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Otto Holst - One of the best experts on this subject based on the ideXlab platform.

  • characterization of a novel lipid a containing d galacturonic Acid that replaces phosphate residues the structure of the lipid a of the lipopolysaccharide from the hyperthermophilic bacterium aquifex pyrophilus
    Journal of Biological Chemistry, 2000
    Co-Authors: Barbara M Plotz, Buko Lindner, Karl O Stetter, Otto Holst
    Abstract:

    Abstract According to the 16 S rRNA phylogenetic tree, the hyperthermophilic bacterium Aquifex pyrophilus represents the deepest and shortest branching species of the kingdomBacteria. We show for the first time that an organism, which is phylogenetically ancient on the basis of its 16 S rRNA and that exists at extreme conditions, may contain lipopolysaccharide (LPS). The LPS was extracted from dried bacteria using a modified phenol/water method. SDS-polyacrylamide gel electrophoresis and silver stain displayed a ladder-like pattern, which is typical for smooth-form LPS (possessing an O-specific polysaccharide). The molecular masses of the LPS populations were determined by matrix-assisted laser-desorption ionization mass spectrometry. Lipid A was precipitated after mild Acid hydrolysis of LPS. Its complete structure was determined by chemical analyses, combined gas-liquid chromatography-mass spectrometry, matrix-assisted laser-desorption ionization mass spectrometry, and one- and two-dimensional NMR spectroscopy. The lipid A consists of a β-(1→6)-linked 2,3-diamino-2,3-dideoxy-d-glucopyranose (DAG) disaccharide carrying two residues each of (R)-3-hydroxytetradecanoic Acid and (R)-3-hydroxyhexadecanoic Acid in amide linkage and one residue of Octadecanoic Acid in ester linkage. Each DAG moiety carries one residue of each 3-hydroxytetradecanoic and 3-hydroxyhexadecanoic Acid. In the nonreducing DAG, the Octadecanoic Acid is attached to the 3-hydroxy group of 3-hydroxytetradecanoic Acid. Each DAG is substituted by one d-galacturonic Acid residue, which is linked toO-1 of the reducing and to O-4 of the nonreducing end. This structure represents a novel type of lipid A.

  • characterization of a novel lipid a containing d galacturonic Acid that replaces phosphate residues the structure of the lipid a of the lipopolysaccharide from the hyperthermophilic bacterium aquifex pyrophilus
    Journal of Biological Chemistry, 2000
    Co-Authors: Barbara M Plotz, Buko Lindner, Karl O Stetter, Otto Holst
    Abstract:

    According to the 16 S rRNA phylogenetic tree, the hyperthermophilic bacterium Aquifex pyrophilus represents the deepest and shortest branching species of the kingdom Bacteria. We show for the first time that an organism, which is phylogenetically ancient on the basis of its 16 S rRNA and that exists at extreme conditions, may contain lipopolysaccharide (LPS). The LPS was extracted from dried bacteria using a modified phenol/water method. SDS-polyacrylamide gel electrophoresis and silver stain displayed a ladder-like pattern, which is typical for smooth-form LPS (possessing an O-specific polysaccharide). The molecular masses of the LPS populations were determined by matrix-assisted laser-desorption ionization mass spectrometry. Lipid A was precipitated after mild Acid hydrolysis of LPS. Its complete structure was determined by chemical analyses, combined gas-liquid chromatography-mass spectrometry, matrix-assisted laser-desorption ionization mass spectrometry, and one- and two-dimensional NMR spectroscopy. The lipid A consists of a beta-(1-->6)-linked 2,3-diamino-2,3-dideoxy-D-glucopyranose (DAG) disaccharide carrying two residues each of (R)-3-hydroxytetradecanoic Acid and (R)-3-hydroxyhexadecanoic Acid in amide linkage and one residue of Octadecanoic Acid in ester linkage. Each DAG moiety carries one residue of each 3-hydroxytetradecanoic and 3-hydroxyhexadecanoic Acid. In the nonreducing DAG, the Octadecanoic Acid is attached to the 3-hydroxy group of 3-hydroxytetradecanoic Acid. Each DAG is substituted by one D-galacturonic Acid residue, which is linked to O-1 of the reducing and to O-4 of the nonreducing end. This structure represents a novel type of lipid A.

