CHEMICAL COMPOSITION OF ESSENTIAL VOLATILE OILS OF SELAGINELLA SPP. AND THEIR ANTIBACTERIAL ACTIVITY

The chemical composition of the volatile oils of three species of Selaginella viz. S. moellendorfii, S. helvetica and S. delicatula, was studied by gas chromatograph-mass spectrometer (GC-MS). The major chemical groups occurring in the essential oils were aliphatic hydrocarbon (19.43 - 42.8%), higher alcohols (4.57 - 11.9%), ketones (3.36 - 20.81%) and sesquiterpene (2.3 - 62.59%). The main constituents of the essential oils were phytone (1.8 - 20.33%), 2-pentylfuran (4.78 - 5.91%) and copaene (53.1%). The antibacterial activity of the volatile oils from three species of Selaginella plants was evaluated against three Gram-positive bacteria namely, Staphylococcus aureus, Diplococcus pneumoniae, Corynebacterium pyogenes and three Gram-negative bacteria namely, Escherichia colii, Pseudomonas aeruginosa, and Proteusbacillus vulgaris, by the agar disc diffusion method. The results of antibacterial test indicated that the volatile oils of three species of Selaginella showed good antibacterial activity, especially against Corynebacterium pyogenesi. Moreover, the essential oils of S. moellendorfii have the strongest antibacterial effect against Corynebacterium pyogenes (MIC and MBC were both 5 mg/mL). The results clearly demonstrated that the essential volatile oils of three Selaginella species can be used as a possible source for antibacterial drug development by the modem pharmaceutical industries.