Solid phase and combinatorial synthesis of receptors for small peptides
In the first chapter of this thesis recent developments in host-guest chemistry are reviewed, in particular receptors for carboxylic acids and small peptides. The applications of solid phase and combinatorial chemistry in the synthesis of receptors are also described. Chapter 2 describes the synthesis of a CBS (carboxylic acid binding site) functionalised to allow attachment to the solid support, and synthesis of a library of tweezer receptors. The library was screened with different labelled peptide guests and receptor structures were identified. One example of such receptors was resynthesised and binding studies in free solution were attempted. Chapter 3 describes the attempt to synthesise an “unsymmetrical” tweezer receptor library with different sequences of amino acids in the two peptidic arms. Chapter 4 describes the synthesis of b-sulfonamido derivatives used in the synthesis of a further example of a tweezer receptor, and binding studies on this class of receptors showed selectivity for the peptide L-Ala-L-Ala. Chapter 5 describes the synthesis of a further receptor library incorporating a bicyclic guanidinium as CBS and screening experiments with dye labeled D-Ala-D-Ala. Chapter 6 describes the synthesis of the various peptides used as guests in the various screening experiment.