This article describes the discovery and characterization of FJMU1887, a novel brain-penetrant small-molecule inhibitor of Galectin-3 (Gal-3) identified through an AI-driven drug discovery platform. FJMU1887 demonstrated potent anti-inflammatory effects, reduced Aβ pathology, and improved cognitive function in Alzheimer's disease mouse models, highlighting its therapeutic potential for the treatment of Alzheimer's disease.