Human adenosine A1 receptor (Target ChEMBL_ID: CHEMBL226, UniProt Accession: P30542) molecules with measured inhibition constant (Ki) were extracted from ChEMBL33 (6,966 compounds) and aggregated on Compound ChEMBL_ID calculating the median of pChEMBL values, where applicable. Compounds containing the 9Hpurine substructure (SMILES c1nc2cncnc2[nH]1) were then selected and used as the SAR dataset (1,032). Compounds were considered active when the annotated median pChEMBL value was greater than 7 (100nM).