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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. Source


Dang Q.L.,Korea Research Institute of Chemical Technology | Dang Q.L.,Chungnam National University | Kwon H.R.,Korea Research Institute of Chemical Technology | Choi Y.H.,Korea Research Institute of Chemical Technology | And 6 more authors.
Nematology | Year: 2010

Methanol extracts of 50 plant species were assessed for nematicidal activity against the pine wood nematode (PWN), Bursaphelenchus xylophilus. Out of these, five extracts: Justicia diclipteroides subsp. usambarica; Nerium oleander; Persea americana; Scadoxus multiflorus subsp. multiflorus; and Thespesia populnea, caused 96-100% mortalities of pine wood nematode at 1000 μg ml-1 for 48 h. Methanol extract of the stem bark of P. americana (avocado) and the n-hexane layer obtained from the methanol extract by solvent partitioning caused 100% mortality of PWN at low concentrations of 125 and 63 μg ml-1, respectively. One potent nematicidal compound was isolated from the stem bark of P. americana and its chemical structure was determined to be isoobtusilactone A (1) by mass and NMR spectral analyses. The chemical showed a very strong nematicidal activity against PWN; it caused mortalities of over 97% at concentrations higher than 50 μg ml-1. Compared with a commercial synthetic nematicide, morantel tartrate, compound 1 showed a little more potent activity. The results suggested that compound 1 may have the potential to be explored as a natural nematicide or be useful as a lead molecule for development of new nematicidal agents for controlling the pine wilt disease caused by B. xylophilus. © 2010 Brill Academic Publishers. Source


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. Source


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. Source


Le Dang Q.,Korea Research Institute of Chemical Technology | Le Dang Q.,Vietnam Institute of Industrial Chemistry | Shin T.S.,Dongbu Farm Hannong Co. | 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. Source

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