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Tran T.T.,Vietnam Institute of Industrial Chemistry | Kim M.,Korea Research Institute of Chemical Technology | Jang Y.,Korea Research Institute of Chemical Technology | Lee H.W.,Korea Research Institute of Chemical Technology | And 5 more authors.
BMC Complementary and Alternative Medicine | Year: 2017

Background: Polygonum chinense Linn. is a common medicinal plant in Southeast Asia and has been used in traditional medicine in Vietnam. The plant contains phytochemicals with various biological properties; however, its antiviral effect has not yet been demonstrated. This study was aimed to evaluate the anti-influenza virus activity of crude extracts of P. chinense, to characterize antiviral metabolites therefrom and to investigate their mechanisms of antiviral action. Methods: The methanol (MeOH) extract and organic solvent layers of P. chinense were prepared by extraction and partition with relevant solvents. The ethyl acetate (EtOAc) layer showing antiviral activity was chromatographed repeatedly on SiO2 and Sephadex LH-20 columns to give eight pure metabolites. Their chemical structures were determined by NMR and MS spectral data. Anti-influenza virus activity of the eight metabolites against virus strains A/Puerto Rico/8/34 (H1N1, PR8), A/Hong Kong/8/68 (H3N2, HK) and B/Lee/40 (Lee) was evaluated on the basis of cytopathic effect (CPE) and plaque inhibition assays. Time-of-addition, confocal microscopy and neuraminidase inhibition assay were performed for mode-of-action studies of active ingredients. Results: The MeOH extract of P. chinense showed anti-influenza virus activity with EC50 values ranging from 38.4 to 55.5μg/mL in a CPE inhibition assay. Among the eight pure metabolites isolated from P. chinense, ellagic acid (PC5), methyl gallate (PC7) and caffeic acid (PC8) significantly inhibited viral replication in a dose-dependent manner in both plaque inhibition and CPE inhibition assays with EC50 values ranging from 14.7 to 81.1μg/mL and CC50 values higher than 300μg/mL. Mode-of-action studies suggested that PC5 and PC7 suppress virus entry into or replication in cells, while PC8 targets influenza viral neuraminidase, even oseltamivir-resistant one. Conclusion: These results demonstrated that P. chinense and its metabolites possess effective anti-influenza virus activities. The botanical materials of P. chinense could be a promising multitargeted inhibitor of influenza A and B viruses and applied to development of a novel herbal medicine. © 2017 The Author(s).


Le Dang Q.,Korea Research Institute of Chemical Technology | Le Dang Q.,Vietnam Institute of Industrial Chemistry | Shin T.S.,Dongbu Farm Hannong Company | Park M.S.,Korea Research Institute of Chemical Technology | And 5 more authors.
Journal of Agricultural and Food Chemistry | Year: 2014

The antagonistic fungus Simplicillium lamellicola BCP has been developed as a microbial biopesticide that effectively controls the development of various plant diseases caused by both pathogenic bacteria and pathogenic fungi. Antibacterial bioassay-directed fractionation was used to isolate mannosyl lipids from S. lamellicola BCP, and the structures of these compounds were elucidated using spectral analysis and chemical degradation. Three novel mannosyl lipids were characterized and identified as halymecins F and G and (3R,5R)-3-O-β-d-mannosyl-3,5-dihydrodecanoic acid. Massoia lactone and (3R, 5R)-3-hydroxydecan-5-olide were also isolated from S. lamellicola BCP. The three novel compounds inhibited the growth of the majority of phytopathogenic bacteria that were tested, and halymecin F displayed the strongest antibacterial activity. Agrobacterium tumefaciens was the most sensitive to the three novel compounds, with IC50 values ranging from 1.58 to 24.8 μg/mL. The ethyl acetate extract of the fermentation broth from the antagonistic fungus effectively reduced the bacterial wilt caused by Ralstonia solanacearum on tomato seedlings. These results indicate that S. lamellicola BCP suppresses the development of plant bacterial diseases through the production of antibacterial metabolites. © 2014 American Chemical Society.


Jang J.Y.,Chonnam National University | Jang J.Y.,Chungbuk National University | Le Dang Q.,Vietnam Institute of Industrial Chemistry | Choi Y.H.,Korea Research Institute of Chemical Technology | And 5 more authors.
Journal of Agricultural and Food Chemistry | Year: 2015

