Abstract

Fe₃O₄ magnetic nanoparticles were prepared by chemical co-precipitation and modified with 3-aminopropyltriethoxysilane (APTES) and CS₂ to form Fe₃O₄-APTES-CS₂ magnetic carriers. Magnetically immobilized enzymes are attractive owing to their potential applications in many biological fields. When an alternating magnetic field is applied, the magnetic nanoparticles experience a force in the direction of the field, and the magnetic moments of the magnetic nanoparticles are apt to align in the direction of the field. Thus, magnetic nanoparticles behave like microscopic stirrers. The optimal reaction conditions of the acylation reaction using Fe₃O₄-APTES-CS₂-lipase were 200 mmol/L 1-methyl-3-amphetamine, 100 mg immobilized lipase, 200 μL ethyl acetate, 12.6 × g rotating speed, 40 °C, and 5 days in the shaker. The conversion and enantiomeric excess of R-2a reached a maximum of 36.8% and 98.5%, respectively. 1-Methyl-3-phenylpropylamine was resolved using Fe₃O₄-APTES-CS₂-lipase in an alternating magnetic field. The optimal magnetic field frequency and magnetic field intensity were determined to be 500 Hz and 12 Gs, respectively. The conversion and enantiomeric excess of R-2a reached a maximum of 40.3% and 98.5%, respectively. The results revealed that conversion under a magnetic field was significantly higher than that without a magnetic field. Highly optically active (R)-N-acetyl-1-methyl-3-amphetamine can be obtained via an efficient resolution of racemic 1-methyl-3-phenylpropylamine with immobilized lipase magnetic nanoparticles as a catalyst and ethyl acetate as an acyl donor in organic solvents in an alternating magnetic field.

摘要

采用化学共沉淀法制备Fe ₃ O _{4磁性纳米粒子，并用3-氨基丙基三乙氧基硅烷(APTES)和CS 2}改性形成Fe ₃ O ₄ -APTES-CS ₂磁性载体。磁性固定酶因其在许多生物领域的潜在应用而具有吸引力。当施加交变磁场时，磁性纳米粒子受到磁场方向的力，磁性纳米粒子的磁矩倾向于沿磁场方向排列。因此，磁性纳米粒子的行为类似于微型搅拌器。_{Fe 3} O ₄酰化反应的最佳反应条件-APTES-CS ₂ -脂肪酶为200 mmol/L 1-甲基-3-苯丙胺、100 mg固定化脂肪酶、200 μL乙酸乙酯、12.6×  g转速、40℃、5天摇床。R-2a 的转化率和对映体过量分别达到最大值 36.8% 和 98.5%。_{使用 Fe 3} O ₄ -APTES-CS ₂拆分 1-甲基-3-苯丙胺-交变磁场中的脂肪酶。最佳磁场频率和磁场强度分别确定为 500 Hz 和 12 Gs。R-2a 的转化率和对映体过量分别达到最大值 40.3% 和 98.5%。结果表明，磁场下的转化率明显高于没有磁场的转化率。以固定化脂肪酶磁性纳米粒子为催化剂，乙酸乙酯为酰基供体，高效拆分外消旋的 1-甲基-3-苯丙胺，可获得高光学活性的 (R)-N-乙酰基-1-甲基-3-苯丙胺。交变磁场中的有机溶剂。