To assess how well the extracted metal-chelating groups were captured in compound libraries, substructure searches were carried out using two commercial chelator libraries, the Life Chemicals chelator focused library (6,428 compounds) and the Otava chelator fragment library (1,784 fragments), and two chemical spaces, WuXi AppTec GalaXi space (12 billion virtual products, 2023-03), Enamine Ltd REAL space (34 billion virtual products, 2022-11).