The components and anticancer activity of the volatile oil from Steblus asper
The volatile oil from fresh leaves of Streblus asper Lour. was isolated by hydrodistillation and analysed through a combination of gas chromatography with FID (GC–FID) and gas chromatography–mass spectrometry (GC–MS). The essential oil was obtained in 0.005% yield as a brown liquid. The major constituents of the volatile oil of S. asper were phytol (45.1%), α-farnesene (6.4%), trans-farnesyl acetate (5.8%), caryophyllene (4.9%) and trans-trans-α-farnesene (2.0%). In addition, the volatile oil showed signiﬁcant anticancer activity (ED50 << 30 µg/ml) from cytotoxicity primary screening tests with P388 (mouse lymphocytic leukaemia) cells but no signiﬁcant antioxidant activity (IC50 values of >>100 µg/ml) in a DPPH radical scavenging assay.