Abstract

Esomeprazole with chiral sulfoxides structure is used to treat gastric ulcer disease. Soybean pod shell peroxidase (SPSP) is a peroxidase extracted from soybean pods shells which are one of the most abundant natural resources in the world. In the production of chiral sulfoxides catalyzed by SPSP, it is very important to establish the reaction kinetic model and explore the reaction mechanism for the development of the process, however, there is no report on the establishment of the model. Asymmetric sulfoxidation reactions catalyzed by SPSP in water-in-oil microemulsions were carried out, and the King-Altman approach was used to establish a kinetic model. A yield of 91% and e.e. value of 96% for esomeprazole were obtained at the activity of SPSP of 3200 U ml-1 and 50 °C for 5 h. The mechanism with a two-electron reduction of SPSP-I is accompanied with a single-electron transfer to SPSP-I and nonenzymatic reactions, indicating that three concomitant sub-mechanisms contribute to the asymmetric oxidation involving five enzymatic and two nonenzymatic reactions, which can represent the asymmetric sulfoxidation of organic sulfides to form enantiopure sulfoxides. With 5.44% of the average relative deviation, a kinetic model fitting experimental data was developed. The enzymatic reactions may follow ping-pong mechanism with substrate inhibition of H2 O2 and product inhibition of esomeprazole, while nonenzymatic reactions follow a power law. Those results indicate that SPSP with a lower cost and higher thermal stability may be used as an effective substitute for horseradish peroxidase.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.