Nguyen Ngoc Tuan

Chemical constituents of essential oils from the leaves and stem barks of four Vietnamese species of Fissistigma (Annonaceae)

Chemical profiles of essential oils from four Fissistigma species: Fissistigma bracteolatum Chatt., Fissistigma villosissimum Merr., Fissistigma latifolium (Dunal) Merr. and Fissistigma glaucescens (Hance) Merr. were analysed by gas chromatography–flame ionisation detector and gas chromatography–mass spectrometry. Fissistigma essential oils consist mainly of sesquiterpenes (48.7–83.8%), monoterpenes (3.2–30.9%) and fatty acids (0.5–33.4%). Data on the essential oil composition of F. villosissimum, F. latifolium and F. glaucescens are reported for the first time.

Constituents of Essential Oils from the Leaves and Stem Barks of Uvaria rufa and Uvaria cordata (Annonaceae) from Vietnam

Abstract: Uvaria is a genus of flowering plants in the family, Annonaceae. The present study aimed to determine the chemical composition of essential oils hydrodistilled from the leaves and stem barks of Uvaria rufa Blume and Uvaria cordata (Dun.) Wall. ex Alston., grown in Vietnam. The oils were analysed by means of Gas chromatography-flame ionisation detector (GC-FID) and Gas chromatography-coupled with Mass spectrometry (GC-MS). We have found both quantitative and qualitative differences between the two samples. The main constituents of the leaf oil of U. rufa were δ-3-carene (12.8 %), n-hexadecanoic acid (9.1 %), β- caryophyllene (5.9 %), (Z)-β-ocimene (5.7 %) and γ-terpinene (5.4 %), while the stem oil was dominated by germacrene D (38.4 %), benzyl benzoate (18.1 %) and n-eicosane (5.5 %). In U. cordata oils, the major compounds were n-heneicosane (10.3 %), aristolone (9.8 %), bicycloelemene (6.5 %) and 2,4-bis(1,1- dimethylethl)-phenol (6.2 %) in the leaf; as well as n-eicosane (14.8 %), n-heneicosane (9.3 %), 2,6-di-t-butyl- 4-methylene-2,5-cyclohexadiene-1-one (6.7 %) and β-caryophyllene (6.6 %) in the stem.

Chemical Constituents from the Fruiting Bodies of Hexagonia apiaria and Their Anti-inflammatory Activity

A chemical investigation of the fruiting bodies of Hexagonia apiaria resulted in the identification of nine compounds including five new triterpenoids, hexagonins A-E (1-5), along with four known compounds. The purified constituents were examined for their anti-inflammatory activity. Among the tested compounds, hexatenuin A displayed the most significant inhibition of superoxide anion generation and elastase release. These triterpenoids may have potentials as anti-inflammatory agents.

A new benzofuran derivative from the leaves of Ficus pumila L.

Abstract A new benzofuran derivative, pumiloside (1), together with seven known flavonoid glycosides, afzelin (2), astragalin (3), quercitrin (4), isoquercitrin (5), kaempferol 3-O-rutinoside (6), rutin (7) and kaempferol 3-O-sophoroside (8) were isolated from the leaves of Ficus pumila. Their structures were established by spectroscopic data and comparison with the literature values.

Kadsura oblongifolia Merr. leaves, stem bark and root bark essential oils

Essential oils of Kadsura oblongifolia Merr. (Schisandraceae) were analyzed by capillary gas chromatography (GC) and GC coupled with mass spectrometry (GC–MS). Sixty, sixty-four and twenty-four compounds representing 99.4%, 90.5% and 99.8% of the total oil contents were identified, respectively, from the leaf, stem and root oil. Leaf oil contained cis-cadina-1,4-diene (22.6%), α-pinene (6.7%), α-amorphene (5.6%), cadina-4,10(15)-dien-3-one (5.2%) and δ-cadinene (5.2%), while the stem bark contained α-coapene (20.3%), α-pinene (9.3%) and 1,8-cineole (7.3%). The main constituents of the root were β-caryophyllene (24.9%), α-humulene (12.1%), β-selinene (8.5%) and α-amorphene (8.0%).

Chemical constituents from the fruiting bodies of Phellinus igniarius

Abstract A new tirucallane-type triterpenoid igniarine (1), and four known compounds meshimakobnol A (2), meshimakobnol B (3), ergosterol (4) and ergosterol peroxide (5), were purified from the methanol extracts of the fruiting bodies of Phellinus igniarius (DC. ex Fr.) Quél. The structure of 1 was elucidated using a combination of 1D and 2D NMR techniques and HR-ESI-MS analyses. In addition, the isolated compounds were examined for their cytotoxicity against several tumour cell lines and part of the tested compounds demonstrated weak cytotoxicity.

New cerebroside and chondrocyte proliferation activity of Caryota mitis L.

Abstract Caryota mitis L., a flowering plant, belongs to the family Arecaceae. In Vietnam, its fruits were used to treat joint pain. The present study was designed to investigate the phytochemicals and chondrocyte proliferation activity of C. mitis L. fruits on young human chondrocyte. The results showed that all of extracts (crude extract as well as n-hexane, chloroform, ethyl acetate and methanol fractions) were stimulated the growth of chondrocyte at 0.1 μg/mL; 0.01 μg/mL concentrations, of which the n-hexane and methanol fractions significantly increased the proliferation of chondrocyte by 30.75 and 24.42% at concentrations of 0.01 μg/mL, respectively. Repeated chromatography of the methanol fraction on silica gel, Sephadex LH-20 and ODS columns afforded a new cerebroside and eight known ones. Their structures were elucidated by analysis of spectral data and in comparison with the published reports.

Analysis of the Leaf Essential Oils of Uvaria grandiflora Roxb. ex Hornem. and Uvaria microcarpa Champ. ex Benth. (Annonaceae) from Vietnam

Abstract The chemical constituents of essential oils hydrodistilled from the leaves of Uvaria grandiflora Roxb. ex Hornem. and Uvaria microcarpa Champ. ex Benth. grown in Vietnam were identified by the techniques of gas chromatography-flame ionisation detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 29 and 13 compounds, representing 96.5 % and 99.9 % of the total oil contents were identified respectively in U. grandifolia and U. microcarpa. The main classes of compounds identified in U. grandiflora were monoterpene hydrocarbons (43.3 %), oxygenated monoterpenes (13.6 %), sesquiterpene hydrocarbons (13.7 %) and benezenoid compounds (17.3 %). However, phenylpropanids (50.8 %) and benzenoid compounds were the main classes of compounds present in U. microcarpa. The main compounds identified in U. grandiflora were limonene (25.2 %), benzyl benzoate (16.0 %), α-phellandrene (10.2 %), eugenol (7.3 %) and 1,8-cineole (6.1 %). However, eugenol (50.8 %) and benzyl benzoate (34.8 %) were the two major compounds identified in the leaf oil of U. microcarpa.