Simultaneous synthesis of enantiomerically pure (S)-amino acids and (R)-amines using α/ω-aminotransferase coupling reactions with two-liquid phase reaction system |
| |
Authors: | Byung-Kwan Cho Ho Jung Cho Hyungdon Yun Byung-Gee Kim |
| |
Affiliation: | Interdisciplinary Program for Biochemical Engineering and Biotechnology, School of Chemical Engineering, and Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, South Korea |
| |
Abstract: | An efficient simultaneous synthesis of enantiopure (S)-amino acids and chiral (R)-amines was achieved using α/ω-aminotransferase (α/ω-AT) coupling reaction with two-liquid phase system. As, among the enzyme components in the α/ω-AT coupling reaction systems, only ω-AT is severely hampered by product inhibition by ketone product, the coupled reaction cannot be carried out above 60 mM substrates. To overcome this problem, a two-liquid phase reaction was chosen, where dioctylphthalate was selected as the solvent based upon biocompatibility, partition coefficient and effect on enzyme activity. Using 100 mM of substrates, the AroAT/ω-AT and the AlaAT/ω-AT coupling reactions asymmetrically synthesized (S)-phenylalanine and (S)-2-aminobutyrate with 93% (>99% eeS) and 95% (>99% eeS) of conversion yield, and resolved the racemic α-methylbenzylamine with 56% (95% eeR) and 54% (96% eeR) of conversion yield, respectively. Moreover, using 300 mM of 2-oxobutyrate and 300 mM of racemic α-methylbenzylamine as substrates, the coupling reactions yielded 276 mM of (S)-2-aminobutyrate (>99% ee) and 144 mM of (R)-α-methylbenzylamine (>96% ee) in 9 h. Here, most of the reactions take place in the aqueous phase, and acetophenone mainly moved to the organic phase according to its partition coefficient. |
| |
Keywords: | Aminotransferase Coupling reaction Chiral amino acids Amines Two-liquid phase reaction |
本文献已被 ScienceDirect 等数据库收录! |
|