Phenolic compounds from the bark of Aglaia lawii and their cytotoxic activity against HepG2

Abstract

Introduction: Aglaia lawii is a large tree belonging to the Meliaceae family. In traditional medicine, the stem bark is used as a vermicide while the leaves are used for the treatment of headache. Studies on the chemical constituents of this species in Vietnam and its biological activity, especially its ability to treat liver cancer, are still limited. This work describes the isolation and structure elucidation of six phenolic compounds from an ethyl acetate extract of the bark of A. lawii as well as the evaluation of cytotoxic activity against HepG2.

Methods: The extracts were prepared by extracting the dried ground bark using Soxhlet extraction. Isolation was performed using column chromatography over silica gel, RP-18 and using gel permeation chromatography over Sephadex LH-20. Chemical structures were elucidated using spectroscopic methods (1D- and 2D-NMR, HR-ESI-MS and IR) and comparison of spectral data with those in literature. Cytotoxic activity against HepG2 human liver cancer cells was evaluated in vitro using the MTT assay.

Results: Six phenolic compounds, palmarumycin JC2 (1), 5-hydroxy-4',7-dimethoxyflavone (2), coniferaldehyde (3), 3-hydoxy-1-(4¢-hydroxy-3¢-methoxyphenyl)propan-1-one (4), p-hydroxybenzaldehyde (5), and vanillin (6), were isolated from an ethyl acetate extract of the bark of A. lawii collected in Dong Nai Province. Compounds 1-3 were evaluated for their cytotoxicity against HepG2 cells and the result showed that the compounds exhibited weak effects or no activity.

Conclusion: All the isolated compounds have been reported from this species for the first time. It is also the first report on the cytotoxicity of 1-2 against HepG2 cells although the compounds displayed weak effects.

Keywords: Aglaia lawii; phenolic compounds, cytotoxicity, HepG2