Composition of the essential oil of Ballota undulata, B. nigra ssp. foetida and B. saxatilis

The essential oil composition of Ballota nigra ssp. foetida, B. undulata and B. saxatilis, collected during the flowering phase in Amman (Jordan), Naur (Jordan) and Pisa (Italy) respectively, was investigated. The chemical composition of the essential oil of B. nigra and B. undulata shows some similarities: monoterpenes are little represented, while sesquiterpenes are present in large amounts. In both cases germacrene D is the main compound. B. saxatilis essential oil is quite different from B. nigra and B. undulata ones: sesquiterpenes are still the main class of compounds but monoterpenes are much more represented; moreover, in this case the main compound is the oxygenated monoterpene, linalool