Aoumeur Baaliouamer

GC and GC/MS leaf oil analysis of four Algerian Cypress species

Abstract The leaf oils of four Cypress species growing in Algeria were examined by GC and GC/MS. In total 76 constituents were identified, from which 49, 46, 48 and 54 compounds were found in the oils of Cupressus glabra Sudw., C. arizonica Greene, C. sempervirens L. and C. dupreziana Camus. The main components of the oils were: C. glabra: terpinen-4-ol (10.5%) and umbellulone (27.4%); C. arizonica: α-pinene (10.5%) and umbellulone (37.3%); C. sempervirens: α-pinene (2.8–44.9%), δ-3-carene (31-10.6%) and α-terpinyl acetate (5.5–12.0%) and C. dupreziana: α-pinene (36.4%) and δ-3-carene (33.8%).

Tetraclinis articulata (Vahl) Masters essential oils: chemical composition and biological activities

Two samples of essential oils from the leaves and cones of wild Tetraclinis articulata (Vahl.) Masters from two different sites in Algeria were isolated by hydrodistillation and investigated by gas chromatography (GC) and GC/mass spectrometry (GC/MS). A total of forty compounds were identified representing 98.6–99.8% of the oils. The main components of the volatile oils were α-pinene (19.8–24.9%) and bornyl acetate (40.2–59.2%) for the leaves, α-pinene (57.5–75%), limonene (10.6–20.9%) and β-myrcene (3.6–10.6%) for the cones. The antioxidant efficiency was tested using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging method. In comparison with butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA), which were used as positive controls, all samples showed weak activity. The antimicrobial activities of the essential oils were assayed by using the disc diffusion method and agar dilution technique on Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923. All tested microorganisms were inhibited by essential oil samples and the minimum inhibitory concentration (MIC) values ranged between 0.2 and 1.0 μg/mL.

The chemical composition of some cold-pressed citrus oils produced in Algeria

ABSTRACT The cold-pressed oils of five orange cultivars, a Tangor hybrid and the Clementine Tangerine, which were obtained from fruit grown in Algeria, were examined by GC/MS. The orange oils were found to contain the following number of constituents: Washington-Navel (43), Portuguese (61), Valencia (43), Hamlin (24) and Sanguine (23). The Tangor hybrid oil was found to contain 34 components, while 25 components were found in the Clementine oil. The use of preparative GC as a method to remove the monoterpene hydrocarbons prior to GC/MS analysis was demonstrated.

Analysis and Antioxidant Activity of the Essential Oils of Ferula vesceritensis Coss. et Dur. and Thymus munbyanus Desf

Abstract The essential oils from leaves of Thymus munbyanus Desf. and Ferula vesceritensis Coss et Dur. were analyzed by GC and GC-MS and assayed for their antioxidant activities. Eighty nine components representing 93 - 96.8 % of the oils were characterized. Sesquiterpene hydrocarbons (37.0 %) and oxygen-containing sesquiterpenes (47.8 %) were the predominant classes in the oil of F. vescertentis with viridiflorol (13.4 %), δ-cadinene (10.1 %) and famesol (8.1 %) as major constituents; while oxygen-containing monoterpenes (66.4 %) was the most prominent group in T. munbyanus oil with carvacrol (35.2 %) and thymol (18.5 %) as the main constituents. The antioxidant activities of the essential oils were evaluated by DPPH free radical-scavenging and thiobarbituric acid reactive substances (TBARS) assays. For both tests, T. munbyanus oil showed potent activity, similar to that of BHT, mainly for high concentrations, whereas F. vesceritensis oil showed moderate activity.

Chemical composition and insecticidal properties of Lantana camara L. leaf essential oils from Algeria

Essential oils extracted from Lantana camara were tested for fumigant activity against Sitophilus granarius adults. Composition of L. camara essential oil included large amounts of sesquiterpene hydrocarbons, mainly β-caryophyllene. The bioactivity of the essential oil extracted by hydrodistillation from leaves of L. camara was assessed under laboratory conditions. With fumigation bioassays, essential oils showed different activities on S. granarius. April essential oil, after 24 hours of exposure, exerted the highest activity. Similar results were obtained for February and June essential oils after 48 hours of exposure, although December essential oil showed good fumigant activity after 96 hours of exposure. The persistence of the insecticidal efficiency of the essential oil (remanence tests) against S. granarius adults confirmed that June essential oil was efficient for 2 weeks. Even if laboratory bioassays are only the first step towards the use of essential oils in practical applications, these substances represent a possible alternative to chemical insecticides in some market places.

Composition of the Essential Oils of the Leaves and Flowers of Thymus pallescens de Noé and Origanum floribundum Munby From Algeria

Abstract The essential oils of Thymus pallescens de Noé and Origanum floribundum Munby leaves and flowers were analyzed by GC and GC/MS. The oil yields of T. pallescens were 2.8% for the leaves and 3.7% for the flowers, while those of O. floribundum were 2.0% for the leaves and 5.4% for the inflorescences. The major constituents of both the leaves and flowers of T. pallescens were p-cymene (17.4% and 9.2%), γ-terpinene (10.6% and 14.1%) and carvacrol (39.0% and 48.3%), respectively, while those of O. floribundum were p-cymene (22.3% and 9.6%), γ-terpinene (17.3% and 24.3%) and thymol (34.4% and 41.2%), respectively. For the both plants p-cymene and sesquiterpenes were essentially concentrated in leaves.

