RAPID DETECTION AND SUBSEQUENT ISOLATION OF BIOACTIVE CONSTITUENTS OFCRUDE PLANT-EXTRACTS

Rapid detection of biologically active natural products plays a strate gical role in the phytochemical investigation of crude plant extracts. In order to perform an efficient screening of the extracts, both biol ogical assays and HPLC analysis with various detection methods are use d. Combined techniques such as HPLC coupled to UV photodiode array det ection (LC/UV) and to mass spectrometry (LC/MS or LC/MS/MS) provide us eful structural information on the metabolites on-line prior to isolat ion. The recent introduction of HPLC coupled to nuclear magnetic reson ance (LC/NMR) represents a powerful complement to the LC/UV/MS screeni ng. Various plants belonging to the Gentianaceae and Leguminosae famil ies have been analysed by LC/UV, LC/MS, LC/MS/MS, and LC/NMR. The use of all these coupled techniques allows the structural determination of known plant constituents rapidly and with only a minute amount of pla nt material. With such an approach, the time-consuming isolation of co mmon natural products is avoided and an efficient targeted isolation o f compounds presenting interesting chemical or biological features can be performed.