Extracts obtained from three Malaysian Labiatae plants, including Ocimum sanctum, Mentha
arvensis and Orthoshiophon staminea, were investigated for their biological activity. The volatile fraction
of each plant was isolated and the major components were characterized by gas chromatography (GC),
gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR). The antibacterial
and antifungal activity, insecticidal activity and inhibition of the germination of seeds of the
volatile fraction and residue were studied