Yu-qun Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Antibacterial Activity of 9-Octadecanoic Acid-Hexadecanoic Acid-Tetrahydrofuran-3,4-Diyl Ester from Neem Oil
    Agricultural Sciences in China, 2010
    Co-Authors: Yu-qun Zhang, Zhongqiong Yin, Renyong Jia, Fan Yang
    Abstract:

    Abstract The 9-Octadecanoic Acid-hexadecanoic Acid-tetrahydrofuran-3,4-diyl ester from neem oil was investigated for antibacterial activity against three bacterial strains viz ., Staphylococcus aureus ATCC No. 25923, Escherichia coli ATCC No. 44102 and Salmonella sp. ATCC No. 50 041 in vitro . The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of the 9-Octadecanoic Acid-hexadecanoic Acid-tetrahydrofuran-3,4-diyl ester were determined by using the broth microdilution dilution (BMD) method at different concentrations ranging from 20 to 0.625 mg mL −1 . Its time-inhibition curve against E. coli was also tested and showed that the MIC values for the bacterial strains S. aureus, E. coli and Salmonella sp. were 20, 5 and 10 mg mL −1 , respectively. Its MBC values were 20, 20 and 10 mg mL −1 , respectively. The antibacterial activity of 9-Octadecanoic Acid-hexadecanoic Acid-tetrahydrofuran-3,4-diyl ester against three strain tested showed the relationship with time and concentration.

  • acaricidal activity of four fractions and Octadecanoic Acid tetrahydrofuran 3 4 diyl ester isolated from chloroform extracts of neem azadirachta indica oil against sarcoptes scabiei var cuniculi larvae in vitro
    Veterinary Parasitology, 2009
    Co-Authors: Yonghua Du, Jinliang Li, Xuting Li, Cheng Lv, Gang Ye, Li Zhang, Yu-qun Zhang
    Abstract:

    Abstract Four fractions obtained from chloroform extracts of neem ( Azadirachta indica ) oil by column chromatography were investigated for acaricidal activity against Sarcoptes scabiei var. cuniculi larvae in vitro . Octadecanoic Acid-tetrahydrofuran-3,4-diyl ester was isolated from an active fraction of the chloroform extract and its toxicity against S. scabiei larvae was tested in vitro . A complementary log–log model was used to analyse the toxicity data. Activity was found in the third fraction, with 100% corrected mortality after 4.5 h of exposure at a concentration of 200 mg ml −1 . This fraction was repeatedly re-crystallised in acetone to yield a white amorphous powder, identified as Octadecanoic Acid-tetrahydrofuran-3,4-diyl ester, with a median lethal concentration (LC 50 ) of 0.1 mg ml −1 at 24 h post-treatment. The median lethal time (LT 50 ) for this compound was 15.3 h at a concentration of 7.5 mg ml −1 .

Barbara M Plotz - One of the best experts on this subject based on the ideXlab platform.

  • characterization of a novel lipid a containing d galacturonic Acid that replaces phosphate residues the structure of the lipid a of the lipopolysaccharide from the hyperthermophilic bacterium aquifex pyrophilus
    Journal of Biological Chemistry, 2000
    Co-Authors: Barbara M Plotz, Buko Lindner, Karl O Stetter, Otto Holst
    Abstract:

