?micas mostraram que esta n?o estava contaminada por prote?nas nem por compostos fen?licos. A xilana foi hidrolisada e seus componentes monossacar?dicos foram determinados por cromatografia l?quida de alta efici?ncia (CLAE). Na an?lise monossacar?dica identificou-se os componentes sendo eles, xilose: glucose: galactose: manose: ?cido glucur?nico nas seguintes propor??es 50: 21: 14: 9: 2,5: 2,5, respectivamente. A forma??o das nanoxilanas foi acompanhada por espectroscopia UV-vis?vel com kmax = 469 nm. An?lises de espectroscopia de infravermelho confirmaram a presen?a da prata e xilana na nanopart?cula. J? as an?lises de dispers?o din?mica de luz e microscopia (DLS) e de for?a at?mica (MFA) mostraram que o tamanho das part?culas foi em m?dia de 102 nm e que essas tinham um formato arredondado. Os dados de DLS tamb?m mostraram que as nanoxilanas permaneceram est?veis por 12 meses quando armazenadas a 4 ?C e protegidas da luz. Dados de espectrometria de emiss?o ?ptica com plasma acoplado (ICP OES) mostraram que o percentual de prata na nanoxilana foi de 19%. A nanoxilana reduziu a viabilidade das formas promastigotas de Leishmania amazonensis (L. amazonensis) (IC50 25 ?g/mL), enquanto a xilana n?o foi efetiva nessa concentra??o. Al?m disso, a nanoxilana apresentou um valor de 7,5 ?g/mL correspondente a concentra??o m?nima inibit?ria para tr?s diferentes fungos Candida albicans, Candida parapsilosis, e Cryptococcus neorformans. Adicionalmente, a nanoxilana n?o alterou de forma negativa a redu??o de MTT a formazan por c?lulas normais (3T3). Os dados aqui apresentados mostram o potencial biotecnol?gico da nanoxilana e futuros ensaios, inclusive in vivo, devem ser feitos para confirmar o potencial antimicrobiano da nanoxilana. / Corn cob is an agricultural by-product that annually produces a huge amount of waste estimated at thousands of tons, and it is a source of xylan, a bioactive polysaccharide. In this article, silver nanoparticles containing xylan (nanoxylan) were synthesized using an environmentally friendly synthesis method. Therefore, for such, we extracted the xylan from corn cob using ultrasound. Proteins or phenolic compounds did not contaminate this xylan. In addition, HPLC analysis showed that it contains xylose: glucose: arabinose: galactose: mannose: glucuronic acid in a molar percentage ratio of 50: 21: 14: 9.0: 2.5: 2.5, respectively. The formation of nanoxylan was analyzed by UV?vis spectroscopy at kmax = 469 nm. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of silver and xylan in nanoxylan. Dynamic Light Dispersion (DLS) and Atomic Force Microscopy (AFM) showed size of ? 102.0 nm and spherical shaped nanoparticles, respectively. DLS also showed nanoxylans were stable for 12 months. Coupled plasma optical emission spectrometry (ICP OES) showed nanoxylan contain 19% of silver. Nanoxylan reduced viability of the promastigotes of Leishmania amazonensis (L. amazonensis) (IC50 25 ?g/mL), while xylan was not effective. In addition, nanoxylan showed antifungal activity on Candida albicans (MIC = 7.5 ?g/mL) Candida parapsilosis (MIC = 7.5 ?g/mL) and Cryptococcus neorformans (MIC = 7.5 ?g/mL). The data obtained here lead us to the conclusion that it is possible to synthesize silver nanoparticles with xylan and that these nanoxylans showed an antileishimanial and antifungal activities superior to the polysaccharide used for its synthesis, and that this can be used as a promising antiparasitic agent against these microorganisms.
4

Avalia??o estrutural e an?lise das atividades biol?gicas de pept?deos an?logos da stigmurina presente na pe?onha do escorpi?o Tityus stigmurus

