Chemical Constituents of the Essential Oil of Nepeta oxyodonta

GC and GC-MS analysis of the essential oil of Nepeta cilicica Boiss. ex Benth. from Lebanon

The hydrodistillation of the aerial parts of Nepeta cilicica Boiss. ex Benth., collected in Lebanon in the Horsh Ehden reserve, yielded 0.13% (w/w) of essential oil. Gas chromatography (GC) and GC-mass spectroscopy analysis enabled the identification of 75 compounds representing 96.8% of the total oil. The most abundant compounds were spathulenol (15.1%), hexadecanoic acid (14%), δ-cadinene (5.5%) and α-copaene (4.5%). On the whole, the oil was constituted mainly by sesquiterpenes (45.9%), among which sesquiterpene hydrocarbons (27.6%) slightly prevailed over oxygenated sesquiterpenes (18.3%).

Essential Oil Composition of Two Subspecies of Nepeta Glomerulosa Boiss. from Iran

Essential oil compositions of Nepeta glomerulosa Boiss. subsp. glomerulosa and N. glomerulosa subsp. stapfiana (Bornm. ex Rech. f.) Rech. f., each gathered from two different locations, have been investigated by GC and GC/MS. 1,8-Cineole was the major compound in the oils of both collections of subspecies glomerulosa (27.4%, 30.6%), and was also a major constituent of subspecies stapfiana (14.9%, 17.8%). However, caryophyllene oxide was the predominant compound for both oils of subspecies stapfiana (32.0%, 24.1%). From the chemotaxonomic point of view, the two members of each subspecies comprised a separate group with a considerable distance from the other two, and the morphological differences of these two subspecies were well reflected in their essential oil compositions.