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.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Naringenin-7-O-glucoside [Prunin (Pru)], isolated from the fruit shell of the medicinal plant, Bixa orellana L. forms a 1:1 inclusion complex with cyclomaltoheptaose (β-cyclodextrin, β-CD) β-CD covers the guest molecule partially and allows its binding with calf thymus DNA (ctDNA) in host–guest complex form. ► It is speculated that extraction of Pru from DNA by β-CD occurs for the forming inclusion complex. ► There were morphological differences between Prunin and its complex with ctDNA in the presence and the absence of cyclodextrin.