Parente, Adriana Marina e Silva 28 November 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-04-02T15:02:41Z No. of bitstreams: 1 AdrianaMarinaESilvaParente_DISSERT.pdf: 1386035 bytes, checksum: 87910526a122893f94a9f3045c8c9c4f (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-04-05T13:08:04Z (GMT) No. of bitstreams: 1 AdrianaMarinaESilvaParente_DISSERT.pdf: 1386035 bytes, checksum: 87910526a122893f94a9f3045c8c9c4f (MD5) / Made available in DSpace on 2018-04-05T13:08:05Z (GMT). No. of bitstreams: 1 AdrianaMarinaESilvaParente_DISSERT.pdf: 1386035 bytes, checksum: 87910526a122893f94a9f3045c8c9c4f (MD5) Previous issue date: 2017-11-28 / Tityus stigmurus corresponde ? esp?cie de escorpi?o predominante na regi?o Nordeste do Brasil, sendo considerado um dos principais causadores de acidentes escorpi?nicos. Na pe?onha do T. stigmurus, que ? composta de uma mistura complexa de mol?culas de alta e baixa massa molecular, foi identificado e caracterizado um pept?deo antimicrobiano denominado Stigmurina (FFSLIPSLVGGLISAFK-NH2). Pept?deos antimicrobianos s?o pequenas mol?culas consideradas a primeira linha de defesa contra micro-organismos, apresentando amplo espectro de a??o antimicrobiana. A literatura reporta tamb?m a atividade desses pept?deos contra c?lulas cancer?genas. Sequ?ncias nativas de pept?deos bioativos como prot?tipo para a obten??o de novas mol?culas t?m sido utilizadas com o intuito de potencializar a sua atividade e reduzir a toxicidade. Nesse contexto, realizou-se a caracteriza??o estrutural in silico e por dicro?smo circular, bem como a avalia??o da atividade antimicrobiana, antiparasit?ria, antiproliferativa e hemol?tica de dois pept?deos an?logos obtidos ? partir da Stigmurina, denominados StigA3 e StigA4. A an?lise da conforma??o tridimensional in silico do StigA3 e StigA4 demonstrou uma estrutura helicoidal, sendo este resultado confirmado por dicro?smo circular. O aumento da carga superficial e do momento hidrof?bico de ambos os pept?deos an?logos quando comparado com a Stigmurina resultaram na potencializa??o da atividade antimicrobiana e antiparasit?ria. Os pept?deos StigA3 e StigA4 apresentaram a??o antiproliferativa semelhante ao pept?deo nativo, com exce??o para a c?lula normal, para qual os pept?deos an?logos se mostraram menos t?xicos. Portanto, estes resultados indicam uma potencial aplica??o terap?utica destes pept?deos an?logos, demonstrando a efici?ncia do desenho racional de f?rmacos para a obten??o de novos agentes antiproliferativos e anti-infecciosos. / Tityus stigmurus it?s the predominant scorpion specie in Northeast region from Brazil, it?s considered one of the main cause of scorpion accidents in this region. In T. stigmurus venom, which is a complex mixture of high and low molecular mass molecules, was identified an antimicrobial peptide denominated Stigmurin. Antimicrobial peptides are small molecules considered the first line of defense against microorganisms, they show broad spectrum action. Many authors have proved that these peptides can also be effective on cancerous cells. Mutation in these molecules sequence has been held aiming the increase in the activity maintaining its low toxicity. Therefore, it is proposed the characterization of the structure in silico and by circular dichroism, as well the antimicrobial, antiparasitic, anti-proliferative and hemolytic activities of two analog peptides from Stigmurin, denominated StigA3 and StigA4. We performed an in silico analysis for these peptides, where we were able to observe ?-helix structure, which was confirmed by circular dichroism. We were also able to find that the analog peptides net charge and hydrophobic moment were higher than Sitgmurin?s, which can explain the increase in antimicrobial and antiparasitic activity. The peptides StigA3 e StigA4 showed activity on cancerous cells similiar to the native peptide, except when tested on a normal cell we were able to find that they?re less toxic. Therefore, these results indicate a potential biotechnological application for the analogs peptides, even as prototype to new therapeutic agents.

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