IndolizinesHeterocyclic CompoundsThiophenesNitrogen CompoundsOrganic Chemistry PhenomenaThienopyridinesSpectrophotometry, InfraredIndicators and ReagentsPyrimidinesMolecular ConformationMagnetic Resonance SpectroscopyMolecular StructureSpectrophotometry, UltravioletPhotochemistryQuinolonesDrug Screening Assays, AntitumorStructure-Activity RelationshipCrystallography, X-RayModels, MolecularAntineoplastic Agents