The chemical composition and antibacterial activity of the leaf extract of Salvia repens Burch. Ex Benth

Abstract

The chemical composition of the essential oil of S. repens contain the following major constituents: 1 – camphor (0.4%) para–cymene (34.1%), sabinene (23.9%), 1–b–pinene (16.9%),, myrcene (3.9%), γ -terpinene (1.8%), trans- b–Ocimene (1.3%), terpinene-4-ol (0.7%), nopol (0.4%), a-terpinolene (15.89%), b - caryophllene (0.6%). The antibacterial activity of the aerial parts of Salvia repenshas shown that the acetone extract inhibited the growth of Bacillus cereus,Streptococcus pyrogens and Escherichia coli bacteria tested at minimum inhibitory concentration (MIC) of 0, 5 mg/ml. The methanol extracts effectively inhibited the growth of both Staphylococcus epidermidus and Micrococcus kristinae at minimum concentration of 0, 5 mg/ml. At 0. 1 mg/ml the methanol extract inhibited the following B. cereus, S. pyrogens and E. coli bacteria whose inhibition concentration was below 0. 5 mg/l. The activity of the water extracts of the plants against Gram-negative and Gram-positive bacteria has shown inhibition at 1.0 and 2.5 mg/l respectively. The extract from the methanol also suggest that, the plant extract has intensive activity at low concentration compare to acetone and water. The antibacterial activity suggests a possibility of S. repens plant for use on medicinal applications Key words: Salvia repens, essential oil composition, antibacterial medicinal plant, para–cymene, sabinene, 1–b–pinene, a-terpinolene.