Development of an organocatalytic method for the enantioselective synthesis of rivastigmine

The focus of this thesis was the study of a recently developed class of picolinamide cinchona alkaloid derivatives for the synthesis of Rivastigmine, a biologically active compound used for the treatment of Alzheimer’s disease. Six 9-picolinamide-cinchona alkaloid derivatives were successfully synthesized through simple and effective methods. These catalysts were then applied in the enantioselective reduction of O-protected ketimines (intermediates of Rivastigmine). The hydrosilylation of the N-phenyl ketimines afforded good results with excellent yields and high enantioselectivities, while much lower values, in terms of both enantioselectivity and yield, were obtained in the reduction of N-benzyl ketimines. Preliminary studies on the immobilization of these organocatalysts to different solid supports were conducted, with the purpose of applying them in continuous flow systems, which to date has never been reported; RESUMO: No âmbito deste trabalho, foi estudada a síntese de um composto biologicamente ativo usado para o tratamento da doença de Alzheimer, Rivastigmina, usando uma classe de picolinamidas derivadas de alcaloides de cinchona recentemente desenvolvida. Seis 9-picolinamida derivados de alcaloides de cinchona foram preparados com êxito através de metodologias simples e eficazes. Os organocatalisadores foram posteriormente aplicados na redução enantiosseletiva de cetiminas O-protegidas (intermediários de Rivastigmina). Foram obtidos bons resultados na hidrossililação de N-fenilo cetiminas, com rendimentos excelentes e elevadas enantiosseletividades, enquanto a redução de N-benzilo cetiminas proporcionou valores muito mais baixos, tanto em termos de rendimento como de enantiosseletividade. Com o objetivo de serem aplicados em sistemas de fluxo contínuo, realizaram-se estudos preliminares sobre a imobilização destes organocatalisadores em diferentes suportes sólidos, a qual, ate à data, ainda não foi descrita na literatura.

A real time Taqman RT-PCR for the detection of rabbit hemorrhagic disease virus 2 (RHDV2)

As key prey, the wild rabbit downsize constitutes a major drawback on the endangered Iberian lynx (Lynx pardinus) re-introduction in the Iberia. Several captive breeding units mostly located in Alentejo, endeavour the wild rabbit repopulation of depleted areas assigned for the lynx re-introduction. Here we report an RHDV2 outbreak that occurred in early 2016 in a wild rabbit captive breeding unit located in Barrancos municipality. The estimated mortality rate between March and April 2016 was approximately 8.67%. Anatomopathologic examination was carried out for 13 victimized rabbits. Molecular characterization was based on the complete vp60 capsid gene. The 13 rabbit carcasses investigated showed typical macroscopic RHD lesions testing positive to RHDV2- RNA. Comparison of the vp60 nucleotide sequences obtained from two specimens with others publically available disclosed similarities below 98.22% with RHDV2 strains originated in the Iberia and Azores and revealed that the two identical strains from Barrancos-2016 contain six unique single synonymous nucleotide polymorphisms. In the phylogenetic analysis performed, the Barrancos-2016 strains clustered apart from other known strains, meaning they may represent new evolutionary RHDV2 lineages. No clear epidemiological link could be traced for this outbreak where the mortalities were lower compared with previous years. Yet, network analysis suggested a possible connection between the missing intermediates from which the strains from Barrancos 2013, 2014 and 2016 have derived. It is therefore possible that RHDV2 has circulated endemically in the region since 2012, with periodic epizootic occurrences. Still, six years after its emergence in wild rabbits, RHDV2 continues to pose difficulties to the establishment of natural wild rabbit populations that are crucial for the self-sustainability of the local ecosystems.

Tracking the Origin of a Rabbit Haemorrhagic Virus 2 Outbreak in a Wild Rabbit Breeding Centre in Portugal; Epidemiological and Genetic Investigation

As key prey, the wild rabbit downsize constitutes a major drawback on the endangered Iberian lynx (Lynx pardinus) re-introduction in the Iberia. Several captive breeding units mostly located in Alentejo, endeavour the wild rabbit repopulation of depleted areas assigned for the lynx re-introduction. Here we report an RHDV2 outbreak that occurred in early 2016 in a wild rabbit captive breeding unit located in Barrancos municipality. The estimated mortality rate between March and April 2016 was approximately 8.67%. Anatomopathologic examination was carried out for 13 victimized rabbits. Molecular characterization was based on the complete vp60 capsid gene. The 13 rabbit carcasses investigated showed typical macroscopic RHD lesions testing positive to RHDV2-RNA. Comparison of the vp60 nucleotide sequences obtained from two specimens with others publically available disclosed similarities below 98.22% with RHDV2 strains originated in the Iberia and Azores and revealed that the two identical strains from Barrancos-2016 contain six unique single synonymous nucleotide polymorphisms. In the phylogenetic analysis performed, the Barrancos-2016 strains clustered apart from other known strains,meaning they may represent new evolutionary RHDV2 lineages. No clear epidemiological link could be traced for this outbreak where the mortalities were lower compared with previous years. Yet, network analysis suggested a possible connection between the missing intermediates from which the strains from Barrancos 2013, 2014 and 2016 have derived. It is therefore possible that RHDV2 has circulated endemically in the region since 2012, with periodic epizootic occurrences. Still, six years after its emergence in wild rabbits, RHDV2 continues to pose difficulties to the establishment of natural wild rabbit populations that are crucial for the self-sustainability of the local ecosystems.

Tracking the Origin of a Rabbit Haemorrhagic Virus 2 Outbreak in a Wild Rabbit Breeding Centre in Portugal; Epidemiological and Genetic Investigation

As key prey, the wild rabbit downsize constitutes a major drawback on the endangered Iberian lynx (Lynx pardinus) re-introduction in the Iberia. Several captive breeding units mostly located in Alentejo, endeavour the wild rabbit repopulation of depleted areas assigned for the lynx re-introduction. Here we report an RHDV2 outbreak that occurred in early 2016 in a wild rabbit captive breeding unit located in Barrancos municipality. The estimated mortality rate between March and April 2016 was approximately 8.67%. Anatomopathologic examination was carried out for 13 victimized rabbits. Molecular characterization was based on the complete vp60 capsid gene. The 13 rabbit carcasses investigated showed typical macroscopic RHD lesions testing positive to RHDV2- RNA. Comparison of the vp60 nucleotide sequences obtained from two specimens with others publically available disclosed similarities below 98.22% with RHDV2 strains originated in the Iberia and Azores and revealed that the two identical strains from Barrancos-2016 contain six unique single synonymous nucleotide polymorphisms. In the phylogenetic analysis performed, the Barrancos-2016 strains clustered apart from other known strains, meaning they may represent new evolutionary RHDV2 lineages. No clear epidemiological link could be traced for this outbreak where the mortalities were lower compared with previous years. Yet, network analysis suggested a possible connection between the missing intermediates from which the strains from Barrancos 2013, 2014 and 2016 have derived. It is therefore possible that RHDV2 has circulated endemically in the region since 2012, with periodic epizootic occurrences. Still, six years after its emergence in wild rabbits, RHDV2 continues to pose difficulties to the establishment of natural wild rabbit populations that are crucial for the self-sustainability of the local ecosystems.