Bioactive lignans from the seeds of Centaurea macrocephala

The essential oil from flowering aerial parts of Nepeta depauperata Benth., an endemic Iranian plant, obtained by steam distillation was analyzed by GC/MS. The constituents were identified by their mass spectra and Kovats’ indices. Thirty-three compounds consisting 82.52% of the total components were identified from the oil obtained with a yield of 0.3%v/w. Among them, spathulenol (31.84%), beta caryophyllene (12.93%) and caryophyllene oxide (10.27%) were the major components of the oil.