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Essential oils isolated from leaves, twigs, fruit bark and seeds of Michelia tonkinensis collected in Muong Nhe Nature Reserve, Dien Bien province were obtained by hydrodistillation with yields of 1.5, 0.42, 0.16 and 4.6% respectively (v/w on dry weight basis). After analysis through GC, GC-MS and 13C NMR, 30, 34, 31 and 13 compounds (representing 96.4%, 96.8%, 97.1% and 99.9% of the whole composition, respectively) were identified in the leave, twig, fruit bark and seed essential oils. The main components were limonene (43.2%) and germacrene D (32.7%) in the leaf oil; limonene (67.1%) and germacrene D (10.4%) in the twig oil; limonene (66%) in the fruit bark oil; and safrole (90%) in the seed oil. Essential oils from the leaves and twigs showed strong inhibition against Staphyloccocus aureus. The fruit bark essential oil exhibited greater antibacterial potential against all 3 tested microorganisms (S. aureus, Escherichia coli and Candida albicans). The essential oil from seed displayed weak antibacterial activity against the three tested microorganisms. [ABSTRACT FROM AUTHOR]

The needle and cone essential oils of Pinus fenzeliana Hand-Mazz. (Pinus kwangtungensis Chun & Tsiang) collected in Hang Kia-Pa Co Nature Reserve, Hoa Binh province were obtained by hydrodistillation and analyzed by a combination of GC-FID, GC-MS and NMR (Gas Chromatography/Gas Chromatography-Mass Spectrometry/Nuclear Magnetic Resonance (NMR) analysis). The oil yields were 0.2% and 0.37% respectively (v/w on dry weight basis). Twenty-seven compounds were detected in both needle and cone oils, accounting for 98.0% and 98.2% of the whole composition, respectively. The main components identified in the needle oil were α-pinene (20.7%), β-pinene (11.3%), δ-3-carene (32.2%), limonene (8.0%) and E-β-caryophyllene (7.1%). The cone oil contained mainly α-pinene (19.3%), β-pinene (45.4%), δ-3-carene (3.5%), limonene (12.7%) and E-β-caryophyllene (3.4%). This is the first report on the chemical composition of the cone essential oil of P. fenzeliana from Vietnam. [ABSTRACT FROM AUTHOR]

Essential oils produced from a population of Artemisia vulgaris of Vietnamese origin cultivated near Hanoi were subjected to analysis by GC, GC/MS and 13C-NMR. The oils were found to contain oxygenated monoterpenes as major components (1,8-cineole, camphor and a-terpineol). The composition of these oils differed from that previously reported for Vietnamese A. vulgaris oil. Only slight differences in the composition of the oil were observed along the vegetative life of the plant. No significant difference was observed between compositions of leaf and flower oils. In addition, the combination of retention indices, GC/MS and 13C-NMR spectroscopy allowed the identification of unusual sesquiterpenes such as presilphiperfolan-9α-ol as a minor component. [ABSTRACT FROM AUTHOR]

The chemical composition of Litsea cubeba essential oils obtained from leaves harvested in six provinces of Vietnam were investigated using a combination of capillary GC, GC/MS and 13C-NMR spectroscopy. Three compositions were found, dominated by 1,8-cineole (0.2-51.7%), linalool (0.4-91.1%) and sabinene (0-48.1%). [ABSTRACT FROM AUTHOR]

The chemical composition of essential oils from several parts of a type of Illicium griffithii (short peduncle) harvested in Vietnam was investigated using GC, GC/MS and 13C-NMR spectroscopy. These oils contained mostly oxygenated phenylpropanoids, essentially safrole (51.6-65.3%) and 4-methoxysafrole (19.6%, root bark oil). Oils from aerial parts and bark of root oil differed significantly. [ABSTRACT FROM AUTHOR]

The essential oil isolated from Asarum cordifolium C. E. C. Fischer recently discovered in Vietnam, and A. glabrum Merr., an endangered species listed as vulnerable in the Red Data Book of Vietnam, have been analyzed by a combination of chromatographic and spectroscopic techniques including 13C NMR spectroscopy. The composition of A. cordifolium essential oil, investigated for the first time, was dominated by elemicin (82.5%). The essential oil isolated from A. glabrum contained safrole (41.9%) as its major component and was characterized by the diversity of phenylpropanoids contained in this oil (10 compounds).