C. Menut

Quantification of 2-acetyl-1-pyrroline in rice by stable isotope dilution assay through headspace solid-phase microextraction coupled to gas chromatography–tandem mass spectrometry

A new and convenient synthesis of 2-acetyl-1-pyrroline (2AP), a potent flavor compound in rice, and its ring-deuterated analog, 2-acetyl-1-d(2)-pyrroline (2AP-d(2)), was reported. A stable isotope dilution assay (SIDA), involving headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-positive chemical ionization-ion trap-tandem mass spectrometry (GC-PCI-IT-MS-MS), was developed for 2AP quantification. A divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was used for HS-SPME procedure and parameters affecting analytes recovery, such as extraction time and temperature, pH and salt, were studied. The repeatability of the method (n=10) expressed as relative standard deviation (RSD) was 11.6%. A good linearity was observed from 5.9 to 779 ng of 2AP (r(2)=0.9989). Limits of detection (LOD) and quantification (LOQ) for 2AP were 0.1 and 0.4 ng g(-1) of rice, respectively. The recovery of spiked 2AP from rice matrix was almost complete. The developed method was applied to the quantification of 2AP in aerial parts and grains of scented and non-scented rice cultivars.

The Essential Oil of Xylopia parviflora (A. Rich) Benth. from Cameroon

ABSTRACT Twenty-eight compounds have been identified in the essential oil of fruits of Xylopia parviflora. The major components were β-pinene (40.0%), α-pinene (14.0%), trans-ocimene (5.4%) and camphene (4.0%).

Aromatic Plants of French Polynesia. V. Chemical Composition of Essential Oils of Leaves of Psidium guajava L. and Psidium cattleyanum Sabine

Abstract The leaf oils of Psidium guajava and Psidium catlleyanum collected in French Polynesia have been examined for the first time in Tahiti by GC and combined GC/MS. The leaf oil of P. guajava contained a mixture of sesquiterpene hydrocarbons (54.9%) and oxygenated sesquiterpenes (20.9%) with β-caryophyllene (18.3%) as the principal sesquiterpene hydrocarbon and selin-11-en-4a-ol (6.9%), α-cadinol (3.6%), (E)-nerolidol (3.2%) as the main oxygenated sesquiterpenes. Psidium cattleyanum produced oil that was much richer in sesquiterpene hydrocarbons (48.8%) and monoterpene hydrocarbons (10.1%). The main sesquiterpenes present in the oil were β-caryophyllene (31.5%) and α-humulene (4.4%). The two oils also contained a small amount of aromatic compounds, benzaldehyde (2.4%) in P. guajava oil, and the two isomers (E)-methyl isoeugenol (0.6%) and (Z)-methyl-isoeugenol (0.1%) in P. cattleyanum oil.

Aromatic Plants of French Polynesia. IV. Composition and Chemical Variations of the Essential Oils of Leaves of Etlingera cevuga (Seeman) R.E. Smith

Abstract The chemical variation of the essential oils of leaves of Etlingera cevuga collected in three locations of the island of Tahiti were studied by capillary gas chromatography and combined GC/MS. The chemical profile of the oils remains relatively constant where methyl eugenol (40.9–45.7%), (E)-methyl isoeugenol (8.6–16.5%), (Z)-methyl isoeugenol (0.8–1.5%) and eugenol (3.6–8.4%) accounted together for more than 55% of the oil.

Chemical Composition of Essential Oils From Bark and Leaves of Individual Trees of Ravensara aromatica Sonnerat

Abstract The chemical composition of essential oils obtained by hydrodistillation of leaves and bark (taken individually, tree by tree) of Ravensara aromatica Sonnerat of Madagascar was investigated by gas chromatography and gas chromatography coupled with mass spectrometry. Results were treated by principal component analysis. Four chemotypes highlighted about leaves in an earlier work were confirmed: chemotype 1 (> 90% methyl chavicol), chemotype 2 (72–80% methyl eugenol), chemotype 3 (25–28% α-terpinene) and chemotype 4 (25–34% sabinene). The chemical composition of R. aromatica bark is in all cases characterized by a high amount of methyl chavicol (83–98%), whatever the chemotype. One can conclude that the bark oil of R. aromatica corresponds to the oil described previously under the name “oil of R anisata.”

