A new chromanone acid from the stem bark of Calophyllum teysmannii

Abstract

A new chromanone acid, namely caloteysmannic acid (1), along with three known compounds, calolongic acid (2), isocalolongic acid (3) and stigmasterol (4) were isolated from the stem bark of Calophyllum teysmannii. All these compounds were evaluated for their cytotoxic and antioxidant activities in the MTT and DPPH assays, respectively. The structure of compound 1 was determined by means of spectroscopic methods including 1D and 2D NMR experiments as well as HR-EIMS spectrometry. The stereochemical assignment of compound 1 was done based on the NMR results and X-ray crystallographic analysis. The preliminary assay results revealed that all the test compounds displayed potent inhibitory activity against HeLa cancer cell line, in particular with compound 1 which exhibited the highest cytotoxic activity comparable to the positive control used, cisplatin. However, no significant antioxidant activity was observed for all the test compounds in the DPPH radical scavenging capacity assay.

Keywords::

• chromanone acid
• caloteysmannic acid
• Calophyllum teysmannii
• cytotoxic
• NMR spectroscopy
• X-ray crystallography

Acknowledgements

This work was financially supported by the UTAR Research Fund (Project No. IPSR/RMC/UTARRF/2013-C2/L09). The authors also thank Mr. Tinjan Anak Kuda for authentication of the plant material.

Notes

^1. Present address: Center for Natural Products and Drug Research, University of Malaya, 50603 Kulala Lumpur, Malaysia.