Figure 1.

A: Fluorescence emission spectra (λ_ex = 380 nm), B: Fluorescence excitation spectra (λ_em = 530 nm) and C: Absorption spectra of fisetin (~ 7.5 μM) in presence of increasing concentrations of γ-cyclodextrin (0—, 1 ---, 5 –·–, 10 –··–, 20 –···–, 50 mM – – --). A_inset: Variation of the ratio of the intensity of tautomer vs normal isomers of fisetin (I_{T at 530} / I_{N at 470}) with increasing [γ-cyclodextrin].