The Studies On The Synthesis And Self-assembly Of ?-cyclic Peptide Nanotubes

Self-assembled cyclic peptide nanotubes can be used for antibacterial,biosensor,optoelectronic materials,drug delivery and ion channels because of their specific structure,biocompatibility and property controllability.At present,studies on the self-assembled nanotubes of ?-cyclic peptides,?-cyclic peptides,?-cyclic peptides,?,?-alternating cyclic peptides and ?,?-alternating cyclic peptides have been reported,however,few studies have been reported on the assembly of ?-cyclic peptide molecules into nanotubes.So the properties research of gamma amino acid polypeptide,cyclic peptide and cyclic peptide nanotubes has a potential application prospect in chemistry,biology and medicine and other fields.Therefore,the synthesis,assembly,characterization and channel properties of ?-cyclic peptides were studied in this paper,which provided theoretical and experimental basis for the further study of ?-cyclic peptides.And the results are as follows:1.We got optically pure 3-aminocyclohexyl formic acid(?-Ach)through iodolactonization,deiodinase and palladium catalyzed azide ring opening,selective reduction of azides,amino protection,chiral separation and hydrogenation reduction,using the 3-cyclohexenecarboxylic acid as raw material.And then a series of rigid structure of ?-cyclic tetrapeptides and ?-cyclic hexapeptides with biocompatible TEG side chain were synthesized by ?-Ach and the1 H NMR,13 C NMR,HRMS,MALDI-TOF-MS and FT-IR were used to confirm the structure.2.The target molecule ?-cyclic tetrapeptide 21 and ?-cyclic hexapeptide 24 were tested by variable temperature and concentration of NMR,variable concentration of UV and IR.It was found that hydrogen bonds and ?-? acted to support cyclic peptide self-assembly and were assembled in beta-folded form.3.The morphology of the assembly structure of the assembly of ?-cyclic tetrapeptide 21 and ?-cyclic hexapeptide 24 were observed by atomic force microscopy(AFM)and transmission electron microscopy(TEM),it was found that the ?-cyclichexapeptide 24 was easy forming a single fibrous structure.And in the acetonitrile /water system,the morphology of the ?-cyclic tetrapeptide 21 and ?-cyclic hexapeptide24 assembly from the solid to the coarse fibers to the membrane structure,as the water content increases,it was confirmed that the addition of polar solvent could affect the morphology of the cyclic peptide assembly and play a role in the regulation.4.The data of ?-cyclic tetrapeptide 21 and ?-cyclic hexapeptide 24 in water channel experiments and ion(Cl-,H+,OH-)channel fluorescence experiments found that the ?-cyclic tetrapeptide 21 was only capable of carrying out OH-transmembrane transport,and ?-cyclic hexapeptide 24 can be carried out H2 O and OH-transmembrane transport,neither of them can carry out the transport of Cl-,H+ with cationic ACh +,Na+and K+.