    Abstract According to the 16 S rRNA phylogenetic tree, the hyperthermophilic bacterium Aquifex pyrophilus represents the deepest and shortest branching species of the kingdomBacteria. We show for the first time that an organism, which is phylogenetically ancient on the basis of its 16 S rRNA and that exists at extreme conditions, may contain lipopolysaccharide (LPS). The LPS was extracted from dried bacteria using a modified phenol/water method. SDS-polyacrylamide gel electrophoresis and silver stain displayed a ladder-like pattern, which is typical for smooth-form LPS (possessing an O-specific polysaccharide). The molecular masses of the LPS populations were determined by matrix-assisted laser-desorption ionization mass spectrometry. Lipid A was precipitated after mild Acid hydrolysis of LPS. Its complete structure was determined by chemical analyses, combined gas-liquid chromatography-mass spectrometry, matrix-assisted laser-desorption ionization mass spectrometry, and one- and two-dimensional NMR spectroscopy. The lipid A consists of a β-(1→6)-linked 2,3-diamino-2,3-dideoxy-d-glucopyranose (DAG) disaccharide carrying two residues each of (R)-3-hydroxytetradecanoic Acid and (R)-3-hydroxyhexadecanoic Acid in amide linkage and one residue of Octadecanoic Acid in ester linkage. Each DAG moiety carries one residue of each 3-hydroxytetradecanoic and 3-hydroxyhexadecanoic Acid. In the nonreducing DAG, the Octadecanoic Acid is attached to the 3-hydroxy group of 3-hydroxytetradecanoic Acid. Each DAG is substituted by one d-galacturonic Acid residue, which is linked toO-1 of the reducing and to O-4 of the nonreducing end. This structure represents a novel type of lipid A.

  • characterization of a novel lipid a containing d galacturonic Acid that replaces phosphate residues the structure of the lipid a of the lipopolysaccharide from the hyperthermophilic bacterium aquifex pyrophilus
    Journal of Biological Chemistry, 2000
    Co-Authors: Barbara M Plotz, Buko Lindner, Karl O Stetter, Otto Holst
    Abstract:

    According to the 16 S rRNA phylogenetic tree, the hyperthermophilic bacterium Aquifex pyrophilus represents the deepest and shortest branching species of the kingdom Bacteria. We show for the first time that an organism, which is phylogenetically ancient on the basis of its 16 S rRNA and that exists at extreme conditions, may contain lipopolysaccharide (LPS). The LPS was extracted from dried bacteria using a modified phenol/water method. SDS-polyacrylamide gel electrophoresis and silver stain displayed a ladder-like pattern, which is typical for smooth-form LPS (possessing an O-specific polysaccharide). The molecular masses of the LPS populations were determined by matrix-assisted laser-desorption ionization mass spectrometry. Lipid A was precipitated after mild Acid hydrolysis of LPS. Its complete structure was determined by chemical analyses, combined gas-liquid chromatography-mass spectrometry, matrix-assisted laser-desorption ionization mass spectrometry, and one- and two-dimensional NMR spectroscopy. The lipid A consists of a beta-(1-->6)-linked 2,3-diamino-2,3-dideoxy-D-glucopyranose (DAG) disaccharide carrying two residues each of (R)-3-hydroxytetradecanoic Acid and (R)-3-hydroxyhexadecanoic Acid in amide linkage and one residue of Octadecanoic Acid in ester linkage. Each DAG moiety carries one residue of each 3-hydroxytetradecanoic and 3-hydroxyhexadecanoic Acid. In the nonreducing DAG, the Octadecanoic Acid is attached to the 3-hydroxy group of 3-hydroxytetradecanoic Acid. Each DAG is substituted by one D-galacturonic Acid residue, which is linked to O-1 of the reducing and to O-4 of the nonreducing end. This structure represents a novel type of lipid A.

Russell J. Crawford - One of the best experts on this subject based on the ideXlab platform.

