The search for new lead compounds when no sufficient structural information on the receptor binding
site, neither on the binding mechanism, are available is challenging, but it can be proceeded if biological activity
data are provided for at least one active compound towards the target under consideration. In the recent years,
traditional approaches with respect to this situation such as QSAR and pharmacophore techniques have been
supplemented by 3D similarity search techniques to mine large banks of compounds, searching for small
compounds similar to the bioactive ones. We introduce some of the concepts related to the latter techniques, and
we discuss briefly foreseen developments.