The methanol extract of the aerial part of Triumfetta grandidens (Tiliaceae) was highly active against Meloidogyne incognita, with second-stage juveniles (J2s) mortality of 100% at 500 μg/mL at 48 h post-exposure. Two 4-quinolone alkaloids, waltherione E (1), a new alkaloid, and waltherione A (2), were isolated and identified as nematicidal compounds through bioassay-guided fractionation and instrumental analysis. The nematicidal activities of the isolated compounds against M. incognita were evaluated on the basis of mortality and effect on egg hatching. Compounds 1 and 2 exhibited high mortalities against J2s of M. incognita, with EC50 values of 0.09 and 0.27 μg/mL at 48 h, respectively. Compounds 1 and 2 also exhibited a considerable inhibitory effect on egg hatching, which inhibited 91.9 and 87.4% of egg hatching, respectively, after 7 days of exposure at a concentration of 1.25 μg/mL. The biological activities of the two 4-quinolone alkaloids were comparable to those of abamectin. In addition, pot experiments using the crude extract of the aerial part of T. grandidens showed that it completely suppressed the formation of gall on roots of plants at a concentration of 1000 μg/mL. These results suggest that T. grandidens and its bioactive 4-quinolone alkaloids can be used as a potent botanical nematicide in organic agriculture. © 2014 American Chemical Society.


Vu T.H.T.,Vietnam Institute of Industrial Chemistry | Nguyen T.T.T.,Vietnam Institute of Industrial Chemistry | Nguyen P.H.T.,Vietnam Institute of Industrial Chemistry | Do M.H.,Vietnam Institute of Industrial Chemistry | And 4 more authors.
Materials Research Bulletin | Year: 2012

Composite of multi-walled carbon nanotubes (MWNTs) and titanium (IV) oxide (TiO 2) were prepared by a heterogeneous gelation method. The activities of the MWNTs/TiO 2 composites were evaluated by photocatalytic oxidative desulfurization using dibenzothiophene (DBT), 4,6-dimethyl dibenzothiophene (4,6-DMDBT), n-tetradecane, and commercial diesel under irradiation using a high-pressure Hg lamp. The microstructures of MWNTs/TiO 2 composites were characterized by N 2 adsorption, scanning electron microscopy, transmission electron microscope, and X-ray diffraction. It was found that more than 98% of sulfur compounds in commercial diesel were oxidized and removed by the use of the MWNTs/TiO 2 composite as a photocatalyst. © 2011 Elsevier Ltd. All rights reserved.


Dang Q.L.,Korea Research Institute of Chemical Technology | Dang Q.L.,Chungnam National University | Choi Y.H.,Korea Research Institute of Chemical Technology | Choi G.J.,Korea Research Institute of Chemical Technology | And 7 more authors.
Journal of Asia-Pacific Entomology | Year: 2010

The methanol extract of dried roots of Euphorbia kansui, known as "Gan Sui" in oriental medicine, showed pesticidal activity against brown plant hopper (Nilaparvata lugens Stal) and two-spotted spider mite (Tetranychus urticae Koch). Bioassay-guided fractionation led to the isolation of two active compounds from the dried roots of E. kansui. The substances were identified as 3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoylingenol (1) and 3-O-(2′E,4′Z-decadienoyl)-ingenol (2) by MS and NMR spectral data. Both compounds exhibited insecticidal activity against the brown plant hopper and compound 1 was active against the two-spotted spider mite. Compared to anise oil and eugenol, the two ingenane diterpenes showed greater activity against brown plant hopper. The results suggest that 3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoylingenol and 3-O-(2′E,4′Z-decadienoyl)-ingenol could be used directly as natural pesticides or as lead principles for the control of brown plant hopper and two-spotted spider mite. © 2009 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society.


Au H.T.,Hankyong National University | Pham L.N.,Hanoi University of Science | Vu T.H.T.,Vietnam Institute of Industrial Chemistry | Park J.S.,Hankyong National University
Macromolecular Research | Year: 2012

Nonwoven mats made of a poly(lactic acid)/chitosan (PLA/CS) blend and a PLA/CS blend containing silver (Ag) nanoparticles (Ag/PLA/CS) were prepared using an electrospinning technique. The morphology of electrospun fibers was observed by field emission scanning electron microscopy. The addition of AgNO3 to the PLA/CS blend solution improved the electrospinning ability of the PLA/CS blend. The average diameters of the electrospun PLA/CS and Ag/PLA/CS blend fibers decreased as CS content increased. The Ag particles were evenly distributed in PLA/CS ultrafine fibers observed under transmission electron microscopy. Ag nanoparticles were spontaneously generated during the electrospinning process. When the CS content in the blend increased, the size of the Ag nanoparticles on the surface of the electrospun fibers increased as well. The thermal and mechanical properties of the nonwoven mats were examined by differential scanning calorimetry and a tensile tester. Fourier transform infrared spectroscopy was used to characterize the molecular interactions among PLA, Ag, and CS in the blends. The antibacterial activity of the nonwoven mats against Escherichia coli and Staphylococcus aureus was studied using an optical density method. © 2012 The Polymer Society of Korea and Springer Netherlands.


