Interactions of the plant flavonoid fisetin with macromolecular targets: Insights from fluorescence spectroscopic studies

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.…”

Hydrogen Bonding on Photoexcitation

“…There have been some observations indicating that intramolecular hydrogen bonding competes with excited-state proton transfer, e.g. flavonoids while interacting with proteins, DNA and membranes [94]. However, the evidence for excited-state intermolecular hydrogen bonding is comparatively rare.…”

AVALIAÇÃO DE EFEITOS FÍSICO-QUÍMICOS NA EFICIÊNCIA DA BIOENCAPSULAÇÃO DE FLAVONOIDE LIPOSSOLÚVEL EM CÉLULAS DE LEVEDURA (Saccharomyces cerevisiae) ATRAVÉS DE CHOQUE OSMÓTICO

“…A fisetina (286 Da) é um flavonoide extraído de frutas como o morango, tomate, uva e pêssego, previamente apontado por sua capacidade de reduzir o avanço de células cancerígenas na próstata (Khan et al, 2008), auxiliar no tratamento de doenças neurodegenerativas (Maher, 2008) e reduzir o efeito de respostas inflamatórias pulmonares (Geraets et al, 2009). No entanto, devido a sua sensibilidade às alterações físico-químicas possui baixa biodisponibilidade in vivo (Sengupta et al, 2005). Neste caso é essencial envolver a molécula por uma membrana que seja capaz de impedir a sua degradação.…”