Cytotoxicity and nitric oxide inhibitory activities of Xanthones isolated from Calophyllum hosei Ridl.

Abstract

Previous studies on Calophyllum species have shown the existence of a wide variety of bioactive xanthones and coumarins. Phytochemical investigations carried out on the plant, Calophyllum hosei led to the isolation of eleven known xanthones, ananixanthone (1), 9-hydroxycalabaxanthone (2), dombakinaxanthone (3), thwaitesixanthone (4), caloxanthone B (5), trapezifolixanthone (6), β-mangostin (7), osajaxanthone (8), caloxanthone A (9), calozeyloxanthone (10) and rubraxanthone (11). The structures of these compounds were identified and elucidated using spectroscopic techniques such as NMR and MS. The cytotoxicity and nitric oxide production inhibitory activities of selected xanthones as well as the extracts were tested against HL-60 cells and RAW 264.7 murine macrophages, respectively. Among all tested compounds, β-mangostin exhibited appreciable cytotoxicity against HL-60 cells with the IC₅₀ value of 7.16 ± 0.70 µg/mL and rubraxanthone exhibited significant nitric oxide inhibitory activity against LPS induced RAW 264.7 murine macrophages with the IC₅₀ value of 6.45 ± 0.15 µg/mL.

Graphical Abstract

Keywords:

• Calophyllum hosei
• xanthones
• rubraxanthone
• cytotoxicity

Acknowledgments

The authors express gratitude for the financial support from Universiti Putra Malaysia and MOSTI under the Agri Science Fund as well as Centre for Drug Research and Universiti Sains Malaysia for providing research facilities and technical support. The Sarawak Biodiversity Centre (SBC) is acknowledged.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

The financial support from MOSTI under the Agri Science Fund as well as from Universiti Putra Malaysia.