环氧基功能化SBA-15介孔分子筛的制备、表征及其固定化青霉素酰化酶

Synthesis and Characterization of Epoxy-functionalized SBA-15 and Application for the Immobilization of Penicillin G Acylase

利用表面嫁接法和乙烯基环氧化法制备了环氧基团功能化介孔分子筛G-SBA-15和O-SBA-15,并对其结构和表面性质进行了表征.结果表明,G-SBA-15和O-SBA-15均具有良好的长程有序结构,二者环氧基团的含量分别为0.78 mmol/g和0.37 mmol/g,在O-SBA-15表面还存在一定数量的乙烯基基团.G-SBA-15和O-SBA-15用于固定青霉素酰化酶(pen ic illin G acylase,PGA),固定化酶PGA/G-SBA-15和PGA/O-SBA-15在37℃时水解青霉素G钾制备6-氨基青霉烷酸(6-APA)的表观活性分别为1075 IU/g和1761 IU/g.PGA/G-SBA-15经4次使用后表观活性趋于稳定,经10次使用后保持其初始活性的83.7%.PGA/O-SBA-15在重复使用中,表观活性出现持续衰减,10次使用后保持其初始活性的51.6%,PGA/G-SBA-15的操作稳定性明显好于PGA/O-SBA-15.

Epoxy-functionalized SBA-15 mesoporous molecular sieves G-SBA-15 and O-SBA-15 were respectively synthesized by post grafting and epoxy oxidation of vinyl-SBA-15 and characterized by FT-IR, TG-DTA, XRD and N2 adsorption/desorption techniques. The results show that both retain a well-defined pore structure. The epoxy group content grafted on G-SBA-15 is 0.78 mmol/g. The O-SBA-15 possesses the epoxy group content of 0.37 mmol/g and considerable vinyl groups existing on its surface. The apparent activity of penicillin G acylase （PGA） immobilized on G-SBA-15 and O-SBA-15 were respectively 1075 IU/g and 1761 IU/g for hydrolyzing penicillin G potassium into 6-aminopeniciUanic acid （6-APA） at 37℃. The apparent activity became relatively steady as PGA/ G-SBA-15 used for 4 times and about 83.7 % of its initial activity was kept after 10 recycles. The apparent activity of PGA/O-SBA-15 displayed continuous decline in cycle uses and remained about 51.6 % of its initial activity after 10 recycles. PGA/G-SBA-15 exhibits better operational stability than that of PGA/O-SBA-15.