Chemical composition and antibacterial activity of the essential oil of Hyptis leucocephala

The paper reports chemical composition and antimicrobial activity of the essential oil of Hyptis leucocephala Mart ex Benth, Lamiaceae, isolated by hydrodistillation from leaves of plants collected in Casa Nova, semi-arid region of Northeastern Brazil. A total of ten compounds were identified, of which carvacrol as the main component (average 52.82%). This essential oil was also characterized by high level of biogenetic precursor of the phenols: p-cimene (18.13%) and y-terpinene (10.72%), and by E-cariophyllene, were the most abundant sesquiterpene hydrocarbons. Bioassay revealed a significant antibacterial activity of the essential oil against Pseudomonas aeruginosa, Staphylococcus schleiferi, S. aureus, Salmonella typhi, E. coli, Bacillus pumillus, Burkholderia cepacia, Klebsiella pneumoniae with varying magnitudes. The minimal inhibition concentrations values extended from 50 to 250 µg mL-1. The essential oil showed high antioxidant activity. The free radical scavenging capacity of the oil was determined with an EC50 value of 3.41 mg mL-1. The data herein obtained show the relevant potential of H. leucocephala as a source of potent bioactivity compounds