scholarly journals O-Methyl sugars in lipopolysaccharides of Rhodospirillacea. Identification of 3-O-methyl-d-mannose in Rhodopseudomonas viridis and of 4-O-methyl-d-xylose and 3-O-methyl-6-deoxy-d-talose in Rhodopseudomonas palustris respectively

1973 ◽  
Vol 135 (2) ◽  
pp. 293-297 ◽  
Author(s):  
Jürgen Weckesser ◽  
Hubert Mayer ◽  
Inge Fromme
Keyword(s):  
Mass Spectrometry ◽  
Paper Chromatography ◽  
High Voltage ◽  
Optical Rotation ◽  
Rhodopseudomonas Palustris ◽  
Rhodopseudomonas Viridis ◽  
Gram Negative ◽  
Optical Configuration ◽  
Alditol Acetates ◽  
High Voltage Electrophoresis

1. This paper deals with the identification of three O-methyl sugars in lipopolysaccharides isolated from strains of the Gram-negative photosynthetic family Rhodospirillaceae. In addition to the previously described 3-O-methyl-l-xylose, a second O-methyl sugar was encountered in the lipopolysaccharide of Rhodopseudomonas viridis F, namely 3-O-methyl-d-mannose. The lipopolysaccharides of two strains of Rhodopseudomonas palustris (strain 1e5 and 8/1) contain two O-methylsugars, 4-O-methyl-d-xylose and 3-O-methyl-6-deoxy-d-talose (d-acovenose). 4-O-Methyl-d-xylose, but not 3-O-methyl-6-deoxy-d-talose, could be identified in the lipopolysaccharides of the strains K/1 and 2/2 of the same species. 2. The O-methyl sugars described in this communication were isolated by paper chromatography and identified by g.l.c., paper chromatography, high-voltage electrophoresis and mass spectrometry. Besides the genuine sugars, their alditol acetates and their demethylated (parental) forms were investigated. Optical rotation measurements and, in one case, enzymic reactions were used to establish the optical configuration of the sugars under investigation.

ISOLATION AND STRUCTURE OF URIDINE NUCLEOTIDE-PEPTIDES FROM AEROBACTER CLOACAE NRC 492

1963 ◽  
Vol 41 (1) ◽  
pp. 1065-1072 ◽  
Author(s):  
R. A. Anwar ◽  
C. Roy ◽  
R. W. Watson
Keyword(s):  
Lactic Acid ◽  
Amino Acid ◽  
Lithium Chloride ◽  
Paper Chromatography ◽  
High Voltage ◽  
Chloride Solutions ◽  
Uridine Nucleotide ◽  
Ethanol Extracts ◽  
Dowex 1 ◽  
High Voltage Electrophoresis

Four closely related uridine nucleotide-peptides isolated from ethanol extracts of penicillin-treated Aerobacter cloacae NRC 492 have been partially characterized. Fractionation of dialyzed extracts on Dowex-1-Cl columns with aqueous lithium chloride solutions, precipitation of the nucleotide-peptides with methanol–acetone, and further separation by paper chromatography and high voltage electrophoresis yielded (a) UDP-GNAc-lact.L-ala.D-glu.meso-dap.D-ala,* (b) UDP-GNAc-lact.L-ala.D-glu.meso-dap, (c) UDP-GNAc-lact.L-ala.D-glu., and (d) UDP-GNAc-lactic acid. The amino acid isomers were identified by micro-enzymic and chromatographic methods.

ISOLATION AND STRUCTURE OF URIDINE NUCLEOTIDE-PEPTIDES FROM AEROBACTER CLOACAE NRC 492

1963 ◽  
Vol 41 (4) ◽  
pp. 1065-1072 ◽  
Author(s):  
R. A. Anwar ◽  
C. Roy ◽  
R. W. Watson
Keyword(s):  
Lactic Acid ◽  
Amino Acid ◽  
Lithium Chloride ◽  
Paper Chromatography ◽  
High Voltage ◽  
Chloride Solutions ◽  
Uridine Nucleotide ◽  
Ethanol Extracts ◽  
Dowex 1 ◽  
High Voltage Electrophoresis

Four closely related uridine nucleotide-peptides isolated from ethanol extracts of penicillin-treated Aerobacter cloacae NRC 492 have been partially characterized. Fractionation of dialyzed extracts on Dowex-1-Cl columns with aqueous lithium chloride solutions, precipitation of the nucleotide-peptides with methanol–acetone, and further separation by paper chromatography and high voltage electrophoresis yielded (a) UDP-GNAc-lact.L-ala.D-glu.meso-dap.D-ala,* (b) UDP-GNAc-lact.L-ala.D-glu.meso-dap, (c) UDP-GNAc-lact.L-ala.D-glu., and (d) UDP-GNAc-lactic acid. The amino acid isomers were identified by micro-enzymic and chromatographic methods.

