pb-28

σ2 receptor agonist

PB28 is a cyclohexylpiperazine derivative that functions as a potent and highly selective agonist of the sigma 2 (σ2) receptor, exhibiting a Ki (binding affinity) of 0.68 nM. At the same time, PB28 acts as an antagonist of the sigma 1 (σ1) receptor, with a Ki of 0.38 nM. PB28 demonstrates a lower affinity for other receptors. It effectively inhibits electrically evoked twitch in both the guinea pig bladder (EC50 value of 2.62 μM) and ileum (EC50 value of 3.96 μM). Moreover, PB28 exhibits the ability to modulate protein-protein interaction between SARS-CoV-2 and human cells. Additionally, PB28 triggers caspase-independent apoptosis and possesses significant antitumor activity.