Synthesis And Characterization Of Water-soluble Prophyrins With Peptide Dendrimers

The water-soluble porphyrins, with high fluoresence quantum yield, have attracted much attention due to their potential applications in chemistry, medicine, biology and biotechnology. In this paper, we designed and synthesised a series of water-soluble porphyrins with peptide dendrimers as a lyotropic group. We studied the influence of the molecular structure on the soluability and fluorescence properties.Key contents are as follows:1.L-asparagic acid was choosen as the momomeric building block, we successfully synthsised the first, second and third generation peptide dendrimer by use convergent approach in solution-phase. The EDCI was choosen as condensation agent and the reaction condition was very mild. All peptide dendrimers were synthesised with good yield from 61% to 96%.2.We improved the synthetic route of peptid dendrimer modified benzaldehyde. By optimizing the rate of reactants and reaction temperature, we effectively prevented the formation of Schiff base, and peptide dendrimer modified benzaldehydes were synthesised with good yield.3.We improved the Lindsey method and simultaneously investigate the effect of the structure and polarity of solvent on the reaction. Using tetrachloroethane as solvent, we synthesized the third generation peptide dendrimer modified porphyrins with good yield.4. We researched the relationship of the peptide dendrimer and the soluabilty of the porphyrins.The soluabity of the porphyrins in water was improved from 0.005 mg/mL to 1mg/mL.5.The fluorescence properties of the products was investigated and the fluorescence quantum yield in organic solvents were bettwen 16%-22% wich is higher than 11% of TPP in benzene. Especially, the fluorescence quantum yield is high in water, wich between 18%-24%.