A NLRP3-inhibitory compound 7 (NIC7) and a potent derivative NIC7w are disclosed. NLRP3-inhibitory compound 7 (NIC7) and a potent derivative NIC7w are a novel small-molecule inhibitor for inhibiting NLRP3 inflammasomes are identified. These compounds inhibit main elements of the NLRP3 signaling pathway, primarily IL-1β and caspase 1, and improve cognitive behaviors of mice in Alzheimer disease mouse models. Compositions of NIC7 and NIC7w are suitable as a therapeutic agent in treating, preventing, or improving the conditions of Alzheimer's disease.