From resveratrol to trimethoxystilbene: HPLC and docking reveal enhanced inhibition of PDE1 and PDE4

Phosphodiesterases (PDEs) control cyclic nucleotide signaling and are established targets in inflammatory disease, with PDE1 and PDE4 being especially relevant for the regulation of cAMP. Here, we asked whether methylating the hydroxyl groups of resveratrol (RSV), which yields 3,4,5′-trimethoxy-trans-stilbene (TMS), improves its ability to inhibit these two isoenzymes.

Using an optimized HPLC assay that follows cAMP hydrolysis, we determined the kinetic and inhibition parameters of both enzymes. PDE4 showed a higher substrate affinity than PDE1. RSV proved to be a weak inhibitor, whereas TMS was approximately 4-fold (PDE1) and 8-fold (PDE4) more potent. The reference inhibitor roflumilast remained clearly superior, acting in the nanomolar range.

Molecular docking placed RSV, TMS and roflumilast in the same catalytic pocket, in contact with conserved residues such as glutamine. The higher potency of TMS can be explained by its better fit within the hydrophobic active site, which strengthens ligand–enzyme interactions.

These results show that trimethylation boosts the PDE-inhibitory capacity of resveratrol derivatives and point to TMS as a dual PDE1/PDE4 modulator, illustrating the value of combining experimental and computational approaches.