New roxadustat amino acid drug conjugation derivatives: molecular docking, molecular dynamics simulation and in vitro assay

Abstract

In this study, a series of novel amino acid drug conjugates (ADCs) of roxadustat were designed to inhibit the prolyl hydroxylase domain (PHD) enzyme. We introduce new amide-based derivatives aimed at improving pharmacological properties such as solubility and reducing side effects, as evaluated through IC₅₀ testing. To achieve this, six new compounds were synthesized by forming a bond between the amino (–NH₂) group of an amino acid and the carboxyl (–COOH) group of roxadustat using solid-phase peptide synthesis (SPPS) with the Fmoc strategy. The resulting derivatives were obtained with high purity and yield, without the need for further purification. To explore the molecular mechanism of roxadustat and its derivatives, molecular docking, molecular dynamics (MD) simulations, post-MD analyses, and binding free energy calculations were performed. MD results indicated that most of the new derivatives exhibited higher binding affinity for the protein active site compared to roxadustat, with the roxadustat–Gly derivative showing the highest affinity among them.