Fisetin (3,7,3',4'-tetrahydroxyflavone) and quercetin (3,5, 7,3',4'-pentahydroxyflavone ) are the bioactive plant flavonoids of immense importance as potentially useful therapeutic drugs, for various free radical mediated as well as other diseases. 3-hydroxy flavone (3HF) and 7-hydroxy flavones (7HF) are synthetic compounds which are the chromophores of fisetin and quercetin. We have exploited dual luminescence property of fisetin, quercetin along with 3-HF and 7HF to examine their interactions with relevant macromolecular targets, namely double stranded (from calf thymus, CT), and quadruplex (G4) as well as i-motif (C4) DNAs. In the presence of DNA dramatic changes are observed in the intrinsic fluorescence behaviour of fisetin, quercetin, 3HF and 7HF. Spectroscopic, chromatographic studies reveal differences in binding behaviors with target DNAs for natural and synthetic flavonoids. Circular dichroism, differential absorption and size exclusion chromatophic studies indicated the formation of unusual DNA structures for the G and C rich DNAs. The spectroscopic studies on flavonol�DNA interactions described herein, demonstrate a powerful approach exploiting the highly sensitive intrinsic fluorescence properties of the flavonoids as their own ''reporter'' for probing and characterizing its interactions with macromolecular targets.

Flavonoids as duplex and quadruplex DNA ligands: Biophysical studies

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.