Screening potential antitumor agents from natural plant extracts by G-quadruplex recognition and NMR methods.

Weeding out ligands: Rapid screening of G-quadruplex ligands in plant extracts is achieved by the combination of G-quadruplex recognition (see picture) with 1H NMR spectroscopy, diffusion-ordered spectroscopy (DOSY), and 2D NMR techniques. The method has a low detection limit and allows the structures of the ligands to be identified.