RIPK1-IN-34 is a selective RIPK1 inhibitor capable of penetrating the blood-brain barrier with an IC50 of 126.70 nM, showing minimal inhibition of RIPK3 (IC50 > 10,000 nM). It exerts significant neuroprotective effects by inhibiting the phosphorylation of RIPK1, RIPK3, and mixed lineage kinase domain-like pseudokinase (MLKL) in the necroptosis pathway. RIPK1-IN-34 demonstrates neuroprotective effects in rat models of middle cerebral artery occlusion (MCAO) and is a candidate for research in the treatment of acute ischemic stroke (AIS).

RIPK1:126.7 nM

RIPK1-IN-34 (Compound 9b) significantly reduces TNF-α (T), Smac mimetic SM-164 (S), and Z-VAD-FMK (Z) induced apoptosis in HT-29 (EC50 = 71.61 nM) and HT-22 (EC50 = 38.45 nM) cells. RIPK1-IN-34, at concentrations ranging from 0.78 to 400 nM over 24 hours, effectively counters TSZ-induced apoptosis in HT-29, U937, L929, and HT-22 cells, restoring them to near the state of untreated controls. Additionally, RIPK1-IN-34 (1, 10, 100 nM, 4.5 hours) provides significant protection against necroptosis in L929 cells. It also inhibits the phosphorylation of RIPK1, RIPK3, and MLKL in L929 cells in a dose-dependent manner at concentrations between 0 to 1000 nM over 4.5 hours.

RIPK1-IN-34 (Compound 9b), administered intravenously at doses of 0.5-4.5 mg/kg twice, shows a dose-dependent improvement in neurological function in SD rats, reduces cerebral infarct volume, and inhibits inflammation and oxidative stress, demonstrating significant neuroprotective effects. At doses of 78.4-160 mg/kg administered intraperitoneally twice with an interval of one hour, RIPK1-IN-34 does not cause acute toxicity in C57BL/6 mice, with an LD50 exceeding 160 mg/kg, indicating a high level of safety.