Study On Synthesis And Separation Performance Of Poly (Amino Acid) Benzyl Ester

This paper briefly introduced chirality, chiral drug, characteristic and preparation of optical resolution membrane.By obaining the L-glutamic acid-5-benzyl ester NCA and the L-aspartate-4-benzyl ester NCA with L-glutamic acid-5-benzyl ester and L-aspartate-4-benzyl ester as raw materials, two monomers were polymerized into poly(L-glutamic acid-5-benzyl ester) and poly(L-aspartate-4-benzyl ester) by ring opening polymerization in different solvents, respectively. The influence on yield, intrinsic viscosity and molecular weight for poly(L-glutamic acid-5-benzyl ester) and poly(L-aspartate-4-benzyl ester) were studied, and the reaction conditions were optimized. Those products were characterized with IR and 1HNMR.Since there are a large number of chiral recognition sites in poly(L-glutamic acid-5-benzyl ester) molecule, we dissolved the poly(L-glutamic acid-5-benzyl ester) in tetrahydrofuran, and coated it on 3-ammonia propyl triethoxy silica gel to prepare the chiral stationary phase. Four racemates and six position isomers were successfully separated on the chiral column with n-hexane and isopropyl alcohol as mobile phase.Poly(L-glutamic acid-5-benzyl ester) and poly(L-aspartate-4-benzyl ester) were used to prepare enantioselective membrane, and the D,L-hydroxy phenyl glycine was dissolved in solvent as feed solution. The effect on chiral separation was studied by different molecular weight of polymer, amount of DMF, concentration of feed solution, content of acetonitrile, dialysis time, etc. By the optimization of experimental conditions, the best separation(e.e.%) up to 45.48% and 40.14% were arrived for poly(L-glutamic acid-5-benzyl ester) and poly(L-aspartate-4-benzyl ester), respectively.