G-quadruplexes are believed to have important biological functions, so many small molecules have been screened or developed for targeting G-quadruplexes. However, it is still a major challenge to find molecules that recognize specific G-quadruplexes. Here, by using a combination of surface plasmon resonance, electrospray ionization mass spectrometry, circular dichroism, Western blot, luciferase assay, and reverse transcriptase stop assay, we observed a small molecule, namely, oxymatrine (OMT) that could selectively bind to the RNA G-quadruplex in 5′-untranslated regions (UTRs) of human vascular endothelial growth factor (hVEGF), but could not bind to other G-quadruplexes. OMT could selectively repress the translation of VEGF in cervical cancer cells. Furthermore, it could recognize VEGF RNA G-quadruplexes in special conformations. The results indicate that OMT may serve as a potentially special tool for studying the VEGF RNA G-quadruplex in cells and as a valuable scaffold for the design of ligands that recognize different G-quadruplexes.

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A tetraphenylethene derivative: 1,1′,1′′,1′′′-(((ethene-1,1,2,2-tetrayltetrakis(benzene-4,1-diyl)) tetrakis(oxy)) tetrakis(butane-4,1-diyl)) tetrakis(4-(dimethylamino) pyridin-1-ium) bromide (TPE-B) has been designed as a fluorescent light-up probe with high selectivity for parallel G-quadruplexes