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

Abstract

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.

Graphical Abstract

Keywords:

• Opuntia Ficus indica
• opuntiol
• chemical characterization
• single crystal XRD
• NMR spectroscopy
• anticancer activity

Acknowledgements

The author greatly acknowledges the Indian Council of Medical Research (ICMR Letter:No. 45/21/2018/BMS/TRM), India for providing financial support in the form Senior Research Fellow to Mr. P. Veeramani kandan.

Disclosure statement

The authors declare that there are no conflicts of interest.

Figure 1. (a). ORTEP of opuntiol. (b). Hirshfeld surface mapped over (a) de, (b) di, (c) dnorm, and (d) curvedness form for opuntiol crystal. (C). 2 D fingerprint plots of crystal opuntiol (a) full; showing reciprocal contacts and resolved into: (b) C.C, (c) C.H, (d) C.O, (e) H.C, (f) H.H, (g) H.O, (h) O.C, (i) O.H, and (j) O.O, showing the percentage contribution to the Hirshfeld area of molecule.