  • Molecular Organization of the Nanoscale Surface Structures of the Dragonfly Hemianax papuensis Wing Epicuticle
    PloS one, 2013
    Co-Authors: Elena P. Ivanova, Song Ha Nguyen, Hayden K. Webb, Jafar Hasan, Vi Khanh Truong, Robert N. Lamb, Xiaofei Duan, Mark J. Tobin, Peter J. Mahon, Russell J. Crawford
    Abstract:

    The molecular organization of the epicuticle (the outermost layer) of insect wings is vital in the formation of the nanoscale surface patterns that are responsible for bestowing remarkable functional properties. Using a combination of spectroscopic and chromatographic techniques, including Synchrotron-sourced Fourier-transform infrared microspectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS) depth profiling and gas chromatography-mass spectrometry (GCMS), we have identified the chemical components that constitute the nanoscale structures on the surface of the wings of the dragonfly, Hemianax papuensis. The major components were identified to be fatty Acids, predominantly hexadecanoic Acid and Octadecanoic Acid, and n-alkanes with even numbered carbon chains ranging from C14 to C30. The data obtained from XPS depth profiling, in conjunction with that obtained from GCMS analyses, enabled the location of particular classes of compounds to different regions within the epicuticle. Hexadecanoic Acid was found to be a major component of the outer region of the epicuticle, which forms the surface nanostructures, and was also detected in deeper layers along with Octadecanoic Acid. Aliphatic compounds were detected throughout the epicuticle, and these appeared to form a third discrete layer that was separate from both the inner and outer epicuticles, which has never previously been reported.

Elena P. Ivanova - One of the best experts on this subject based on the ideXlab platform.

  • Molecular Organization of the Nanoscale Surface Structures of the Dragonfly Hemianax papuensis Wing
    2016
    Co-Authors: Wing Epicuticle, Elena P. Ivanova, Song Ha Nguyen, Hayden K. Webb, Vi Khanh Truong, See Profile, Russell Crawford, Jafar Hasan
    Abstract:

    The molecular organization of the epicuticle (the outermost layer) of insect wings is vital in the formation of the nanoscale surface patterns that are responsible for bestowing remarkable functional properties. Using a combination of spectroscopic and chromatographic techniques, including Synchrotron-sourced Fourier-transform infrared microspectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS) depth profiling and gas chromatography-mass spectrometry (GCMS), we have identified the chemical components that constitute the nanoscale structures on the surface of the wings of the dragonfly, Hemianax papuensis. The major components were identified to be fatty Acids, predominantly hexadecanoic Acid and Octadecanoic Acid, and n-alkanes with even numbered carbon chains ranging from C14 to C30. The data obtained from XPS depth profiling, in conjunction with that obtained from GCMS analyses, enabled the location of particular classes of compounds to different regions within the epicuticle. Hexadecanoic Acid was found to be a major component of the outer region of th

  • Molecular Organization of the Nanoscale Surface Structures of the Dragonfly Hemianax papuensis Wing Epicuticle
    PloS one, 2013
    Co-Authors: Elena P. Ivanova, Song Ha Nguyen, Hayden K. Webb, Jafar Hasan, Vi Khanh Truong, Robert N. Lamb, Xiaofei Duan, Mark J. Tobin, Peter J. Mahon, Russell J. Crawford
    Abstract:

    The molecular organization of the epicuticle (the outermost layer) of insect wings is vital in the formation of the nanoscale surface patterns that are responsible for bestowing remarkable functional properties. Using a combination of spectroscopic and chromatographic techniques, including Synchrotron-sourced Fourier-transform infrared microspectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS) depth profiling and gas chromatography-mass spectrometry (GCMS), we have identified the chemical components that constitute the nanoscale structures on the surface of the wings of the dragonfly, Hemianax papuensis. The major components were identified to be fatty Acids, predominantly hexadecanoic Acid and Octadecanoic Acid, and n-alkanes with even numbered carbon chains ranging from C14 to C30. The data obtained from XPS depth profiling, in conjunction with that obtained from GCMS analyses, enabled the location of particular classes of compounds to different regions within the epicuticle. Hexadecanoic Acid was found to be a major component of the outer region of the epicuticle, which forms the surface nanostructures, and was also detected in deeper layers along with Octadecanoic Acid. Aliphatic compounds were detected throughout the epicuticle, and these appeared to form a third discrete layer that was separate from both the inner and outer epicuticles, which has never previously been reported.