Some aspects of bioassay methods in natural-product research aimed at drug lead discovery

The objective of natural-product research aimed at drug lead discovery is to find unique bioactive molecules with improved biopharmaceutical properties or new modes of action. In order to discover such bioactive substances, different bioassays are used for detection, for guidance of the chemical isolation procedures and for preliminary biological characterization of new compounds, This article gives a brief update on current biological activities and discusses some essential, but occasionally neglected, aspects of bioassay methods. Some future perspectives on the use of bioassay methods in the drug-discovery process are also discussed.