Sideritis romana L. subsp. purpurea (Tal. ex Benth.) Heywood, a new chemotype from Montenegro
A study on essential oil fractions of the Western Balkan endemic Sideritis romana L. subsp. purpurea (Tal. ex Benth.) Heywood collected in Montenegro is reported. The 24-h systematic steam distillation extraction procedure was performed. The gas chromatographic/mass spectrometric (GC/MS) analysis of the fractions showed ?-elemene and spathulenol as two main constituents, revealing a new chemotype of this plant species.