These materials are an alpha-synuclein binding compound (standard), and the precursor for PET radiolabeling the compound. Precursor’s code name: TZ61-23; chemical name: 2-((6-methoxypyridin-3-yl)amino)quinolin-6-ol. Standard’s code name: TZ61-44; chemical name: 6-(2-fluoroexthoxy)-N-(6-methoxypyridin-3-yl)quinolin-2-amine.