טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentRuth Goldschmidt
SubjectNew Corroles with Desirable Features for Light-Driven
Applications
DepartmentDepartment of Chemistry
Supervisor Full Professor Gross Zeev


Abstract

One approach for creating new biomaterials, for applications such as PDT (photodynamic therapy) and PDD (photodynamic detection) or for asymmetric catalysis, is to replace the native prosthetic group of enzymes or proteins by an artificial macromolecule. This is a main driving force of research devoted to explore interactions between synthetic chromophores and hemo-proteins. The principal requirements from the chromophores are absorption of low-energy wavelengths, amphiphilicity and steric sizes that are compatible with the binding site of the protein. Corroles, tetra-pyrrolic synthetic macrocycles with a direct link between two of their four pyrrolic rings, are well-suited potential candidates for this task. Their C2v symmetry permits selective substitution reactions on the skeleton as a route to amphiphilic chromophores. However, all known corroles contain large substituents on the meso-positions, which could sterically hinder the entrance into the limited-size pocket of myoglobin and similar proteins. The goal of this study was to synthesize new kinds of corroles that don’t suffer from such limitations and to check their interactions with myoglobin. Many synthetic pathways were investigated for this purpose, with the most fruitful one being the reaction between CF3-substituted dipyrromethane and a reactive aldehyde. This approach provided the "thin" 5,15-bis(trifluoromethyl)-10-(pentafluorophenyl)corrole. Insertion of cobalt to the corresponding metal complex, and both the free-base and the cobalt corrole were fully characterized by NMR, UV-vis, MS and X-ray crystallography methods. Amphiphilic derivatives were obtained by sulfonation and used for obtaining preliminary indications for strong interactions with myoglobin, based on circular dichroism and UV-vis spectroscopic methods. The protein-corrole conjugates absorb light at long wavelengths, an important feature for future utilization.