Enzymatic Preparation of the Chiral (S)-Sulfoxide Drug Esomeprazole at Pilot-Scale Levels

Abstract

Esomeprazole is the most popular proton pump inhibitor (PPI) for treating gastroesophageal reflux disease. Enzymatic asymmetric sulfoxidation is a green approach to produce chiral sulfoxides. In this report, we focused on optimizing asymmetric sulfoxidation catalyzed by prazole sulfide monooxygenase (AcPSMO). The costly redox cofactor NADPH utilized by AcPSMO was regenerated by formate dehydrogenase with CO 2 as the coproduct, which can be removed easily. During the scale-up process, oxygen supply was found to be the main limiting factor during the early phase of the reaction, while the instability of AcPSMO and the lack of the cofactor NADPH hindered progress during the middle and late phases of the 0.6 L reaction. Finally, by adjusting oxygen mass transfer and increasing the dissolved oxygen, the enzymatic reaction was stepwise amplified to a 120 L scale using a 300 L thermostatic stirred reactor, affording 95.9% conversion and 99.9% enantiomeric excess after 12 h. Extraction and refinement of the product resulted in 0.39 kg of the isolated esomeprazole (sodium salt), with 57.8% overall yield (73.4% before the salt-forming reaction) and 99.1% purity. Thus, a green-by-design system was constructed for the efficient and precise oxidation of omeprazole sulfide into esomeprazole with molecular O 2 as the green cosubstrate and CO 2 and H 2 O as byproducts.

Identification of a novel ene reductase from Pichia angusta with potential application in (R)-levodione production

“…This result can be attributed to the high K m value of PaER towards NADPH and the degradation of NADP(H). 22 …”

Properties and Mechanisms of Flavin-Dependent Monooxygenases and Their Applications in Natural Product Synthesis

“…In 2019 [ 133 ] and 2020 [ 134 ], Zhang et al successively modified the cyclohexanone monooxygenase (AcCHMO) in Acinetobacter calcoaceticus by structure-based protein engineering method to a pyrmet-azole monooxygenase that can catalyze the oxidation of pyrmet-azole to esomeprazole, and named it AcPSMO. Some limiting factors encountered in the scale-up of the modified reaction were studied, and then the biological oxidation reaction was scaled up in a step-by-step manner for the preparation of esomeprazole [ 15 ].…”

Secretory expression of cyclohexanone monooxygenase by methylotrophic yeast for efficient omeprazole sulfide bio-oxidation

“…Bio-asymmetric synthesis of (S)-omeprazole by utilizing CHMO Acineto -Mut-P in the yeast secretion was then conducted. The Burkholderia stabilis 15516 formate dehydrogenase (BstFDH) (Xu et al 2020;Hatrongjit and Packdibamrung 2010) was coupled for the regeneration of the cofactor NADPH. In the initial set of experiments, moderate rates (65-86%) of pyrmetazole conversion were observed within 17 h (Table 3, entries 1, 2).…”