@PhdThesis{diss_mods_00012782, author = {Chandrasekaran, Vijayanand}, title = {Sweet switches: Azobenzene glycosides as photosensitive lectin inhibitors in solution and on surfaces}, year = {2013}, publisher = {Christian-Albrechts-Universit{\"a}t zu Kiel}, address = {Kiel}, keywords = {azobenzene glycosides; photoswitchable glycoconjugates; bacterial adhesion; photoisomerization}, abstract = {Non-covalent interactions between carbohydrate ligands and their lectin receptors are accompanied by conformational changes between the interacting partners. Such changes might reflect a principal conformational control of carbohydrate-protein interactions, which has received only little attention until to date. Hence, the central focus of this thesis is to synthesize photoswitchable glycomimetics and investigate the role of light-induced conformational changes in carbohydrate recognition. Thus azobenzene glycoconjugates are principal target molecules of our research. Photoirradiation of azobenzene glycosides at {\~} 365 nm induces E{\textrightarrow}Z isomerization leading to a certain E/Z ratio in the photostationary state (PSS). The special features of azobenzene glycoconjugates featuring an E{\textrightarrow}Z{\textrightarrow}E isomerization option in solution will eventually allow us to utilise this type of molecules with -D-mannose-specific lectins. In this context, a new class of azobenzene glycosides were synthesized and their photochromic properties were studied in solution by 1H NMR and UV-Vis spectroscopy and they were tested as inhibitors for type 1 fimbriae-mediated bacterial adhesion, such as the bacterial lectin FimH.. To mimic the cell surface glycocalyx, azobenzene glycosides were immobilised on gold surfaces to form photoswitchable glyco-SAMs. Photoisomerization was performed on the gold surface and monitored by IRRAS and UV-Vis spectroscopy. To get insight in the conformational control of carbohydrate recognition in a multivalence context, photosensitive glyconanopartices were also prepared and binding efficiency of different isomers was tested with the lectin ConA.}, url = {https://macau.uni-kiel.de/receive/diss_mods_00012782}, file = {:https://macau.uni-kiel.de/servlets/MCRFileNodeServlet/dissertation_derivate_00004974/Diss_Chandrasekaranpdf.pdf:PDF}, language = {en} }