Enzymatic synthesis of sitagliptin intermediate using a novel ω-transaminase

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Enantiopure β-amino acids are essential precursors of various pharmaceuticals, agrochemicals and other industrially important chemicals. In this study, we selected sixteen potential ω-Transaminases (ω-TAs) by BLAST and phylogenetic tree analysis. These ω-TAs were cloned, purified and tested for their reactivity for the synthesis of model β-amino acid (<I>R</I>)-3-amino-4-(2,4,5-triflurophenyl) butanoic acid [3-ATfBA], a key precursor for sitagliptin. In an enzymatic cascade, lipase converted β-ketoester substrate to β-keto acid, which was subsequently aminated by the selected ω-TA to its corresponding β-amino acid. A potent enzyme from <I>Ilumatobacter coccineus</I> (ω-TAIC) was identified for the production of 3-ATfBA. The pH dependency of the product inhibition suggested that lowering the reaction pH to 7.0 can circumvent the inhibition of ω-TAIC by 3-ATfBA and about 92.3% conversion of 100 mM β-keto ester substrate could be achieved. The applicability of this enzymatic system was further evaluated at the scale of 140 mM, wherein 3-ATfBA was generated with excellent conversion (81.9%) and enantioselectivity (99% <I>ee</I>). Furthermore, ω-TAIC was successfully used for the synthesis of various β-amino acids from their corresponding β-keto ester substrates.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A potent ω-TA was identified using bioinformatic tools from 16 potential enzymes. </LI> <LI> 3-ATfBA was produced with good conversion (81.9%) and 99% <I>ee.</I> </LI> <LI> ω -TAIC was successfully used for the synthesis of various β-amino acids. </LI> <LI> Lowering the reaction pH to 7.0 can circumvent the inhibition of ω -TAIC by 3-ATfBA. </LI> </UL> </P>