From virtuality to reality - Virtual screening in lead discovery and lead optimization: a medicinal chemistry perspective.

Drug discovery and development is an interdisciplinary, expensive and time-consuming process. Scientific advancements during the past two decades have altered the way pharmaceutical research produces novel bio-active molecules. Advances in computational techniques and hardware solutions have enabled in silico methods, and in particular virtual screening, to speed up modern lead identification and lead optimization. Recent successes have proven the power of combining virtual screening with complementary and synergistic biophysical methods, such as X-ray crystallography, NMR spectroscopy and isothermal titration calorimetry (ITC). This review addresses key issues, challenges and recent improvements of virtual screening methods and strategies. Examples highlighting the impact of an integrated virtual screening and biophysical characterization platform in the lead identification and optimization process are presented and discussed.