Isolation and structure identification of bioactive natural compounds

Bruxelles Woluwe

Plant extracts having interesting in vitro and/or in vivo activities are subject to bio and chimio- guided fractionations to identify active components which could constitute new leads for further developments.





Fractions obtained by different chromatographic methods are evaluated and active ones analysed by LC-MS to identify well known compounds (based on retention times and MSn spectra, collaboration with MASSMET platform) and determine those which should be further purified (unidentified substances). Structural identification is based on UV, IR, SM, 1D and 2DNMR spectra.
In addition to known compounds, we identified several new molecules which are found for the first time in plants. Among them, we can point out diterpenes isolated from Croton zambesicus. Some of these diterpenes have been shown by our team to possess cytotoxic and pro-apoptoticproperties but others relax significantly rat aorta contracted by KCl. Comparison of the cytotoxic and vasorelaxant activities of isolated molecules and synthetic analoguesindicates that both effects are not linked. We can also cite several promising specific antiparasitic terpenic derivatives isolated form Keetia leucantha, Ocimum basilicum or Cymbopogon species. Identifications of antimalarial compounds is also guided by supervised metabolomicsstudies of crude extracts.