Pharmaceutical research is not just about molecules, it is about realizable molecules having certain properties. The available set of computable properties is growing, each function usually calculates a specific physicochemical parameter. These functions, like partial charge distribution, p , logD carry important chemical information, but the most interesting questions today are more complex. Many questions are related to ADMET. Will a planned specific compound be absorbed well, what are its major metabolites, how will it behave in a certain reaction, will it be biologically active? Scientists need an easy way to formulate calculations by the combination of property predictions,mathematical functions, and substructure matching functions. The Chemical Terms language was developed with this purpose in mind. More than a hundred functions are currently provided, and can be extended through a public plugin interface. The evaluator engine is an integratable component, which provides instant evaluation of Chemical Terms expressions entered as text. The Chemical Terms language has been used to improve the chemical feasibility of various cheminformatics tools such as database filtering, pharmacophore screening, drug design, virtual synthesis and metabolic pathway prediction. 8th International Conference on Chemical Structures (ICCS) · June 1-5, 2008 Download