Chemical Constituents and Biological Activities of Commersonia bartramia Stems.

Commersonia bartramia (Sterculiaceae family) is a wooden tree, widely occurring in Australia, China and South East Asia. The MeOH extract of C. bartramia has been reported to show anticancer and antioxidant activities. Phytochemical investigation of C. bartramia stems led to the isolation of eight compounds. Their chemical structures were identified as helichrysoside-3'-methyl ether (1), tiliroside (2), pinoresinol (3), ursolic acid (4), quercetin (5), kaempferol (6), vanillic acid (7) and 4-hydroxybenzoic acid (8) using NMR and MS spectral analysis. This is the first study about the chemical composition of C. bartramia. Among the isolated compounds, quercetin (5) showed good DPPH's radical scavenging activity with IC₅₀ values of 11.43 ± 0.95 μg/mL, whereas the MeOH extract, (+)-pinoresinol (3) and kaempferol (6) displayed moderate activity. Quercetin (5) also displayed moderate cytotoxicity with IC₅₀ values of 43.64 ± 3.63 to 61.58 ± 5.54 μg/mL. The MeOH extract exhibited weak cytotoxicity against HepG2, MCF7 and A549 cell lines. [ABSTRACT FROM AUTHOR]