Amination of Ketones by Employing Two New (S)‐Selective ω‐Transaminases and the His‐Tagged ω‐TA from Vibrio fluvialis

Abstract Two recently identified ( S )‐selective ω‐transaminases (ω‐TAs) that originate from Paracoccus denitrificans (Strep‐PD‐ωTA, cloned with an N ‐terminal Strep ‐tag II) and Pseudomonas fluorescens (PF‐ωTA) were employed for the asymmetric amination of selected prochiral ketones. The substrates tested were transformed into optically pure amines (>99 % ee ) with high conversion (up to >99 %). The ω‐TAs led to higher conversion in the absence of dimethyl sulfoxide as a cosolvent than in its presence (15 %, v/v). Additionally, it was shown that a His‐tagged recombinant transaminase from Vibrio fluvialis (His‐VF‐ωTA, cloned with an N ‐terminal His 6 ‐tag) showed for a single substrate, ethyl acetoacetate, significantly higher stereoselectivity for the amination compared to the corresponding commercial enzyme preparation (>99 vs. 50 %).