Sesquiterpene lactones from Ixeris sonchifolia Hance and their cytotoxicities on A549 human non-small cell lung cancer cells

Abstract

A new sesquiterpene lactone glucoside, 11,13-dihydroixerinoside (1), together with the five known sesquiterpene lactones, ixerinoside (2), ixerin Z (3), 11,13α-dihydroixerin Z (4), ixerin Z1 (5), and 3-hydroxydehydroleucodin (6), respectively, were isolated from the whole plants of Ixeris sonchifolia Hance. The compounds were identified by spectral analysis and comparison with spectroscopic data reported in the literatures. When the in vitro cytotoxic activities of compounds 1–6 were evaluated against A549 human non-small cell lung cancer cells, all six compounds exhibited cytotoxic activity against A549 cells, with compounds 2, 3, and 6 showing good activities (inhibitory concentration (IC₅₀ values < 30 μg/ml) that are comparable with well-established chemotherapeutic drug, 5-fluorouracil.

Keywords:

• Ixeris sonchifolia Hance
• sesquiterpene lactones
• cytotoxicity
• A549
• 11,13-dihydroixerinoside

Acknowledgements

This work was partially supported by grant 5R21CA115269 (K.-Y. Ng) from the NIH and a National University of Singapore Academic Research Fund R148-050-068-101 and R148-050-068-133 (K.-Y. Ng).