hAChE-IN-8 (Compound S-12) is an orally active and selective inhibitor of hAChE, with an IC50 of 0.486 μM. It also inhibits BACE-1 with an IC50 of 0.542 μM, but shows negligible inhibition of Dyrk1A (IC50>10 μM). This compound reduces Aβ aggregation, exhibits good blood-brain barrier penetration, and is primarily used in Alzheimer's disease research.

AChE (human):0.486 μM, BCHE (human):0.542 μM, DYRK1A:>10 μM

hAChE-IN-8 at high concentrations (10-80 μM; 72 h) is non-toxic to SH-SY5Y neuroblastoma cells. At a concentration of 40 μM over 72 hours, hAChE-IN-8 significantly enhances the survival rate of SH-SY5Y cells under oxidative stress induced by Aβ1-42, while also restoring normal cell morphology. Additionally, hAChE-IN-8 demonstrates significant anti-Aβ aggregation activity at concentrations of 5-20 μM for 48 hours.

hAChE-IN-8 administered orally at doses of 500 and 1000 mg/kg as a single dose showed no toxicity or abnormal reactions in rats over a 14-day observation period. At doses of 2.5-10 mg/kg, hAChE-IN-8 improved scopolamine-induced memory loss in a dose-dependent manner and exhibited antioxidant potential, reversing ACh and AChE levels under oxidative stress conditions induced by scopolamine. When given once daily for 9 days at a dose of 10 mg/kg in an Aβ1-42-induced Alzheimer's disease model, it significantly improved cognition and reduced levels of AD-related proteins. In Drosophila, hAChE-IN-8 at concentrations of 10-200 μM in the culture medium showed no significant toxicity at lower concentrations but displayed some toxicity at higher concentrations. When tested at 10-20 μM in a Drosophila Alzheimer’s disease model, it effectively reversed Aβ42-induced eye phenotype changes, indicating notable neuroprotective effects. Additionally, at concentrations of 5-50 μM, it maintained high cell survival rates in larval cells at lower concentrations, but at higher concentrations, cell viability significantly decreased, displaying cytotoxic properties.