Speaker
Description
Background: The synthesis of human drug metabolites (HDMs) is one of the fundamental aspects in pharmacokinetic and pharmacodynamic safety studies, as the U.S. Food and Drug Administration (FDA) requires evaluation of metabolites formed exceeding 10% systemic exposure of the parent drug. Conventional chemical synthesis of HDMs is often limited by low yields and complex procedures, highlighting the need for efficient alternatives (U.S. Food and Drug Administration, 2008). Enzymatic transformation of pharmaceuticals provides an effective route for metabolite synthesis.
Methods: We characterized a fungal unspecific peroxygenase (UPO) from Daldinia sp. (DspUPO), a heme-thiolate enzyme with functional similarities to cytochrome P450s. This enzyme was employed to produce HDMs from several drugs and natural compounds using hydrogen peroxide as the oxidant. The resulting HDMs were identified by GC–MS and HPLC analyses.
Results: Structural analysis of DspUPO’s active site, combined with site-directed mutagenesis, revealed key residues that modulate substrate binding and the HDMs production rate by DspUPO. Using this enzyme, several metabolites were generated from drugs including atorvastatin, fluvastatin, and niclosamide, as well as from natural compounds such as phloretin, naringenin, and resveratrol.
Conclusions: DspUPO represents a promising biocatalyst for scalable and cost effective enzymatic production of HDMs and natural compounds, offering the advantage of utilizing hydrogen peroxide as an alternative to NADPH.
Acknowledgments:
This research was supported by the National Research Foundation of Korea (NRF) (No. RS-2021-NR059615); the Bio&Medical Technology Development Program (MSIT) (No. RS-2024-00440681); and the Korea National Institute for International Education (GKS-G).
