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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

Síntese e estudo das interações de 3-(fosfato)- e 3-(fosfonamida)-4,4,4-trifluor-but-1-il-carbamatos de etila com a enzima acetilcolinesterase e síntese de 3-carboxietil- e 3-pirimidin-2-il-2-oxo-6-trifluormetil-[1,2,3]oxatiazinanas / Synthesis and interactions studies of 3-phosphate- and 3-phosphonamide-4,4,4-trifluoro-but-1-yl-carbamic acid ethyl esters with acetylcholinesterase enzyme and synthesis of 3-carboxyethyl- and 3-pyrimidin-2-yl-2-oxo-6-trifluoromethyl-[1,2,3]oxathiazinanes

Borchhardt, Deise Moreira 01 March 2007 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / A series of [3-(phosphate)-4,4,4-trifluoro-but-1-yl]-carbamic acid ethyl ester and [3-(phosphonamide)-4,4,4-trifluoro-but-1-yl]-carbamic acid ethyl ester obtained from the reaction of g-amino alcohols (4,4,4-trifluoro-3-hydroxy-butan-1-yl)-carbamic acid ethyl ester with phosphorus oxychloride in the presence of base and subsequent reaction with alcohols or amines. In addition, this work describes the synthesis and characterization of 3-carboxyethyl-2-oxo-6-trifluoromethyl-[1,2,3]oxathiazinanes and 3-[pyrimidin-2-yl]-2-oxo-6-trifluoromethyl-[1,2,3]oxathiazinanes obtained from the cyclization reaction of the g-amino alcohols (4,4,4-trifluoro-3-hydroxy-butan-1-yl)-carbamic acid ethyl ester and 4-(pyrimidin-2-ylamino)-1,1,1-trifluoro-butan-2-ols with thionyl chloride in the presence of a base. The g-amino alcohols used in this work were obtained from synthetic routes using as precursor b-alkoxyvinyl trifluoromethyl ketones with general formula F3CC(O)CH=C(R)OR1, where R = H, Me, Pr, Bu, Ph, 4-Me-Ph; R1 = Me, Et. The b-alkoxyvinyl trifluoromethyl ketones were obtained from the acylation of acetals or enolethers with trifluoroacetic anhydride. The effect of the carbamates containing phosphate group in the inhibition of acetylcholinesterase enzyme was tested. Several compounds exhibited significant inhibition of this enzyme. Molecular modeling studies were developed to elucidate the interaction mode of these new inhibitors. The oxathiazinanes were assessed against a panel of microorganisms including yeast like fungi, bacteria and algae, but no activity was found. / Uma série de [3-(fosfato)-4,4,4-trifluor-but-1-il]-carbamatos de etila e [3-(fosfonamida)-4,4,4-trifluor-but-1-il]-carbamatos de etila foram obtidos a partir da reação de g-amino álcoois (4,4,4-trifluor-3-hidróxi-butan-1-il)-carbamatos de etila com oxicloreto de fósforo na presença de base e subseqüente reação com álcoois ou aminas. Este trabalho apresenta também a síntese e caracterização de 3-carboxietil-2-oxo-6-trifluormetil-[1,2,3]oxatiazinanas e 3-[pirimidin-2-il]-2-oxo-6-trifluormetil-[1,2,3]oxatiazinanas obtidas por reação de ciclização dos g-amino álcoois (4,4,4-trifluor-3-hidróxi-butan-1-il)-carbamatos de etila e 4-(pirimidin-2-ilamino)-1,1,1-trifluor-butan-2-ols com cloreto de tionila na presença de base. Os g-amino álcoois utilizados neste trabalho foram obtidos por rotas sintéticas que tem como precursor as b-alcoxivinil trifluormetil cetonas de fórmula geral F3CC(O)CH=C(R)OR1, onde R = H, Me, Pr, Bu, Ph, 4-Me-Ph; R1 = Me, Et. As b-alcoxivinil trifluormetil cetonas utilizadas foram obtidas através de acilação de acetais ou enol éteres com anidrido trifluoracético. O efeito dos carbamatos contendo grupo fosfato na inibição da enzima acetilcolinesterase foi avaliado. Vários compostos apresentaram inibição significante dessa enzima e estudos de modelagem molecular foram desenvolvidos para elucidar o modo de interação destes novos inibidores. As oxatiazinanas foram testadas na inibição do crescimento de microorganismos incluindo leveduras como fungos, bactérias e alga, porém, não apresentaram atividade inibitória
2

Estudo quÃmico de rizomas de Alpinia zerumbet: inibidores da enzima de conversÃo da angiotensina, com potencial antioxidante e de inibiÃÃo da acetilcolinesterase / Chemical study of Alpinia zerumbet rhizomes: angiotensin converting enzyme inhibitors, antioxidant potential and acetylcholinesterase inhibition

