Chemical composition and antibacterial activity of Ruta graveolens L. (Rutaceae) volatile oils, from São Luís, Maranhão, Brazil

• Seven compounds representing 100% of the oil were identified
• The main compounds were 2-nonanone (39.17%) and 2-undecanone (47.21%)
• Antibacterial activity against Gram-positive and Gram-negative bacteria
• Zone of inhibition 8.30 ~ 25.60 mm and MIC values of 0.75 ~ 1.40 μg mL− 1
• Bacillus cereus and Staphylococcus aureus most susceptible

This study investigated the chemical composition and antibacterial activities of volatile oil isolated from the fresh leaves of Ruta graveolens L., Rutaceae, from São Luís, Maranhão, Brazil. The essential oil was isolated using hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC–MS. Seven compounds representing 100% of the oil were identified. The main compounds were 2-nonanone (39.17%) and 2-undecanone (47.21%). Antibacterial activity against Gram-positive and Gram-negative bacteria with inhibition zones of 8.30–25.60 mm to MIC values of 0.75–1.40 μg·mL− 1, the most susceptible bacterium was Bacillus cereus and Staphylococcus aureus. It is concluded from the present study that besides its traditional use, Ruta graveolens L. could be used as a natural source for antibacterial compounds and possible applications in the pharmaceutical industry.