Chemical composition of essential oil of Nepeta nuda L. 1753 (Syn. Nepeta pannonica L. 1753) from the Pannonian plain

Nepeta species are widely used in folk medicine because of their antispasmodic, expectorant, diuretic, antiseptic, antitussive, antiasthmatic and febrifuge activities. Most oils of Nepeta species contain nepetalactones as the main components. N. nuda is a rare plant species in the flora of the Pannonian part of Serbia and it has not been fully phytochemically evaluated yet. Thus, the aim of this study was to investigate the content and composition of volatile constituents of this wild growing species.

GC-MS analysis was performed with a Finnigan GCQ ion trap bench-top mass spectrometer. Identification of the compounds was based on comparisons with published MS data and a computer library search and also by comparison of their Kovats indices with those of authentic references and with literature values.

Essential oil content in dry herba of N. nuda was 0.2%. It has been detected 29 components, among them 22 identified. Sample contained predominantly sesquiterpenes (74.42%), where germacrene D (32.50%), β-caryophyllene (14.98%) and germacrene D-4-ol + spathulenol (4.80%) were major compounds. The content of monoterpenes was 7.40% with 1,8-cineol as the most abundant compound (5.05%).

Although the presence of nepetalactones in several Nepeta species in relatively high concentrations has been reported, no nepetalactones were found in this oil specimen. The predominance of germacrene D, β-caryophyllene and spathulenol has been found in essential oils of several Nepeta nuda ssp. from Turkey and Iran [1]. These compounds are typical in most Nepeta species.

References: 1. Kökdil, G. et al. (1998) Flavour Fragr J 13:233–234.