Molecular Similarity as a Foundation and Caveat of Virtual Screening

In addition to the two major categories of LEVS approaches, similarity searching and compound classification, database filtering techniques should also be added to the virtual screening spectrum. Rule-based filters that screen databases for compounds with desired (e.g., drug- or leadlike) or undesired (toxicity and instability) molecular properties are widely used, not to identify individual active compounds but rather to reduce the size of screening databases as much as possible for further studies using more sophisticated methods. 

Molecular Similarity as a Foundation and Caveat of Virtual Screening 

---