Ricardo Farias de Almeida 31 October 2012 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A hipertensÃo, uma das doenÃas mais comuns em todo o mundo, Ã uma doenÃa crÃnica onde a pressÃo sanguÃnea elevada pode afetar a saÃde. A enzima conversora de angiotensina I (ECA) pode aumentar a pressÃo arterial atravÃs da conversÃo da angiotensina I no potente vasoconstritor angiotensina II. Sendo assim, a inibiÃÃo da atividade da ECA Ã considerada uma abordagem terapÃutica Ãtil para combater a hipertensÃo. Alpinia zerumbet, uma planta aromÃtica abundante no nordeste do Brasil, Ã comumente utilizada na medicina popular devido suas propiedades diurÃticas e hipotensivas. AlÃm disso, vÃrios estudos relatam atividade antihipertensiva para esta espÃcie. Dessa forma, Alpinia zerumbet pode ser uma importante fonte de inibidores de ECA. Sabendo disso, resolveu-se investigar os extratos dos rizomas desta espÃcie na busca de compostos inibidores de ECA. A prospecÃÃo quÃmica do extrato hexÃnico do rizoma permitiu o isolamento de cinco substÃncias: Um estilbeno denominado (E)-3,5-dimetoxiestilbeno, inÃdito na espÃcie em estudo; um diterpeno de esqueleto labdano denominado (E)-15,16-bis-norlabda-8,11-dieno-13-ona; uma chalcona denominada 2â,4â-dihidroxi-6â-metoxi-3â-(3ââ-metil-6ââ-metil-etil-2ââ-ciclohexenil)chalcona; um esterÃide denominado β-sitosterol, comumente encontrado em plantas; e um hidrocarboneto aromÃtico da classe kavapirona denominado 5,6-dehidrokawain. Na determinaÃÃo estrutural dos compostos isolados, foram empregadas tÃcnicas espectromÃtricas de anÃlise unidimensionais [ressonÃncia magnÃtica nuclear (RMN) de 1H e 13C, e tÃcnicas bidimensionais (1H-1H-COSY, HSQC, HMBC, NOESY). TambÃm foram realizados os testes de inibiÃÃo da enzima conversora de angiotensina, antioxidante, de inibiÃÃo da enzima acetilcolinestarase e larvicida dos extratos hexÃnicos e etanÃlicos dos rizomas de Alpinia zerumbet. Os dois extratos apresentaram potencial de inibiÃÃo da enzima conversora de angiotensina e antioxidante. Somente o extrato hexÃnico apresentou atividade larvicida, com CL50 823,1 ppm. Nenhum dos extratos em estudo apresentou potencial de inibiÃÃo da enzima acetilcolinesterase. / Hypertension is one of the most common diseases in the world, is a chronic disease in which high blood pressure can affect health. The angiotensin I converting enzyme (ACE) can increase blood pressure through the conversion of angiotensin I to the potent vasoconstrictor, angiotensin II. Thus, inhibition of ACE activity is considered a useful therapeutic approach to combat hypertension. Alpinia zerumbet, a herb abundant in northeastern Brazil, is commonly used in folk medicine due to its diuretic and hypotensive properties. Moreover, several studies reported for this species antihypertensive activity. Thus, Alpinia zerumbet can be an important source of ACE inhibitors. Knowing this, we decided to investigate the extracts of the rhizomes of this species in the search for compounds ACE inhibitors. Prospecting chemical hexane extract of the rhizome allowed the isolation of five substances: A stilbene, named (E) -3,5-dimethoxystilbene, unprecedented in the species in this study, a labdane diterpene skeleton called (E) -15.16-bisnorlabda- 8,11-diene-13-one; one chalcone called 2â,4â-dihydroxy-6â-methoxy-3â-(3ââ-methyl-6ââ- methyl - ethyl -2ââ-cyclohexenyl) chalcone; a steroid called β-sitosterol, commonly found in plants, and an aromatic hydrocarbon class kavapirone, called 5,6- dehidrokawain. In the structural determination of individual compounds, spectrometric techniques were employed dimensional analysis [nuclear magnetic resonance (NMR) 1H and 13C and two dimensional techniques (1H-1H COSY, HSQC, HMBC, NOESY). Inhibition angiotensin converting enzyme, antioxidant potential, inhibition of acetilcolinestarase and larvicidal tests of ethanol and hexane extracts of the rhizomes of Alpinia zerumbet were tested. The two extracts showed potential for inhibition of angiotensin converting enzyme and antioxidant potential. Only the hexane extract showed larvicidal activity with LC50 823.1 ppm. None of the extracts studied showed potential inhibition of the enzyme acetylcholinesterase.

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