Method for synthesizing polypeptide in presence of ammonia-base rare earth catalyst

Abstract

The invention discloses a method for synthesizing polypeptide in the presence of ammonia-base rare earth catalyst, which is characterized in that: tri(bis(trimethylsilyl)) rare earth metal compound is used as a catalyst to catalyze the ring-opening polymerization of a benzyl-gama-glutamate-N-carboxylic anhydride monomer to synthesize the polypeptide of which the molecular weight is 18,000 to 80,000, wherein the molar ratio of the catalyst to the monomer is 1:80 to 1:1,200; the reaction temperature is 0 to 60 DEG C; the reaction time is 1 to 3 days; a solvent is N,N-dimethylformamide; and the concentration of the monomer is 0.5mol / L. Compared with the prior art, the method has the advantages that: the used catalyst is cheap and easy to prepare and has high catalytic activity; and the molecular weight of the prepared polypeptide is controllable and the molecular distribution of the prepared polypeptide is narrow.

Description

technical field [0001] The invention relates to a method for synthesizing a polypeptide, in particular to a method for catalyzing the synthesis of a polypeptide with an amino rare earth catalyst. technical background [0002] Polypeptide is a kind of low toxicity, good biocompatibility, biodegradable polymer material, which is widely used in the research of biomedical field. Polypeptides can be made from natural amino acids, with rich sources of raw materials, and can be absorbed by the body after degradation in the body without causing inflammation. It is an ideal biological material. Compared with conventional polymer materials, polypeptides can form stable secondary structures such as α-helices and β-sheets. This self-assembly ability makes them have great prospects for biomedical and pharmaceutical applications, especially in medical fields such as drugs Controlled release, tissue engineering, biosensing and other aspects have its unique role. [0003] There are three ...

AI Technical Summary

Problems solved by technology

The defect of this system is that the final product contains nickel metal, which affects its biological application (Nature, 1997, 390, 386-387); 2) In 2003, Schlaad et al reported a controllable NCA ring-opening polymerization method , using primary amine hydrochloride as a macroinitiator to catalyze the synthesis of polypeptides, the molecular weight distribution of the resulting product is very narrow, only 1.03, but the system’s reactivity is not high, and the monomers cannot react completely (Chem.Commun, 2003, 2944 -2945); 3) In 2004, people such as N.Hadjichristidis of Greece realized the living polymerization of NCA with traditional primary amines as initiators under high vacuum conditions, but this system requires very high purity of NCA monomers. Moreover, high vacuum conditions are not easy to realize, and the operation is also very complicated (Biomacromolecules, 2004, 5, 1653-1656); 4) In 2007, J.Cheng et al. developed a bistrimethylsilazane (HMDS) catalytic system, and the product molecular weight Controllable, narrow molecular weight distribution (1.19<PDI<1.26), high yield, almost 100%, see J.Am.Chem.Soc.2007, 129, 14114-14115; 5) 2008, C.Lin et al. Using [bis(diphenylethane)][N-(2-amino-1,2-diphenylethyl)-4-methylbenzenesulfonamide]platinum complex ((deep)Pt(MBS- NH)) as a catalyst can effectively initiate the ring-opening polymerization of lysine NCA, and the molecular weight of the obtained polypeptide is controllable and the molecular weight distribution is narrow. Body (Macromolecules, 2008, 41, 3455-3459)

So far, there is no report on the ring-opening polymerization of amino acid NCA monomer catalyzed by amino rare earth compounds

Images