Cytotoxic and antibacterial xanthones from the roots of Maclura cochinchinensis

Abstract

Three new furanoxanthones, macochinxanthones A–C (1–3) and sixteen known xanthones (4–19) were isolated from the roots of Maclura cochinchinensis. Their structures were elucidated by spectroscopic analysis including NMR, UV and IR, as well as mass spectrometry. Chiral-phase HPLC analysis of 1–3 revealed that they were scalemic mixtures with an enantiomeric excess (ee) of 0.05%, 36.8% and 8%, respectively. Most of the isolated xanthones exhibited potent cytotoxicity against four cancer cell lines (KB, HelaS3, A549 and HepG2) with IC₅₀ values in the range of 1.29–90.15 µM. In addition, many of them displayed antibacterial activity against Gram-positive bacteria and Methicillin resistant Stephylococus aureus (MRSA) with MIC values in the range of 4–128 µg/mL.

Graphical Abstract

Keywords:

• Maclura cochinchinensis
• Moraceae
• xanthones
• macochinxanthones A–C
• cytotoxicity
• antibacterial
• MRSA

Acknowledgements

This work is dedicated to our best friend, the late Dr. Pongpan Siripong, who worked on medicinal plants for preventing and treating cancer for her whole life at the National Cancer Institute, Bangkok Thailand.

We thank Dr.Charun Radchanui, Pattani Fisheries and Agriculture Technology College, and Miss Supag Aonthong, Yala Vocational College, Thailand, for providing the plant sample. We thank Assoc. Prof. Sophon Boonlue, Department of Microbiology, Faculty of Science, Khon Kaen University, Thailand for providing bacterial culture and laboratory facilities. We would also like to thank Mr. Ian Thomas for linguistic corrections. We acknowledge the Center of Excellence for Innovation in Chemistry (PERCH-CIC) for partial support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was funded by a scholarship under the Post-doctoral Program from Research Affairs and Graduate School, Khon Kaen University (Grant No. 58228-3) for W.L.