Another strategy to characterize the contents and diversity of compound databases is the use of molecular scaffolds or chemotypes i.e., the central or main core structure of a molecule . Like physicochemical properties, molecular scaffolds can be interpreted straightforwardly and facilitate communication within research groups from different disciplines. The concept of scaffold is associated with "scaffold hopping" and "privileged structures". Scaffold content analysis is frequently used to compare compound databases, uncover novel scaffolds in a compound data set, analyze the SAR of sets of molecules with measured activity, and analyze the SAR of sets of molecules with measured activity .