Synthesis, structure and conformation of oligo- and polysaccharides

Carbohydrates are a complex group of biomolecules with a high structural diversity. Their almost omnipresent occurrence has generated a broad field of research in both biology and chemistry. This thesis focuses on three different aspects of carbohydrate chemistry, synthesis, structure elucidation and the conformational analysis of carbohydrates. The first paper describes the synthesis of a penta- and a tetrasaccharide related to the highly branched capsular polysaccharide from Streptococcus pneumoniae type 37. In the second paper, the structure of the O-antigenic repeating unit from the lipopolysaccharide of E. coli 396/C1 was determined along with indications of the structure of the biological repeating unit. In addition, its structural and immunological relationship with E. coli O126 is discussed. In the third paper, partially protected galactopyranosides were examined to clarify the origin of an intriguing 4JHO,H coupling, where a W-mediated coupling pathway was found to operate. In the fourth paper, the conformation of methyl a-cellobioside is studied with a combination of molecular dynamics simulations and NMR spectroscopy. In addition to the expected syn-conformation, detection and quantification of anti-ø and anti-ψ conformers was also possible.

Extractivism and the de jure and de facto ethno-territorial rights in Latin America: How important are the constitutions? : Extractivismo y derechos étnico-territoriales de jure y de facto en Latinoamérica: ¿Cuán importantes son las constituciones?

A growing number of Latin American rural groups have attained extended ethno-territorial rights, and sizeable territories were safeguarded by progressive constitutions. This trend was the product of extended cycles of protest at local, national and transnational levels; social movements struggle, with broader collective South-South collaboration. Nonetheless, the continent simultaneously experienced a resource extraction boom. Commonly, the extractivism takes place in protected areas and/or indigenous territories. Accordingly, economic interests clash with the safeguarding and recognition of constitutional rights. Through the analysis of selected illustrative cases across Latin America, this study analyses the (de jure) rights on paper versus the (de facto) rights in practice.