Darstellung photolabiler Mannose-Derivate zur Markierung des Typ-1-fimbrialen Lectins aus E.coli
Escherichia coli bacteria possess so called type 1 fimbriae to adhere to alpha-mannosyl residues present in the glycocalyx of potential host cells. It has been the goal of this thesis to synthesize mannose derivatives, which are equipped with a photolabile diazirine group to facillitate research, which is aimed at the elucidation of the details of the molecular interaction between the lectin domain FimH and carbohydrates. Eventually, these derivatives could be incubated with FimH and irradiated to allow a peptide digestion and spectrometric investigation of the covalently linked protein-carbohydrate adduct. The diazirine group has been incorporated into the aglycone part of O-glycosides and thiourea-linked derivatives, respectively. To introduce a broad variety of structures a modular concept has been developed using convergent synthesis and the knowledge of graded reactivities of two different isothiocyanato groups in a difunctionalized mannose derivative. In combination with glycosylation reactions this concept was introduced to the synthesis of photolabelled di- and trivalent mannosyl clusters.