Screening of the odour-activity and bioactivity of the essential oils of leaves and flowers of Hyptis Passerina Mart. from the Brazilian Cerrado

The chemical profile of the essential oils obtained from the leaves and flowers of Hyptis passerina Mart., a rare species of the Brazilian Cerrado, has been determined for the first time. Analyses by GC-MS showed sesquiterpenes as major compounds. beta-epi-acorenol (35.7% and 32.8%, respectively from leaf and flower essential oils), was isolated and identified by 1D and 2D NMR. The flower-derived oil presented a higher concentration of hydrocarbon and oxygenated monoterpenes, while the leaf-oil was richer in diterpenes. The global odour impressions of both oils were given by direct analysis and GC-MS-O and were characterized as herbaceous with tea notes, and green, cooked and woody impressions for leaf-oil; herbaceous, with spicy, woody and minty notes for flower-oil. beta-epi-acorenol, spathulenol, beta-caryophyllene, and caryophyllene oxide were relevant for the odour-activity of both oils, as well as minor constituents, such as linalool. The antimicrobial activity was investigated by means of agar diffusion disc method and contact bioautography, against Gram-positive and negative bacteria and yeast. Both oils presented to be bioactive against the tested microorganisms with significant inhibition level.