Synthesis and anti-acute ischemic stroke effect of quinazoline-benzothiazole RIPK1 inhibitors

Receptor-interacting protein kinase 1 (RIPK1) inhibitors show considerable translational potential for the treatment of neurodegenerative diseases; however, limited literature exists regarding their application in acute ischemic stroke (AIS). In this study, through structural modification, we designed and synthesized a series of RIPK1 inhibitors based on a benzothiazole-quinazoline core scaffold. Twenty compounds exhibited potent RIPK1 kinase inhibitory activity (IC₅₀ < 100 nM), and five of these demonstrated remarkable anti-necroptotic efficacy at the cellular level (EC₅₀ < 20 nM). Among them, compound 2 showed the lowest cytotoxicity and a suitable in vitro half-life. Further investigation revealed that the optimized compound 2 protected cells from necroptosis by inhibiting the phosphorylation and activation of the RIPK1-RIPK3-MLKL pathway. In a middle cerebral artery occlusion (MCAO) rat model, compound 2 significantly improved neurological function scores, reduced cerebral infarct volume, ameliorated serum biochemical profiles, and exhibited low acute toxicity in mice. These results indicate that compound 2 is a potent RIPK1 inhibitor with potential as a therapeutic agent for AIS.