Aromatic Plants of French Polynesia. III. Constituents of the Essential Oil of Leaves of Ocimum basilicum L.

Abstract Sweet basil (Ocimum basilicum L.), one of the most popular aromatic plants, shows great variation in both morphology and essential oil components. In this study, the essential oils obtained by hydrodistillation from the leaves of three samples of basil of French Polynesia were investigated for the first time. The main constituents of the oil were (E)-methyl cinnamate (43.4–62.3%) and (Z)-methyl cinnamate (8.1–8.6%).

Essential oil Analysis and Antifungal Activity of three Satureja Species from Cameroon Against Aspergillus niger

Abstract Hydrodistilled essential oils from the herbal parts of Satureja pseudosimensis Brenan, Satureja punctata (Benth.) Briq and Satureja robusta (Hook. F.) Brenan. collected in Bamenda were analyzed by GC and GC-MS. Sabinene (13.2 %) was the main constituent in the oil of S. pseudosimensis in which thirty-six compounds were identified representing 99.5 % of the total composition. Nineteen compounds were characterized in the oil of S. punctata representing 99.9 % of the oil, with linalool (47.8 %), α-terpineol (16.2 %) and germacrene D (12.0 %) as the main constituents. In the oil of S. robusta, twenty compounds were identified representing 99.8 % of the total volume. Menthone (38.0 %), geraniol (11.1 %), thymol (14.1 %) and germacrene D (13.4 %) were the highest constituents. The essential oils of S. punctata and S. robusta were studied as potential antifungal agents for a phytopathogenic fungus. In a serial agar dilution method, both samples exhibited a very interesting antifungal profile after they were tested against Aspergillus niger and compared with Amphotericin B, a synthetic fungicide used as standard drug. This pathogen is very contagious and results in severe crop loss.

Optimization of antifungal activity of Aeollanthus heliotropioides oliv essential oil and Time Kill Kinetic Assay

OBJECTIVEnThe limitations encountered in the management of fungal infections are due to the resistance, high toxicity, and overuse of conventional antifungal drugs. For bringing solutions, the antifungal activity of Aeollanthus heliotropioides essential oil will be evaluated and optimized.nnnMATERIAL AND METHODSnThe aerial parts of A.xa0heliotropioides were harvested and essential oil extracted by hydrodistillation. The chemical composition was determined using gas chromatography and gas chromatography coupled with mass spectrometry and nuclear magnetic resonance. The sensitivity of fungal strains was determined using broth microdilution method. The fungicidal parameters were checked by viability assay using methylene blue dye. The Fractional Inhibitory Concentration Index was determined according the two-dimensional checkboard methods. The efficiency of the simulated optimum concentrations confirmed experimentally on American type culture collection strains, through the Time Kill Kinetic Study.nnnRESULTSnThe yield of extraction of essential oil was 0.1%. The major compounds were linalool (38.5%), Z-α-farnesene (25.1%), 9-hexa-decen-1-ol (13.9%) saturated/unsaturated massoia and γ-lactones (4.5%). The MIC of extract on yeast isolates ranged from 0.6mg/mL to 5mg/mL. The combination of essential oil with thymol leads mainly to synergistic effects (0.5≤FICI). The optimums of essential oil (1.6±0.4μl/mL) and thymol (0.6±0.1mg/mL) revealed a total inhibition of yeast after 120 and 180minutes according to the yeasts strains used.nnnCONCLUSIONnThis study highlights the in vitro antifungal activity of A.xa0heliotropioides essential oil and it synergistic effect with thymol.