Currently, there is a significant unmet need for novel analgesics with fewer side effects. In this study, we carried out structural modification of a hit compound previously identified in an artificial-intelligence (AI) virtual screening and discovered the potent analgesic, benzo[b]thiophene-2-carboxamide analog (compound 25) with new structural scaffold. We investigated the signaling pathways of opioid receptors mediated by compound 25, and found this racemic compound activated mu-opioid receptor through the cyclic adenosine monophosphate (cAMP) and β-arrestin-2-mediated pathways with strong potency and efficacy, and accompanying nociceptin-orphanin FQ opioid peptide and delta-opioid receptors through the cAMP pathway with weak potencies. Compound 25 elicited potent antinociception in thermal-stimulated pain (ED₅₀ value of 127.1 ± 34.65 μg/kg) and inflammatory-induced allodynia models with less gastrointestinal transit inhibition and antinociceptive tolerance than morphine. Overall, this study revealed a novel analgesic with reduced risks of side effects.

目前，对具有较少副作用的新型镇痛剂存在显着未满足的需求。在这项研究中，我们对先前在人工智能 (AI) 虚拟筛选中发现的命中化合物进行了结构修饰，并发现了具有新结构支架的强效镇痛剂苯并[b]噻吩-2-甲酰胺类似物（化合物25 ）。我们研究了化合物25介导的阿片受体信号通路，发现这种外消旋化合物通过环磷酸腺苷 (cAMP) 和 β-arrestin-2 介导的通路激活 mu-阿片受体，具有很强的效力和功效，并伴随着伤害感受素- orphanin FQ 阿片肽和 δ-阿片受体通过 cAMP 通路，效力较弱。化合物25在热刺激疼痛（ED ₅₀值为 127.1 ± 34.65 μg/kg）和炎症诱导的异常性疼痛模型中引起有效的镇痛作用，其胃肠道转运抑制和镇痛耐受性低于吗啡。总体而言，这项研究揭示了一种降低副作用风险的新型镇痛剂。