Essential Oil Composition of an Endemic Species of Turkey: Marrubium bourgaei Boiss. ssp. bourgaei (Labiatae)

Journal of Essential Oil Research: JEOR, Jan/Feb 2007 by Kürkçüoglu, Mine, Baser, K Hüsnü Can, Tosun, Alev, Dogan, Ebru, Duman, Hayri

Abstract

Water-distilled essential oil from the aerial parts of Marrubium bourgaei Boiss. ssp. bourgaei (Labiatae, Lamiaceae) from Turkey was analyzed by GC and GC/MS. Seventy-eight components were characterized in total, representing 90.7% of the oil. Hexadecanoic acid (33.3%) and hexahydrofarnesyl acetone (6.4%) were main constituents.

Key Word Index

Marrubium bourgaei ssp. bourgaei, Labiatae, essential oil composition, hexadecanoic acid, hexahydrofarnesyl acetone.

Plant Name

Marrubium bourgaei Boiss. ssp. bourgaei (1).

Source

Aerial parts of Marrubium bourgaei Boiss. ssp. bourgaei were collected from Antalya-Bakirlar Mountain, rocky slopes, in August 2002, at an altitude of 2300-2500 m. The species was identified by one of us (HD). A voucher specimen has been deposited at the Herbarium of the Faculty of Pharmacy of Ankara University (AEF 22914).

Plant Part

Powdered aerial parts of Marrubium bourgaei Boiss. ssp. bourgaei were subjected to water distillation for 3 h using a Clevenger-type apparatus. The yield of oil was 0.4% (v/w) on dry weight basis.

Previous Work

The family Labiatae (Lamiaceae) consists of herbs and shrubs, usually glandular and aromatic. The family is composed of many culinary or flavoring herbs, native to Turkey and the Mediterranean area. While the family is represented by 45 genera, the genus Marrubium L. comprises 22 species as annual and perennial herbs in Turkey. One of them, Marrubium bourgaei Boiss. ssp. bourgaei, is described as an endemic species in the Flora of Turkey (1).

Diterpene compounds, flavonoids, phenylethanoid and phenylpropanoid components were isolated from Marrubium species (2-5). Furthermore, anti-inflammatory and antioxidant activities of the extracts and compounds of Marrubium species have been investigated (5-7). The leaf oil composition of M. vulgare was examined and the main components were reported to be (Z)-β-farnesene (9.6%), β-caryophyllene (8.5%), (E)-2-hexenal (4.7%) and germacrene D (4.7%) (6). In Turkish folk medicine, flowering stems of M. vulgare are used as diuretic, anti-flatulence and expectorant (8). γ-Muurolene (27.8%), β-caryophyllene (24.3%) and caryophyllene oxide (6.0%) were characterized as principal components of the oil from aerial parts of M. velutinum Sm. The oils of two populations of M. peregrinum L. contained (Z)- and (E)-β-farnesene as main constituents (9). In another study, bicyclogermacrene (37.9%) and germacrene D (24.1 % ) were identified as major components from the oil of aerial parts of M. cuneatum Russell (10). In the oil of M. bourgaei ssp. caricum, β-caryophyllene (23.2%), (Z)-β-farnesene (13.5%), carvacrol (12.5%) andgermacrene D (10.3%) were found as the main constituents (11). Hexadecanoic acid (15.4%), germacrene D (11.1%), β-caryophyllene (10.0%) and (E)-β-farnesene (7.3%) were characterized as main constituents in the oil of M. parviflorum Fisch. et Mey. ssp. oligodon (Boiss.) Seybold (12).

Present Work

The oil was analyzed by GC and GC/MS systems. GC analysis was carried out using a Hewlett-Packard HP 6890 GC system. Innowax FSC column (60 m x 0.25 mm) was used with N^sub 2^ as carrier gas. Oven temperature was kept at 60°C for 10 inin and increased up to 220°C at a rate of 4°C/min, and then kept constant at 220°C for 10 min and increased up to 240°C at a rate of l°C/min. Split ratio was adjusted to 50:1. The injector and FID detector temperatures were 250°C.

GC/MS analysis was conducted using a Hewlett-Packard GC/MSD system. The same column and operational conditions as in GC were applied. Carrier gas was He. MS were taken at 70 eV. Mass range was between m/z 35 to 425. Library search was carried out using the in-house Baser Library of Essential oil Constituents. Relative percentage amounts of the separated compounds were calculated from FID chromatograms. Alkanes were used as reference points in the calculation of relative retention indices (RRI).

The compounds characterized in the oil can be seen in Table I. Hexadecanoic acid (33.3%) was found as main component in M. bourgaei ssp. bourgaei. To the best of our knowledge, this is the first chemical study on M. bourgaei Boiss. ssp. bourgaei.

References

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2. N.A.R. Hatam, A. Porzel and K. Seifert, Polypodonne, aprefuraniclabdane dfterpene from Marrubium polypodon. Phytochemistry, 40, 1575-1576 (1995).

3. G. Savona, F. Piozzi, LM. Aránguez and B. Rodriguez, Diterpenas from Marrubium supinum anofMarrubium alysson. Phytochemistry, 18,859-860 (1979).

4. A. Karioti, H. Skaltsa, J. Hellmann and O. Sticher, Acylated flavonoid and phenylethanoid glycosides from Marrubium velutinum. Phytochemistry, 64, 655-660 (2003).

5. S.Sahpaz,N.Garbackl,M.TItsandF.Bailleul,/so/af/onanc/priarmaco/og/ca/ activity of phenylpropanold esters from Marrubium vulgare. J. Ethnopharmacol., 79, 389-392 (2002).

6. K.G.C. Weel, PR. Venskutonis, A. Pukalskas, O. Gruzdiene and J.P.H. Linssen, Antioxidant activity of horehound (Marrubium vulgare L.) grown in Lithuania. Fett/Lipid, 10, 395-400 (1999).