Essential Oil of Ground Ivy (Glechoma hederacea L) Growing Wild In Eastern Lithuania, The

Abstract

The essential oil of overground parts of wild Glechoma hederacea L. collected at full flowering in seven localities of Eastern Lithuania were analyzed by GC and GC/MS. More than half of the oils were rich in sesquiterpene hydrocarbons (56.5-67.9%). The most predominant compound was germacrene D (14.1-20.7%). The other main constituents were γ-elemene (9.0-16.0%), β-elemene (8.7-12.9%), phytols (2.8-15.6%), (Z)-β-ocimene (2.2-8.5%), 1,8-cineole (92.2-5.4%), β-ylangene (2.7-4.1%) and germacrene B (2.2-3.9%). Forty-three identified compounds made up 89.1-96.2%.

Key Word Index

Glechoma hederacea, Labiatae, essential oil composition, germacrene D, γ-elemene, β-elemene, phytol.

Introduction

The overground parts of Glechoma hederacea L. colcted during flowering are used for healing different diseases and as a spice (1-5). Some authors regarded ground ivy as upper respiratory anticatarrhal herb (1,3,4). The herbs under study also help to heal diseases of digestion organs and skin (1,3). The leaves of G. hederacea are used for preparation salads, soups and drinks (1,3,5). The ground ivy in Lithuania has a strong odor. Two species of Glechoma L., i.e. G. hederacea and G. hirsuta, grow wdd (6). The first species is widespread and used for healing and spicing, the second one is rare and was found only in one district.

A review of the chemical composition of Labiatae oils included data on the od G. hederacea growing in North America in New Brunswick (7). The oil yield in the plants was

The present study deals with the composition of Glechoma hederacea oils from plants collected in seven localities in Eastern Lidiuania.

Experimental

Plant material: Samples of Glechoma hederacea were collected at full flowering in seven localities in Vilnius district (Lithuania) at 2005: A - Salininkai, B - Zolyno, C - Mistunai, D - Antakalnis, E - Nemencine, F - Seskine, G - Zujunai. The voucher specimens have been deposited in Herbarium of Institute of Botany (BILAS), Vilnius Lidiuania (numbers: A-268766, B-268767. C-268769, D-268771, E-268770, F- 268764, G-268768). The plant samples dried at room temperature (~20°C) were used for analysis. The oils were prepared by hydrodistillation for 3 h using a mixture of hexane and ethyl edier (1:1) for coUection of volatile compounds. The yield of the oils was ~0.02-0.03%.

Analysis of the oils and identification of the components: GC/MS analyses were perform ed using a Chromatograph interfaced with an HP 5971 mass spectrometer

(ionization voltage 70 eV) and equipped with a CP-Sil 8 CB capdlary column (50 m × 0.32 mm. film thickness 0.25 µm).The oven temperature was held at 60°C for 2 min then programmed from 60°-160°C at a rate of 5°C/min, held for 1 min and then programmed to 250°C at the rate of 10°C/min held for 5 min, using He as a carrier gas (1,0 mL/min). The injector and detector temperatures were 200° and 250°C, respectively.

GC analysis was performed with a HP 5890II Chromatograph with a FID and a capdlary column HP-FFAP (30 m ? 0.25 mm. Film thickness 0.3 µm was used for quantitative analysis. The GC oven temperature was set at 70°C for 10 min and then programmed from 70°-210°C at a rate of 3°C min using He as carrier gas (0.7 mL/min). The injector and detector temperatures were 200° and 2500C, respectively.

The percentage composition of the oils was computed from GC peak areas without correction factors. Qualitative analysis was based on the comparison of retention times and the mass spectra widi corresponding data in the e literature and the computer mass spectra libraries (Wiley and NBS 54K).

Results and Discussion

Ground ivy overground plants collected in seven localities included only 0.02-0.03% of the oils, but they have a strong odor. Germacrene D (14.1-20.7%) dominated in all above oils (Table I). The close amount (19.4%) of it was found in the earlier investigated oil from America (7). The constituents widi germacrene carbon skeleton (germacrene D + germacrene B + germacrene D-4-ol) comprised 18.8-25.4% of the G. hederacea oils (Table I). The second and the third positions were occupied by γ- (9.0-16.0%) and β-elemenes(9.7-12.9%)in five oils (A, D-G). The oils B and C in the second position included γ-elemene (10.8-16.0%), in the third phytols (9.8-15.6%) and in the fourth β-elemene (8.7-9.8%). The compounds with elemane carbon skeleton (β-, γ- and δ-elemenes) made up 20.9-28.6% of the oils. Four oils (A, D-G) might be attributed to germacrene / elemene chemotype and three samples (A-C) containing marked amounts of phytols beside above compounds were of germacrene/elemene/phytols chemotype. The part of elemenes according to literature data (8) might be sometimes produced from germacrenes during GC analysis. The sum of compounds with germacrane and elemane carbon skeletons was more stable characteristic of the oils. The amount of the compounds with bodi carbon skeletons varried from 40.3-47.8% in five oils (C-G) but in two samples (A, B) exceeded the half of the oils (52.9-53.2 %). The three oils A, B and D containing 47.8 -53.2% of compounds with germacrane and elemane carbon skeletons included the largest amounts of sesquiterpene hydrocarbons (63.3-67.9%) and sesquiterpenoids (67.9-71.5%). The other samples C, E, F and G contained 56.5-56.9% of the above hydrocarbons and 59.2-60.1% of sesquiterpenoids.