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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

Aplicação da reação de Pictet-Spengler na síntese de alcaloides fenil tetrahidroisoquinolínicos inéditos

Cordeiro, Manuela Barbosa 29 August 2012 (has links)
Made available in DSpace on 2015-05-14T12:59:52Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3215575 bytes, checksum: 8de9cf3f200ed4dc0ee4d1b0b672ce4f (MD5) Previous issue date: 2012-08-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The number of alkaloids containing the 1-substituted tetrahydroisoquinoline skeleton is extensive and impressive versatility of this pharmacological class arouses interest in experimental pharmacologists. Applying the consecrated Pictet-Spengler reaction of four phenyltetrahydroisoquinoline alkaloids was obtained, three of which are unpublished. Two of them obtained with excellent yield (93.45%) in one step. Starting from allylbenzene that initially passed through an isomerization followed by oxidation by applying the Limieux-Johnson reaction were obtained from two other alkaloids with an overall yield of 50%. In experimental models of acute inflammation, the 1-(3-methoxy-4-hydroxyphenyl)-7-methoxy-1,2,3,4,tetrahydroisoquinoline (MTHP) significantly reduced (p <0.05) cell migration into the abdominal cavity of mice and the release of pro-inflammatory mediators (TNF-α, IL-1 and IL-6) in a dose one hundred thirty-eight times lower dosage than the dose of aspirin administered (200 mg/Kg).The MTHP causes hypotension in non-anesthetized normotensive rats, which can be attributed to the participation of endothelium-derived factors, including NO and metabolites COX. These data suggest that MTHP has anti-inflammatory and hypotensive effect related to different mechanisms, and further studies are needed to explore its potential. / O número de alcaloides que contém o esqueleto tetrahidroisoquinolínico 1-substituído é extenso e a impressionante versatilidade farmacológica desta classe desperta o interesse nos farmacologistas experimentais. Aplicando a consagrada reação de Pictet-Spengler obtivemos quatro alcaloides fenil tetrahidroisoquinolínicos dos quais três são inéditos. Dois deles obtidos com excelente rendimento (93,45%) em uma única etapa. Partindo-se de alilbenzenos que inicialmente passaram por uma isomerização seguida de oxidação via reação de Limieux-Johnson, foram obtidos os outros dois alcaloides com rendimento global de 50%. Em modelo experimental de inflamação aguda, a 1-(3-metoxi-4-hidroxifenil)-7-metoxi-1,2,3,4,-tetrahidroisoquinolina (MTHP) reduziu significativamente (p<0,05) a migração celular para a cavidade abdominal de camundongos bem como a liberação dos mediadores pró-inflamatórios (TNF-, IL-1 e IL-6) em uma dose cento e trinta e oito vezes menor que a dose de AAS administrada (200mg/Kg i.p.). MTHP provoca hipotensão em ratos normotensos não anestesiados, que pode ser atribuída à participação de derivados do endotélio, incluindo fatores de NO e metabolitos COX. Estes dados sugerem que MTHP tem efeitos anti-inflamatórios e hipotensores relacionados a diferentes mecanismos, e novos estudos são necessários para explorar seu potencial.

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