Tran Huy Thai

Artemisia vulgaris L. from Vietnam: Chemical Variability and Composition of the Oil Along the Vegetative Life of the Plant

Abstract 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 α-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.

Chemical composition of patchouli oil from Vietnam

The essential oil of Pogostemon cablin (Blanco) Benth. grown in Vietnam, was analyzed by capillary gas chromatography and mass spectrometry. Patchouli alcohol accounted for about 32–38% of the patchouli oil. Ten more compounds were identified, of which α-bulnesene and α-guaiene were the main components.

Composition and antimicrobial activity of the essential oil of Acronychia pedunculata (L.) Miq. from Vietnam

The chemical composition and the antimicrobial activity of the essential oil isolated from aerial parts of Acronychia pedunculata (L.) Miq. from Vietnam are reported. Analysis was carried out by GC (RI), GC–MS and 13C NMR. Thirty-four compounds were identified, accounting for 92.8% of the oil. The major constituents were α-pinene (57.4%) and (E)-β-caryophyllene (13.6%). The essential oil of A. pedunculata was shown to possess a broad spectrum of antimicrobial activity against various bacteria, particularly Salmonella enterica and Staphylococcus epidermidis.

The leaf essential oils of four Vietnamese species of Cinnamomum (Lauraceae)

The leaf essential oil compositions of four Cinnamomum species from Vietnam were analyzed by gas chromatography (GC) and GC–mass spectrometry (GC–MS). The main compounds of Cinnamomum sericans Hance were the sesquiterpenes spathulenol (14.5%), caryophyllene oxide (9.3%), β-caryophyllene (7.1%) and bicyclocgermacrene (6.0%). The monoterpenes were represented by α-pinene (9.3%) and sabinene (8.0%). However, monoterpenes were the dominant class of compounds in Cinnamomum durifolium Kosterm comprising mainly of ρ-cymene (15.6%), limonene (13.9%) and α-phellandrene (9.2%). Spathulenol (7.4%) among the sesquiterpenoids and benzyl benzoate (6.5%), an aromatic ester were also present. The leaf oil of Cinnamomum magnificum Kosterm was devoid of monoterpene compounds, while the major sesquiterpenes were bicyclogermacrene (33.9%), β-caryophyllene (25.5%), bicycloelemene (7.2%) and caryophyllene oxide (7.5%). β-Caryophyllene (35.9%), caryophyllene oxide (12.6%) and spathulenol (5.2%) were the dominant compounds of Cinnamomum iners Reinw. ex Blume. The low content of (E)-cinnamaldehyde in the Cinnamomum species is typical for majority of species already reported from Vietnam.

Chemical composition of leaf and stem oils from Vietnamese Cupressus tonkinensis Silba.

Cupressus tonkinensis was treated for a long time as a synonym of Cupressus torulosa D. Don. and it was proposed as new species in 1994. The two species differed by morphological characters and they were distinct in their random amplified polymorphic DNAs (RAPDs). Leaves and stems of C. tonkinensis produce monoterpene-rich oils whose composition is investigated here for the first time by combination of chromatographic and spectroscopic techniques. α-Pinene (23.1%), sabinene (21.0%) and terpinen-4-ol (14.4%) were the major components of the leaf oil that contained also β-elemol (4.2%). In contrast, α-pinene (42.5%) was by far the major component of the stem oil beside myrcene (10.2%) and cedrol (9.0%).

Integrated Analysis of the Wood Oil from Xanthocyparis vietnamensis Farjon & Hiep. by Chromatographic and Spectroscopic Techniques

In order to get better knowledge about the volatiles produced by Xanthocyparis vietnamensis, a species recently discovered in Vietnam, its wood oil has been analyzed by a combination of chromatographic (GC, CC) and spectroscopic (GC-MS, 13C-NMR) techniques. Forty components that accounted for 87.9% of the oil composition have been identified. The composition is dominated by nootkatene (20.7%), 11,12,13-tri-nor-eremophil-1(10)-en-7-one (17.2%), γ-eudesmol (5.1%), nootkatone (4.7%), valencene (3.5%) and 13-nor-eremophil-1(10)-en-11-one (2.6%). The structure of two new compounds—10-epi-nor-γ-eudesmen-11-one and 12-hydroxy-isodihydroagarofuran—has been elucidated, while 11,12,13-tri-nor-eremophil-1(10)-en-7-ol is reported as a natural product for the first time. The composition of X. vietnamensis wood oil varied drastically from those of leaf oils, dominated by hedycaryol (34.4%), phyllocladene (37.8%) or by pimara-6(14)-15-diene (19.4%).

The Chemical composition of leaf oil of Cupressus tonkinensis Silba. in Huu Lien, Lang Son province

Cupressus tonkinensis Silba. is an evergreen, medium-sized tree, up to 15-25 cm in height. Bark is gey brown with longitudinal fissures. Leaves are scaly, closely inserted on twigs. Cones are unisexual, grouped on a stalk. Male cone is subglobular. This is an endangered species in Vietnam, only found in a narrow area of the Central Region and the North belonging to Lang Son and Tuyen Quang provinces. This is a light-demanding species, thriving in hot and wet tropical and subtropical forests and occurring naturally as dominant stands at elevation of 800-1200 m. The yield of essential oil from the air-dried leaves was 0.13 percent. By using GC/MS analysis, 26 constituents have been identified. The main constituents of essential oil were sabinen (29.34%), a-pinen (25.4%), 4-terpineol (13.91%) and g-terpinen (5.5%).

Zingiber nitens M.F. Newman: A New Species and its Essential Oil Constituent

an (Zingiberaceae) growing in Vietnam was performed by means of gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) techniques. The yields of essential oils were 0.22%, 0.16% and 0.30% (v/w) respectively for leaf, stem and root, calculated on a dry weight basis. The main constituents of the leaf oil were δ-elemene (17.0%), β-pinene (12.8%) and β-elemene (8.8%). The stem oil comprised mainly of δ-elemene (20.1%), germacrene D (8.6%) and bicyclogermacrene (8.1%). The root oil had an abundance of β-pinene (21.0%), δ-elemene (12.8%) and bornyl acetate (11.8%). This is the first report on the volatile constituents of Z. nitens.

Chemical constituents of leaf essential oils of four Scrophulariaceae species grown in Vietnam

In the present investigation, the essential oil compositions of four individual plants from Scrophulariaceae family cultivated in Vietnam were reported. The air-dried plants were hydrodistilled (Vietnamese Pharmacopoeia) and the oils were analyzed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) techniques. The essential oils content varied between 0.15% and 0.40% (v/w) on a dry weight basis. Monoterpenes (74.0%–85.1) represent the main class of compound in the oils. Adenosma bracteosa Bon., afforded oil whose major compounds were carvacrol (37.2%), carvarol methyl ether (23.2%), α-bisabolene (15.9%) and γ-terpinene (9.2%). The oil of Adenosma indiana (Lour.) Merr., comprised mainly of limonene (25.1%), 1,8-cineole (20.1%) and α-pinene (17.2%). However, methyl benzoate (27.7%), pulegone (23.4%) and limonene (20.2%) were the significant compounds of Limnophila aromatica (Lour.) Merr., while Limnophila micrantha (Benth.) Benth., gave oil whose main compounds are mentha-1,5,8-triene (38.5%) and β-myrcene (24.4%).

Chemical composition of the essential oil of Xanthocyparis vietnamensis Farjon and Hiep from Vietnam

Chemical composition of the essential oil of Xanthocyparis vietnamensis Farjon and Hiep from Vietnam