Influence of different environments on the excited-state proton transfer and dual fluorescence of fisetin

Interaction of flavonoids with red blood cell membrane lipids and proteins: Antioxidant and antihemolytic effects

“…3-HF and fisetin are well-known molecular systems exhibiting excited state intramolecular proton transfer (ESIPT) and dual fluorescence behavior [35][36][37][38][39]. On the other hand, flavonoids containing a 5-OH group (e.g.…”

“…While dual fluorescence behavior (consisting of blue-violoet and green fluorescence bands) is observed for both 3-HF and fisetin, the spectra are much less resolved in the latter case. The large Stokes shifted green fluorescence band of fisetin can be assigned to emission from the tautomer species generated by an intramolecular ESPT process whereas the blue-violet fluorescence can be assigned to the S 1 → S 0 normal (non-proton transferred) emission, with notable charge transfer characteristics [6,38,39]. Interestingly in contrast to 3-HF, where strong enhancement of the green tautomer emission is observed upon incorporation in RBC ghost membranes, only a slight increase in the relative yield of this band occurs in case of fisetin in such environment.…”

“…In case of the strongly fluorescent flavonoids (viz. 3-HF and fisetin) the occurrence of FRET is clearly manifested by the quenching in the tryptophan (donor) fluorescence with concomitant appearance of characteristic excited state proton transfer (ESPT) emission bands [35,39] of the flavonoids (acceptor) (Fig. 4).…”

Preparation and Electrochemical Study of Fisetin Modified Glassy Carbon Electrode. Application to the Determination of NADH and Ascorbic Acid

“…It has been claimed that fisetin posses a broad spectrum of biological activities and important therapeutic applications [25,26]. Some spectrochemical [27], analytical [28,29] and biological [30 -35] properties of fisetin were reported in the literatures. However, no report has been published hitherto concerning its use as a modifier in the preparation of CMEs or as a catalyst in the catalysis of slow reactions.…”

Making sense of luminescence from GRAS optical probes

“…Bottom -relation between the difference in peak wavelength (Dl em ) of the two characteristic emission bands and a w . [42,43]. Recent work indicates that fisetin emission is also sensitive to water activity.…”