Essential Oil Composition of Different Aerial Parts of Pistacia terebinthus L. Growing Wild in Sardinia

Journal of Essential Oil Research: JEOR, Jul/Aug 2006 by Usai, Marianna, Pintore, Giorgio, Chessa, Mario, Tirillini, Bruno

Abstract

Essentials oils from different aerial parts of Pistacia terebinthus L. growing wild in Sardinia were analyzed in a single GC and GC/MS run. The oil yields obtained from the different parts range from 0.01-1.5%. α-Pinene was the main constituent of each of the P. terehinthus oils with the twig oil containing the highest concentration of 66.0%. In fruitful twigs the α-pinene concentration was 54.8% while in the leaf oil it was 16.4%. The other major component was β-pinene, the level of which in the oils of fruitful twigs and leaves was 22.5% and 13.5%, respectively.

Key Word Index

Pistacia terebinthus, Anacardiaceae, essential oil composition, α- pinene, β-pinene.

Introduction

Pistacia terebinthus L. (Anacardiaceae) is a small deciduous tree or shrub up to 5 in that is widely distributed in the Middle East and Southern Europe and prefers dry, open woods and rocky, usually calcareous slopes (1). In Sardinia, this species is present only in a calcareous restricted area of east coast. Pwtacia species have a wide range of uses in traditional medicine and some demonstrated activities. Resin is used in alcoholic and non-alcoholic refreshments in some cosmetic mixtures, as ingredient of filling material in dentistry; against some stomach disease and antiseptic for respiratory system (2). The extracts are also used in eczema treatment, as anti-inflammatory and antibacterial (3-4).

Pistacia species have been the subject of numerous investigations in which different classes of constituents such as flavonoids, triterpenoids, phenolics and essential oils have been studied (5-11). The studies on P. terebinthus are more limited (12-19) and in particular very few have been made on P. terebinthus oil (4,11,20-21). The aim of this paper was to determine and compare the composition of oil from different aerial parts of P. terehinthus growing in Sardinia (Italy).

Experimental

Pistacia terhinthus plant material was collected in a middleeast station of Sardinia (Calagonone) in May 2003 during fructification. A. Atzei identified the analyzed plant material. Voucher specimens have been deposited at the Herbarium SASSA of the Dipartimento di Scienze del Farmaco, University of Sassari under collective number n° 279. Leaves, twigs and fruitful twigs were considered for analysis.

Oil distillation and yield: The fresh plant material (leaves, twigs and fruitful twigs) were separately hydrodistilled using a Clevenger-type apparatus (22) for 4 h. The oils were dried over anhydrous sodium sulfate and stored at -20°C until they were analyzed.

GC analyses: Four replicates of each sample were analyzed by using a Varian 3300 instrument equipped with a FID and an HP-InnoWax capillary column (30m x 0.25 mm, film thickness 0.17 µm), working from 60°C (3 min) to 210°C (15 min) at 4°C/min or an HP-5 capillary column (30 m x 0.25 mm, film thickness 0.25 µm) working from 60°C (3 min) to 300°C (15 min) at 4°C/min; injector and detector temperatures, 250°C; carrier gas, helium (1 mL/min); split ratio, 1:10.

GC/MS: Analyses were carried out using a Hewlett Packard 5890 GC/MS system operating in the EI mode at 70 eV, using the two above mentioned columns. The operating conditions were analogous to those reported in the GC analyses section. Injector and transfer line temperatures were 220°C and 280°C, respectively. Helium was used as the carrier gas, flow rate 1 mL/min. Split ratio, 1:10.

The identification of the components was made for both columns by comparison of their retention time with respect to n-alkanes (C6-C22). The mass spectra and retention indices (RI) were compared with those of commercial (NIST 98 and WILEY) and home-made library mass spectra built up from pure compounds and MS literature data (23-28). The percentage composition of oil was obtained by the normalization method from the GC peak areas, without using correction factors.

Results and Discussion

The hydrodistillation of the leaves (L), twigs (T) and fruitful twigs (FT) gave yellowish oils with ayield of 0.01%, 0.05%, and 1.5%, respectively. Sixty-two compounds were identified in the L oil, representing 98.9% of the total oil, 19 compounds were identified in the T oil, representing 99.2% of the total oil and 30 compounds were identified in the FT oil the representing 99.4% of the total oil. The composition of the oils is given in Table I; the compounds are listed in order of their elution from an HP-5 column.

The major compounds in the oil from L were Ot-pinene (16.4%) and β-pinene (13.5%). The major compounds in the oil from T were α-pinene (66.0%) and α-terpineol (9.0%). The major compounds in the oil from FT were α-pinene (54.8%) and β-pinene (22.2%).

In the oil from L, the monoterpene hydrocarbons represented 43.6% of the total oil, α-pinene (16.4%) being the major compound. The oxygenated monoterpene fraction was relatively abundant, representing 28.7% of the total oil with CC-pinene oxide (2.7%) being the major constituent of this fraction. The sesquiterpene hydrocarbons, oxygenated sesquiterpenes and ester fraction constituted 13.2%, 4.7% and 3.6%, respectively.