Chemical Composition, Antioxidant and Antibacterial Activities of Essential Oil From Cymbopogon densiflorus (Steud.) Stapf Flowers

This study reports, for the first time, the chemical composition and biological activity of essential oil from Brazilian Cymbopogon densiflorus flowers. Thirty chemical compounds were identified by gas chromatography coupled with mass spectrometry (GC/MS), corresponding to 95 % of total compounds from an essential oil chromatogram obtained by gas chromatography-flame ionization detection (GC-FID ). The essential oil was mainly composed of cis-p-mentha-1(7),8-dien-2-ol (26 %), trans-p-mentha-1(7),8-dien-2-ol (18 %), trans-p-mentha-2,8-dien-1-ol (13 %) limonene (9 %), cis-p-mentha-2,8-dien-1-ol (7 %), cis-carveol (7 %) and carvone (5 %). The identity confirmation of the major compounds was performed by 1H/13C heteronuclear single-quantum coherence nuclear magnetic resonance (HSQC NMR). The essential oil exhibited a weak antioxidant activity by the DPPH method and a wide spectrum of antimicrobial activity against the pathogenic bacterial strains tested, showing some efficacy against 7 of the 10 strains with the greatest inhibition observed with the Gram-negative bacterium Shigella sonnei.