Opposite Enantioselectivity in the Bioreduction of (<i>Z</i>
)-β-Aryl-β-cyanoacrylates Mediated by the Tryptophan 116 Mutants of Old Yellow Enzyme 1: Synthetic Approach to (<i>R</i>
)- and (<i>S</i>
)-β-Aryl-γ-lactams
作者:Elisabetta Brenna、Michele Crotti、Francesco G. Gatti、Daniela Monti、Fabio Parmeggiani、Robert W. Powell、Sara Santangelo、Jon D. Stewart
DOI:10.1002/adsc.201500206
日期:2015.5.26
The Trp 116 mutants of Old Yellow Enzyme 1 that catalyse the reduction of (Z)‐β‐aryl‐β‐cyanoacrylates give the opposite enantioselectivity according to the nature of the amino acid in position 116. Small amino acids (e.g., alanine) make the substrate bind to the enzyme′s active site in a “classical” orientation, affording the (S)‐enantiomer of the reduced product. When the size of the amino acid increases
老黄酶1的Trp 116突变体催化(Z)-β-芳基-β-氰基丙烯酸酯的还原反应,根据116位氨基酸的性质给出相反的对映选择性。底物以“经典”方向与酶的活性位点结合,提供还原产物的(S)-对映异构体。当氨基酸大小增加(例如亮氨酸)时,底物会采用“翻转”结合模式,该模式会转换为相应的(R)衍生物。对于大块氨基酸(例如,野生型色氨酸),不会发生还原反应。如此制备的对映体富集的氰基丙酸酯可转化为相应的(S)-和(R)-β-芳基-γ-内酰胺类化合物,通过顺序单锅法中的简单官能团互变,属于抑制性神经递质的前体,属于γ-氨基丁酸类。