Changes in content and chemical composition of Dracocephalum moldavica L. essential oil at different harvest dates

Dracocephalum moldavica L. (Lamiaceae = Labiatae) is one of the most important medicinal plants has powerful biological activity and pharmacological properties. The chemical constituents of essential oil by hydro distillation from the aerial parts of Dracocephalum moldavica L. from Egypt were identified by gas chromatograph-mass spectrometer (GC-MS) demonstrated the presence of 33 compounds. The volatile oil content has been analyzed by GC/MS. The GC/MS revealed the presence of geranyl acetate [(28.81, 27.02 and 27.81%); geranial (citral a) (20.42, 19.37 and 19.74%); neral (citral b) (18.36, 17.85 and 17.86%) and geraniol (12.66, 16.05 and 16.68%) which represents the main compounds of volatile oil extracted from Dracocephalum moldavica fresh herb. However, geranyl acetate compound contents were the highest in the volatile oil, followed by geranial, then neral and finally geraniol in all harvest dates.