Department of Chemistry - PhD Seminar - Exploring the Chemistry and Biology of Haloperoxidases

Student: Ms. ZHOU Yiqin

Department: Department of Chemistry, HKUST

Supervisor(s): Professor TONG Rongbiao

Abstract

This seminar will explore haloperoxidases as powerful biocatalytic tools for selective organic transformations, addressing key challenges in modern synthetic chemistry. Haloperoxidases represent a unique class of enzymes that utilize hydrogen peroxide to oxidize halide ions, generating reactive halogenating species under mild, environmentally benign conditions.

The presentation will cover two major enzyme families: heme-dependent haloperoxidases and vanadium-dependent haloperoxidases from marine organisms. Through detailed mechanistic analysis supported by spectroscopic evidence and crystallographic data, attendees will understand how these enzymes achieve remarkable selectivity that surpasses traditional chemical methods.

Key synthetic applications to be discussed include asymmetric sulfoxidation (featuring the industrial synthesis of esomeprazole), selective aromatic halogenation, alkene epoxidation, and recent applications in total synthesis. The seminar will highlight successful case studies where haloperoxidases have been integrated into complex synthetic routes, demonstrating their practical utility beyond academic curiosity.

The presentation will address both the advantages (exquisite selectivity, mild reaction conditions, green chemistry principles) and current limitations (substrate scope, scalability challenges, enzyme stability) of haloperoxidase technology. Current research directions, including protein engineering approaches and flow chemistry integration, will be presented as future opportunities.

This seminar aims to equip organic chemistry researchers with practical knowledge of when and how to consider haloperoxidases as viable alternatives to traditional halogenation methods, contributing to more sustainable and selective synthetic methodologies