Synthesis of amphiphilic hairy rod diblock poly(glutamic acid)-b-poly(benzyl glutamate-r-octadecyl glutamate)

Tóm tắt

Diblock copolypeptide poly(glutamic acid) -b-poly (benzyl glutamate-r-octadecyl glutamate) has a great potential for biological stabilization and optical orientation. This study reports on the synthesis and characterization of an amphiphilic diblock copolypeptide of poly(glutamic acid) and poly(benzyl glutamate-r-octadecyl glutamate) possessing the a-helical secondary structure. To obtain this copolypeptide, a precursor copolymer with an acid-labile protecting group for the carboxylic acid was prepared through glutamate-N-carboxy anhydride polymerization, followed by removal of the protecting group using a straightforward and highly efficient process. The precursor and the synthesized diblock copolymer were characterized by using nuclear magnetic resonance spectroscopy (NMR) and attenuated total reflection-Fourier transform infrared (ATR FT-IR). The α-helix conformation of poly (glutamic acid) -b-poly (benzyl glutamate-r-octadecyl glutamate) was identified by the characteristic α-helix amide I and amide II bands at 1651 cm^-1 and 1547 cm^-1 respectively, the thermal properties of this diblock copolypeptide shown on a result of TGA for observing thermally stable up to 215 ^oC.