Isolation and characterization of opuntiol from Opuntia Ficus indica (L. Mill) and its antiproliferative effect in KB oral carcinoma cells

In this study, we isolated and characterized a novel bioactive flavonol from the cactus pad of Opuntia Ficus indica Indica (L. Mill) (OFI) by chromatography techniques. The isolated compound was characterized by FT-IR, 1H and 13C NMR spectroscopy. Single-crystal XRD results illustrate that the obtained flavonol was opuntiol (6-hydroxymethyl-4-methoxy-2H-pyran-2-one) and it was found to be near planar except for the H atoms of the methylene and methyl groups. The crystal packing was stabilized by C-H….O and O-H….O intermolecular hydrogen bonds. The isolated opuntiol significantly inhibited KB cells proliferation and its IC50 value was found to be 30 µM. Further, we noticed that opuntiol significantly induced ROS generation and subsequently altered MMP in KB cells. Western blot analysis and morphological observations by fluorescence microscope indicate the apoptotic inducing potential of opuntiol in KB cells.