The Study On Synthesis And Property Of Porphyrin-peptide Supramolecular System

Supramolecular system composed of porphyrin and peptides complexes plays significant role in nature due to their inherent biological function diversity.Fabrication of hierarchical supramolecular system from conjugates of porphyrins and peptides building blocks,and combination the unique photo and electronic properties of porphyrin with peptide scaffolds,has attracted much attention of scientists in the world.To construct functional materials from simple peptide decorated porphyrin derivatives through self-assembly,a series of porphyrin and peptides complexes was designed and synthesized.To take advantage of the scaffolding effect of peptide to modulate the photophysical properties of porphyrins,tetraphenylporphyrin conjugated at the N-terminus of L-di-phenylalanine was synthesized and self-assembled into nano-spheres,nano-particles and nano-sheets in hybrid solvent system.The porphyrin molecules in the assembly were arranged in the form of J-aggregates induced by the L-di-phenylalanine group.The absorption spectrum was broadened by the exciton coherence in the assembly.Diverse morphorlogies could be obtained by L-di-phenylalanine self-assembled in solvent system.To take advantage of the scaffold effect of L-di-phenylalanine in modulating the arrangement of porphyrins,conjugate of porphyrin and dipeptide was dissolved into different good solvent,and then self-assembled in aqueous solution with different p H values.Flowers-like micro-spheres,nano-capsules,nano-tubes,nano-fibers and nano-wires were obtained by modulating the ion state of the compound.The absorption spectra showed that the arrangement of porphyrins was mainly J-aggregation in the complexes,which demonstrated the succesful introduction of photophysical properties of porphyrins into peptide nanomaterials.Conjugates of porphyrins and L-di-phenylalanine with N-terminus and with blocked C-terminus were synthesized to investigate the relationship between the structure of the porphyrin building blocks and the self-assembling process in aqueous solution.Only nano-spheres and nano-fibers were formed by those compounds.It confirmed the significant effect of terminal L-di-phenylalanine group in selfassembly.To investigate the effect of chain length of peptide on self-assembly of porphyrin,small-molecule anti-tumor tetrapeptide MV modified tetraphenylporphyrin was designed and synthesized.The obtained porphyrin-peptide conjugate was selfassembled into micro-rod,micro-fibers and nanosperes in aqueous solution and physiological p H.The cytotoxicity of the porphyrin-peptide conjugates was investigated.We will further utilize the dual role of porphyrins and anti-tumor peptide to construct novel anti-tumor agents.