Isolation of Prunin from the fruit shell of Bixa orellana and the effect of β-cyclodextrin on its binding with calf thymus DNA.

Naringenin-7-O-glucoside [Prunin (Pru)] was isolated from the fruit shell of Bixa orellana L. The binding of Pru with calf thymus DNA (ctDNA) and the influence of cyclomaltoheptaose (β-cyclodextrin, β-CD) on the binding were studied by absorption and fluorescence spectroscopic techniques. The comparison of the binding modes of Pru/β-CD and ctDNA-Pru/β-CD suggested that β-CD extracted Pru from DNA for forming inclusion complex. Molecular modeling gave added support to the above results. Fluorescence microscopy was used to visualize the effect of β-CD on the bindings.