S1RA (E-52862)

S1RA is a highly selective sigma-1 (σ1) receptor antagonist. It shows high affinity for σ1 receptors with Ki values of 17 nM and 23.5 nM for human and guinea pig σ1 receptors respectively but no significant affinity for the σ2 receptors with Ki values of 1000 nM and 9300 nM for guinea pig and rat σ2 receptors respectively. It shows moderate affinity (Ki = 328 nM) and antagonistic activity with low potency at the human 5-HT2B receptor. S1RA inhibits neuropathic pain in formalin-induced nociception and capsaicin-induced mechanical hypersensitivity in mice. Sigma receptor modulators may show activity against SARS-CoV-2 as sigma receptors interact with SARS-CoV-2 proteins Nsp6 and Orf9c.