Preparation Of Protein-Functionalized Magnetic Nanoparticles And Their Chiral Resolution Performance

Although chiral drugs have the same chemical structure, most isomers of chiraldrugs exhibit marked differences in biological activities such as pharmacology,metabolism and metabolism product, toxicology etc. For example, one of theenantiomers has active effect while the other has lower effect or no effect or eventoxic effect. So it has become a research focus for institutes and industries to develophighly-efficient technologies to obtain optical pure enantiomers. The use of protein aschiral selectors has been widely used in the area of chiral separation. In this work,magnetic nanoparticles were used as vectors for the immobilization of thebiomacromolecules with chiral recognition property, and were further used as chiralselectors for the chiral separation of ibuprofen.The magnetic nanoparticles were synthesized by co-precipitation method with asize of15nm characterized by TEM, and the saturation magnetization is70.02emu/gwith a spinel structure. The surface of the particle is modified by poly dimethyl diallylammonium chloride (PDDA) and the saturation magnetization is61.69emu/g aftermodification, but still has superparamagnetism property. BSA is immobilized on thesurface of the magnetic nanoparticles by electrostatic adsorption. Successfulimmobilization of chiral selector BSA on the particles was confirmed by zetapotential, FTIR and TGA. The influence of PDDA concentration, BSA initialconcentration, pH and ion strength on the immobilization were investigated, and theoptimum immobilization capacity of the BSA is425.7mg/g at pH7.0. Theconformation and properties of the protein-functionalized magnetic nanoparticleswere characterized by TEM, XRD, VSM, zeta potential, TGA, FTIR, CD, ITC, FLand UV-vis spectroscopy. The protein-functionalized magnetic nanoparticles exhibitstereoselective adsorption for racemic ibuprofen. At pH7.0, the enantiomeric excess(e.e.) of the supernatant was determined by HPLC, after three stages of separation, ane.e. value of94.49%for the S-ibuprofen can be obtained in the supernatant fromracemic ibuprofen.