Nguyen C.M.,Korean University of Science and Technology | Nguyen C.M.,Korea Research Institute of Chemical Technology | Kim J.-S.,Korea Research Institute of Chemical Technology | Nguyen T.N.,Vietnam Institute of Industrial Chemistry | And 6 more authors.
Bioresource Technology | Year: 2013

Simultaneous saccharification and cofermentation (SSCF) of Curcuma longa waste biomass obtained after turmeric extraction to l- and d-lactic acid by Lactobacillus coryniformis and Lactobacillus paracasei, respectively, was investigated. This is a rich, starchy, agro-industrial waste with potential for use in industrial applications. After optimizing the fermentation of the biomass by adjusting nitrogen sources, enzyme compositions, nitrogen concentrations, and raw material concentrations, the SSCF process was conducted in a 7-l jar fermentor at 140. g dried material/L. The maximum lactic acid concentration, average productivity, reducing sugar conversion and lactic acid yield were 97.13. g/L, 2.7. g/L/h, 95.99% and 69.38. g/100. g dried material for l-lactic acid production, respectively and 91.61. g/L, 2.08. g/L/h, 90.53% and 65.43. g/100. g dried material for d-lactic acid production, respectively. The simple and efficient process described in this study could be utilized by C. longa residue-based lactic acid industries without requiring the alteration of plant equipment. © 2013 Elsevier Ltd.


Tran T.T.T.,Vietnam Institute of Industrial Chemistry | Vu T.T.H.,Vietnam Institute of Industrial Chemistry | Nguyen T.H.,Vietnam Academy of Science and Technology
Materials Letters | Year: 2013

A green approach for the synthesis of silver nanoparticles (AgNPs) using aqueous leaf extract of Tithonia diversifolia under ambient conditions was studied. The effect of pH on biosynthesis of AgNPs was investigated by UV-vis spectrophotometer. TEM images showed that the diameter of stable AgNPs was approximately 25 nm. TG-DTA analysis revealed that content of biomolecules surrounding silver was about 24.2%. Moreover the antimicrobial activity of synthesized AgNPs against Pseudomonas aeruginosa, Microbacterium foliorum, Bacillus subtilis, and Rhodococcus equi was screened. © 2013 Elsevier B.V.


Nguyen H.K.D.,Hanoi University of Science and Technology | Pham V.V.,Vietnam Oil and Gas Group | Do H.T.,Vietnam Institute of Industrial Chemistry
Catalysis Letters | Year: 2016

Abstract: A new catalyst for hydrotreating process mainly including hydrodeoxygenation (HDO) and hydrodenitrogenation (HDN) was prepared by introducing Ni onto the surface of biochar obtained from microalgae biomass pyrolysis. The co-product bio-oil obtained from the pyrolysis was treated under H2 pressure on the as-synthesized Ni/biochar catalyst. The whole process was established in a close loop cycle illustrating its high efficiency in comparison to other HDO or HDN processes. The catalyst was prepared through two-step procedure including biochar production and impregnating of Ni precursor onto the biochar. The pyrolysis of microalgal biomass was established at 400 °C for 2 h producing mainly the biochar and the bio-oil. The biochar was then doped with Ni2+ by incipient wetness impregnation followed by drying and calcination at suitable temperature for a certain time. The upgrading process including hydrodeoxygenation (HDO) and hydrodenitrogenation (HDN) reactions of bio-oil obtained from microalgal pyrolysis was investigated at various parameters such as temperature, time, catalyst dosage and stirring speed for converting bio-oil obtained from microalgal pyrolysis to rich hydrocarbon product. The Ni/biochar catalyst synthesized from the biochar through impregnation was used in the upgrading process. The results showed that the Ni/biochar catalyst could be very effective in the upgrading process producing mainly n-heptadecane as a very important component of diesel fuel. Some techniques were applied for characterizing the catalyst, feedstock and product such as XRD, H2-TPR, GC-MS and some standard ASTM methods. Graphical Abstract: [Figure not available: see fulltext.] © 2016 Springer Science+Business Media New York


Thanh L.X.,Hanoi University of Science and Technology | Phuong P.T.M.,Vietnam Institute of Industrial Chemistry
e-Journal of Surface Science and Nanotechnology | Year: 2012

Pure-phase cerium-doped yttrium silicate and yttrium disilicate phosphors were successfully synthesized by the sol-gel method with added ammonia when the precursor was calcined at 1100°C and 1300°C for 1 h. The blue light was emitted when excited by the UV radiation of 325 nm wavelength. The luminescence of Y 2SiO 5:Ce1% phosphors was less than that of Y 2Si 2O 7:Ce1% in the same synthetic condition. Besides, their photoluminescence was strongly increased when Li, Na or K sensitizers were added. The X 1-Y 2SiO 5 and X 2-Y 2SiO 5 phosphors were irregular shapes and composed of agglomerates with the particle size of approximately 70 nm to 100 nm. © 2012 The Surface Science Society of Japan.

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