Synthesis Of Potential Bioactive Of Cyclic Pentapeptide And Function Cyclic Octapeptide

Cyclic peptide and depsipeptide are a kind of important compound in marine natural products.As its special structure and properties,cyclic peptide has many important applications in chemistry,medicine,biology,materials,and so on.About synthetic cyclic peptide compounds,separation and structural reform has become a hot research field.Zygosporamide is isolated from the marine fungus cyclic pentapeptide esters containing a D-configuration amino acids.Its structure contains two L-phenylalanine,a D-leucine,an L-leucine,leucine,and a hydroxyl group.Zygosporamide has good physical activity,especially its anti-tumor activity.In the second chapter of this peper,According to homologous series and isostere principles of drug design,we designed a series of cyclic pentapeptide which the L-Phe in Zygosporamide was replaced by L-Tyr and which the L-Leu and L-Phe in Zygosporamide peptide were replaced by N-Me-Leu and 4-Br(orOMe)-L-Phe.Measuring the biological activity of the compound,and to explore the structure on the biological activity of cyclic peptides Zygosporamide modification.In the cyclic peptide structure,the cyclic peptide consists of a symmetrical structure of an even number of alternating D-and L-amino acid residues,due to its own plane of the ring showing the skeletal structure.Between the rings to form a network of intermolecular stacking by intermolecular hydrogen bonding,thus cyclic peptides self-assemble into nanotubes,It has potential applications in chemistry,biology,materials and medicine,therefore,the cyclic peptide nanotube research has become a hot today.The third chapter for the synthesis of cyclic peptides which containing a functional side arm.According to the design principle of the cyclic peptide nanotubes mainly L-alanine and D-type amino acid to form a ring-type light octapeptide,in order to enhance the rigidity of the ring with the N-methylated amino acid alanine instead of native L-alanine.Using L-N-methylated alanine instead of using L-alanine to increase the rigidity of the ring.Design,synthesis series cyclic octapeptide which containing a functional side arm,and study the synthesis method,through a side arm to a large ?-? of aromatic ring system interactions and hydrogen bonding cyclic peptide backbone interactions form a cyclic peptide self-assembly of nanotubes;Lay the foundation for the study of the factors which influence the nanotube self-assembly mechanism and function of the cyclic peptide nanotubes to explore the formation of aggregates formed.