JEOR: Chemical Composition of the Sawdust Oil of Moroccan Tetraclinis articulata Vahl

Chemical Composition of the Sawdust Oil of Moroccan Tetraclinis articulata Vahl

Zrira, Saadia

Abstract

The essential oil, which was obtained by hydrodistillation from the sawdust of Tetraclinis articulata Vahl from Morocco, was analyzed by a combination of GC and GC/MS. Twenty-five components were identified among which carvacrol (21.3-36.4%), α-cedrene (10.1-13.1%), cedrol (1-7.3 %) and terpinen-4-ol (2.8-6%) were the main compounds.

Key Word Index

Tetraclinis articulata, Cupressaceae, essential oil composition, carvacrol, α-cedrene.

Plant

Tetraclinis articulata Vahl. The plant material was collected in Morocco from Khemisset (80 km north of Rabat) and Aoulouz (600 km south of Rabat). One hundred g of wood sawdust was hydrodistilled in a Clevenger-type apparatus for 3 h to produce an oil in 3.75% yield for Aoulouz region and 1.9% for Khemisset.

Previous Work

Tetraclinis articulata Vahl is an endemic species of North Africa, Malta and Spain. This species is an important source of biomass in dry lands. In Morocco, T. articulata populations cover about 60,700 hectares representing 6.74% of the total forest plantations and it generally occurs mixed with Pinus halepensis (1). Not many authors have studied the chemical composition of T. articulata sawdust oil (2).

Present Work

The essential oils were analyzed by a combination of GC and GC/MS.

GC: The GC analysis was carried out using an HP 5980 gas chromatography apparatus equipped with FID and a DB-5 capillary column (25 m × 0.25 mm, film thickness 0.25 µm). Analytical conditions were: injector and detector temperature 240°C and 260°C, respectively; oven temperature programmed from 50°-250°C at 4°C/min and then 250°C for 10 min using a carrier gas 1 mL N2/min. Relative concentrations were calculated using peak areas as given by HP 3396A integrator, without correction for response factors. Retention indexes were obtained by injection of the homologous hydrocarbons series C^sub 8^-C^sub 30^ in the same conditions (programmed temperature).

GC/MS: The analysis was performed on a Hewlett Packard 5980 GC Series II gas Chromatograph equipped with HP-5 capillary column (25 m × 0.3 mm, film thickness 0.25 µm) and an HP 5772 mass selective detector. Analytical conditions were: injector and detector temperature 240°C and 260°C, respectively; oven temperature programmed from 50°-250°C at 4°C/min, then 250°C for 10 min using a carrier gas 2 mL He/min; source 70 eV.

The oil constituents were identified by the combination of retention indices data and mass spectra data using NBS library and other literature data (3,4). Twenty-five compounds representing over 70% of the oil were identified (Table I). The major components were carvacrol (21.3-36.4%), oc-cedrene (10.1-13.1%), cedrol (1-7.3 %) and terpinen-4-ol (2.8-6%). An unidentified sesquiterpene was also present in relatively high proportions.

The comparison of our results with those previously reported for the wood oil of T. articulata from other locations in Morocco (2) showed that both oils contained carvacrol and α-cedrol but our oil was characterized by the absence of thymohydroquinone, p-methoxythymol and the presence of heptanol, γ-himachalene, β-sesquiphellandrene and tetradecane.

References

1. M. Fenane, Phytosociology of Tetraclinis articulate formations in Morocco. Bulletin de l’Institut Scientifique, 12, 99-148 (1988).

2. M.A. Igri, M. Holeman, A. Ilidrissi and M. Berrada, Contribution to the chemical study of essential oils from the twigs and wood of Tetraclinis arliculata (Vahl) Masters. Plant. Med Phytother., 24, 36-43 (1990).

3. Laseve, Mass Spectra and Retention Indices Data Base. Université de Québec à Chicoutoumi (UQAC), Canada (1996).

4. R.P.Adams, Identification of Essentialoils by Ion Trap Mass Spectroscopy. Academic Press, Inc., San Diego (1989).

Saadia Zrira* and Bachir Benjilali

Département des Sciences Alimentaires et Nutritionnelles Institut Agronomique et Vétérinaire Hassan II, B. P. 6202, Rabat-Instituts, Morocco

Abdelaziz Elamrani

Département de Chimie, Université Hassan II Ain Chock, faculte des sciences Ain Chock, B. P. 5366, Maarif, Casablanca, Morocco

* Address for correspondence

Received: August 2001

Revised: April 2002

Accepted: July 2002

Copyright Allured Publishing Corporation Jan/Feb 2005

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