Analysis of Algerian essential oils from twigs, needles and wood of Cedrus atlantica G. Manetti by GC/MS

Abstract The variation and composition of essential oils from needles, twigs and wood of Cedrus atlantica G.Manetti (Atlas cedar), grown in Algeria were investigated. The compounds of the oils were identified using GC and GC/MS. The major components isolated from the oils were found to be α-pinene (5.6–23.4%), camphene (0.4–1.8%), myrcene (0.1–2.7%), α- terpineol (0.8–6.7%), β-caryophyllene (6.0–11.4%), α-humulene (1.3–2.3%) and caryophyllene oxide (trace-10.3%). Quantitative and qualitative differences in the oil components were found between oils produced in the summer.

Biological Activities of Essential Oils and Ethanol Extracts of Teucrium polium subsp. capitatum (L.) Briq. and Origanum floribundum Munby

Abstract The present study was conducted to evaluate the in vitro antioxidant, anti-inflammatory and antimicrobial activities of the essential oils and crude ethanol extracts of Teucrium polium subsp. capitatum Briq. and Origanum floribundum Munby from Algeria. A total of 78 and 55 constituents were identified, representing 92 and 98.4 % of the total chemical composition of Teucrium and Origanum essential oils, respectively. Monoterpenes (22 %), sesquiterpenes (31.2 %) and oxygenated sesquiterpenes (25.5 %) dominated in the oil of T. polium with t-cadinol (18.3 %), germacrene D (15.3 %) and β-pinene (10.5 %) as predominant compounds; while monoterpenes (51.3 %) and oxygenated monoterpenes (45.2 %) were the most prominent groups in O. floribundum oil characterized by thymol (33.6 %), γ-terpinene (19.9 %) and p-cymene (15.5 %). The ethanol extracts were analyzed in terms of the dosage in total phenolic and flavonoids contents. Gallic acid equivalent representing total phenolic constituents of the extracts of T. polium and O. floribundum were 175 and 250 mg GAE/g, respectively; and quercetin equivalent representing total flavonoids were 29.5 and 180 mg QE/g, respectively. The antioxidant potential of the samples was evaluated using two separate methods, inhibition of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power. O. floribundum extract was the most able to reduce DPPH (IC 50= 18.5±0.1 µg/ml). Both plant oils were able to inhibit the 5-lipoxygenase (IC50= 125.7±7.3 µg/ml for Origanum and 482.52±0.73 µg/ml for T. polium. The antimicrobial activity of the oils and Origanum extract by the disc diffusion method against four bacteria and one fungus showed O.floribundum as being more active.

Chemical Composition and Antioxidant Activity of Algerian Juniperus phoenicea L. Extracts

Essential oils of Algerian Juniperus phoenicea L. obtained from leaves and berries by hydrodistillation (HD) and from berries by Solvent Free Microwave Assisted Extraction (SFMAE) were investigated using both capillary GC and GC-MS techniques. The monoterpene hydrocarbons constituted the most prominent group of constituents (43.2-86.5 %) in the three essential oils with α-pinene (34.4-80.8 %) as the main compound. Leaves ethanol extract was analyzed in terms of the dosage in total phenolic and flavonoids contents. Gallic acid equivalent representing total phenolic constituents of the extract was 308 mg GAE/g; and quercetin equivalent representing total flavonoids was 20 mg QE/g. The antioxidant potential of the samples was evaluated using two separate methods, inhibition of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power. All essential oils showed a relatively weak antioxidant capacity. No improvement of the antioxidant activity by SFMAE technique has been detected. J. phoenicea ethanol extract was found to be remarkably effective toward DPPH inhibition, compared to chemical antioxidant BHT (IC = 9.8±0.1 and 28±0.7 mg/l, respectively); for reducing power test it has also exhibited high activity in comparison with all studied essential oils and the chemical standard (BHT).

Larvicidal activity of two Algerian Verbenaceae essential oils against Culex pipiens.

The purpose of this study was to evaluate the bioactivity of essential oils extracted from the leaves of Verbena officinalis and Lantana camara L. for the control of Culex pipiens. Triplicate bioassays were performed with fourth larval instars of C. pipiens (n=25 per replicate) with solutions at 1, 5, 10, 50, 100 and 500 μL/L of V. officinalis and L. camara L. extracts. Cumulative mortalities were determined 3, 6, 12 and 24h after treatment. Results showed cumulative mortalities, at three (3) hours to be 30.0 ± 2.9% and 14.8 ± 1.5% and achieve 43.3 ± 1.9% and 44.4 ± 3.1% after 24h exposure time, at 100mg/L of essential oil from L. camara and V. officinalis, respectively.