Essential oil composition and antimicrobial activity of Hyptis atrorubens Poit. from Martinique (FWI)

The volatile constituents obtained by hydrodistillation of the aerial parts of Hyptis atrorubens Poit. growing in Martinique (F.W.I.: French West Indies) were analyzed by a combination of GC/FID and GC-MS. Plants from two different locations in Martinique (North and South) were studied. For the north location, two preparation methods were studied: hydrodistillation in 3L or 20 L reactors and steam distillation. Sixty components representing between 87.7% and 93.2% of the essential oil GC/FID chromatogram total area were identified. The most abundant compounds were caryophyllene oxide (from 5.0 to 31.5%), -caryophyllene (from 4.7 to 32.6%), palmitic acid (from 2.0 to 9.5%), spathulenol (from 1.5 to 8.5%), -copaene (from 4.5 to 6.9%), 2-tridecanone (from 0.0 to 6.1%) and phytol (from 2.3 to 4.8%). By comparison with the literature describing a first chemotype rich in Germacrene D and a second chemotype rich in limonene and estragole, in our study Germacrene D was only present at 1.1 and 2.1% in the northern oil. Limonene was present in the oil from 0.1 to 0.3%. Furthermore, no estragole was found in this essential oil. Antimicrobial activity of the essential oil from aerial parts of the plant was also investigated. Antibacterial and antifungal activities were observed against A. niger, C. albicans, S. aureus, E. coli, and B. cereus at 0.5%.