The chemical constituents and the cytotoxicity, antioxidant and antibacterial activities of the essential oil of Graptophyllum pictum (L.) Griff

The essential oil from the leaves of Graptophyllum pictum (L.) Griff. was isolated by hydrodistillation and its chemical constituents were investigated by a combination of gas chromatographic (GC-FID) and gas chromatography-mass spectrometric (GC-MS) analysis. Fourteen compounds, comprising 95.0 % of the gas chromatographical oil, were identified. The major constituents were phytol (75.7 %), n-nonacosane (6.5 %) and hexahydrofarnesyl acetone (2.6 %). The oil showed significant cytotoxicity against KB (epidermoid carcinoma of oral cavity), NCI-H187 (small cell lung carcinoma) and Vero cell lines with IC50 values of 27.04, 25.27 and 26.52 µg/mL, respectively. The antioxidant activity of the oil was determined using the ABTS radical cation scavenging assay. The oil had less antioxidant activity than the controls, trolox and ascorbic acid. In a disc diffusion assay the oil exhibited antibacterial activity against S. aureus and E. coli with MIC values of 11.75 and 35.25 µg/disc, respectively.