α-Synuclein inhibitor 9 (Compound 20C) is a molecule that targets and binds to cavities within mature α-synuclein fibrils, diminishing their β-sheet content. It effectively inhibits the aggregation of A53T α-synuclein and exhibits neuroprotective properties, enhancing brain functionality and alleviating motor impairments. This compound is utilized in research related to Parkinson's disease (PD). [1]