关键词: 核磁共振, 生物材料, 合成聚肽, 聚羟乙谷氨酰胺-聚谷氨酸（PHEG-PBLG）

Abstract: Initiated by poly(hydroxylethyl glutamine), amphiphilic block copolymer of poly(hydroxylethyl glutamine (PHEG)) and poly(γ-benzyl-L-glutamate (PBLG)) was synthesized by polymerization of N-carboxyl anhydride (NCA). NCA monomer was synthesized by reacting γ-benzyl-L-glutamate with triphosgene. The constitution, molecular weight and α-helical structures of the resulting block copolymers were studied by NMR and enzymolysis of the black polymers in vitro was discussed. The results showed that the copolymers with different block-ratio of PHEG/PBLG had different molecular weights, being 1.27×10⁴, 1.75×10⁴, 1.9×10⁴ and 3.60×10⁴ when the A/I ratios were 75∶1, 100∶1, 150∶1 and 200∶1, respectively. The copolymers contained α-helix structures in CHCl₃, which could be converted into random coils with addition of TFA.

Key words: biomaterials, synthetic polypeptide, NMR, poly (hydroxylethyl glutamine) and poly-(γ-benzyl-L-glutamate)