Chemical Variability of the Essential Oil Isolated from Aerial Parts of Tetraclinis articulata from North-Western Algeria.

The objective was to investigate the yield and chemical composition of 50 essential oil samples isolated from leaves and flowers of Tetraclinis articulata harvested in eight locations (coastal township and highlands) of Tlemcen Province (North-Western Algeria). Essential oil yields varied drastically from sample to sample (0.03 to 0.86%, w/w). No direct correlation was observed between the yield and the altitude of the harvest areas. The oils consisted mainly of monoterpenes: α-pinene (9.2-56.5%), bornyl acetate (1.2-45.1%), camphor (0.5-40.3%), borneol (0.2-12.9%), limonene (3.6-12.5%), and myrcene (1.6-9.7%). Sesquiterpenes were represented by germacrene D (up to 14.2%) and (E)-ß-caryophyllene (up to 13.3%). PCA analysis of the data allowed the distinction of two groups within the samples. The composition of group I (9 samples) was dominated by camphor, (Mean = 30.9%) followed by α-pinene (M = 19.1%) and bornyl acetate (M = 11.4%). Group II was divided into two sub-groups. Samples of sub-group IIA (8 samples) contained mainly α-pinene (M = 45.4%). Samples of the largest group IIB (33 samples) were characterized by similar contents of α-pinene (M = 28.2%) and bornyl acetate (M = 24.5%) and the occurrence of camphor to a lesser extent (M = 10.0%).

Potential assessment of Rumex vesicarius L. as a source of natural antioxidants and bioactive compounds.

The present work is designed to evaluate the antioxidant activities of hydroalcoholic extract (HAE) and its fractions (viz., hexane (HF), chloroform (CF), ethyl acetate (AF), n-butanol (BF) and water (WF)) obtained from aerial part of Rumex vesicarius L. by using different in vitro antioxidant assays. The content in pigments (carotenoids and chlorophylls), total phenolics, flavonoids and tannins were determined using spectrophotometric methods. Qualitative analyses of major phenolics by TLC analysis were also evaluated. Experimental results obtained show that R. vesicarius is a rich source of ß-carotene (116.83 ± 1.60 µg/g DW), lycopene (156.40 ± 1.59 µg/g DW) and chlorophyll a (271.45 ± 3.46 µg/g DW). The greatest antioxidant activity was found in AF (IC50.DPPH = 0.07 ± 0.00 mg/ml) followed by BF and CF (0.15 ± 0.00 and 0.16 ± 0.00 mg/ml, respectively). These fractions were also better in their effect on reducing the oxidation of ß-carotene. Reducing power of crude methanol extract/fractions increased with increasing concentration of the extract. The amount of total phenolics varied from 0.37 ± 0.01 to 43.28 ± 0.28 mg GAE/g of dry weight, HAE had the higher content (43.28 ± 0.28 mg GAE/g of DW). A negative correlation was found between phenolic compounds and the antioxidant efficiencies of the crude extract/fractions, suggesting that phenolic compounds are not the only contributors to the antioxidant activities of Rumex vesicarius. The present findings suggest that Rumex vesicarius L. can be used as natural antioxidant source to prevent damage associated with free radicals.

Antimicrobial activity and evolution of the composition of essential oil from Algerian Anacyclus pyrethrum L. through the vegetative cycle.

Essential oils from the aerial parts of Anacyclus pyrethrum L. were analysed at three developmental stages (vegetative, floral budding and flowering). Oil yield was found to vary depending on the stage of development, and the highest content of oil (0.019% w/w) was obtained at flowering stage. The chemical composition of essential oils studied by GC and GC-MS showed a total of 91 compounds. Whatever the analysed stage is, oxygenated sesquiterpenes were the most abundant group. Their level significantly increased during ripening and varied from 37.1% to 58.6%. The oil showed activity against Candida albicans and Staphylococcus aureus bacteria strains. Thus, they represent an inexpensive source of natural antibacterial substances that may potentially be used in pathogenic systems.