Activity against Streptococcus pneumoniae of the Essential Oil and δ-Cadinene Isolated from Schinus molle Fruit

Streptococcus pneumoniae is a major cause of respiratory infections. This study aims to test the activity of the essential oil obtained from the fruit of Schinus molle against S. pneumoniae resistant to conventional antibiotics and to identify the compounds responsible for the activity. A fraction showing antimicrobial activity (MIC 125 mu g/mL) was obtained. The principal components were identified as: beta-myrcene (39.7%), p-cymene (19.5%), delta-cadinene (7.8%), alpha-phellandrene (7.1%) and limonene (4.1%). Bioassay-guided fractionation led to the identification of delta-cadinene as the principal active constituent (MIC of 31.25 mu g/mL). The findings reported here highlight and justify the global spread of the use of S. molle for the treatment of respiratory infections.