Structural analysis of oligomeric fructans from excised leaves of Lolium temulentum

2020 ◽  
Author(s):  
Ian Sims ◽  
CJ Pollock ◽  
R Horgan
Keyword(s):  
Mass Spectrometry ◽  
Structural Analysis ◽  
Higher Plants ◽  
Water Soluble ◽  
Lolium Temulentum ◽  
Neutral Water ◽  
Alditol Acetates ◽  
Partially Methylated

Individual fructan tri-, tetra- and pentasaccharide isomers in neutral, water-soluble extracts from Lolium temulentum were purified and the linkages present in these isomeric oligosaccharides were analysed by combined GC-mass spectrometry of partially methylated alditol acetates. 1-Kestose and neokestose were the most abundant trisaccharides with 6-kestose present in much lower amounts. Analysis of isomers of DP 4 and 5 showed that multiple linkage types were present with structures based on all three trisaccharides. Oligosaccharides based on neokestose but with 2,6 linkages between adjacent fructose residues have not been previously detected in higher plants. © 1992.

scholarly journals Two New Phomaligols from the Marine-Derived Fungus Aspergillus flocculosus and Their Anti-Neuroinflammatory Activity in BV-2 Microglial Cells

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 65
Author(s):  
Byeoung-Kyu Choi ◽  
Duk-Yeon Cho ◽  
Dong-Kug Choi ◽  
Phan Thi Hoai Trinh ◽  
Hee Jae Shin
Keyword(s):  
Nitric Oxide ◽  
Mass Spectrometry ◽  
Optical Rotation ◽  
Chemical Oxidation ◽  
Culture Broth ◽  
Membered Ring ◽  
Microglial Cells ◽  
No Production ◽  
Nmr Data ◽  
Ic50 Value

Two new phomaligols, deketo-phomaligol A (1) and phomaligol E (2), together with six known compounds (3–8) were isolated from the culture broth of the marine-derived fungus Aspergillus flocculosus. Compound 1 was first isolated as a phomaligol derivative possessing a five-membered ring. The structures and absolute configurations of the new phomaligols were determined by detailed analyses of mass spectrometry (MS), nuclear magnetic resonance (NMR) data, optical rotation values and electronic circular dichroism (ECD). In addition, the absolute configurations of the known compounds 3 and 4 were confirmed by chemical oxidation and comparison of optical rotation values. Isolated compounds at a concentration of 100 μM were screened for inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. Among the compounds, 4 showed moderate anti-neuroinflammatory effects with an IC50 value of 56.6 μM by suppressing the production of pro-inflammatory mediators in activated microglial cells without cytotoxicity.

scholarly journals Analyses of Lipid A Diversity in Gram-Negative Intestinal Bacteria Using Liquid Chromatography–Quadrupole Time-of-Flight Mass Spectrometry

Metabolites ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 197
Author(s):  
Nobuyuki Okahashi ◽  
Masahiro Ueda ◽  
Fumio Matsuda ◽  
Makoto Arita
Keyword(s):  
Mass Spectrometry ◽  
Immune Response ◽  
Liquid Chromatography ◽  
Mammalian Cells ◽  
Lipid A ◽  
Acyl Chain ◽  
Time Of Flight ◽  
Intestinal Bacteria ◽  
Gram Negative ◽  
Flight Mass Spectrometry

Lipid A is a characteristic molecule of Gram-negative bacteria that elicits an immune response in mammalian cells. The presence of structurally diverse lipid A types in the human gut bacteria has been suggested before, and this appears associated with the immune response. However, lipid A structures and their quantitative heterogeneity have not been well characterized. In this study, a method of analysis for lipid A using liquid chromatography–quadrupole time-of-flight mass spectrometry (LC-QTOF/MS) was developed and applied to the analyses of Escherichia coli and Bacteroidetes strains. In general, phosphate compounds adsorb on stainless-steel piping and cause peak tailing, but the use of an ammonia-containing alkaline solvent produced sharp lipid A peaks with high sensitivity. The method was applied to E. coli strains, and revealed the accumulation of lipid A with abnormal acyl side chains in knockout strains as well as known diphosphoryl hexa-acylated lipid A in a wild-type strain. The analysis of nine representative strains of Bacteroidetes showed the presence of monophosphoryl penta-acylated lipid A characterized by a highly heterogeneous main acyl chain length. Comparison of the structures and amounts of lipid A among the strains suggested a relationship between lipid A profiles and the phylogenetic classification of the strains.

RADIOCARBON IN MEXICO: FROM PROPORTIONAL COUNTERS TO AMS

Radiocarbon ◽  
2021 ◽  
pp. 1-7
Author(s):  
Corina Solís ◽  
Efraín Chávez ◽  
Arcadio Huerta ◽  
María Esther Ortiz ◽  
Alberto Alcántara ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
High Voltage ◽  
Accelerator Mass Spectrometry ◽  
Science And Technology ◽  
National Council ◽  
University Of Arizona ◽  
Technological Developments ◽  
High Voltage Engineering ◽  
The University

ABSTRACT Augusto Moreno is credited with establishing the first radiocarbon (14C) laboratory in Mexico in the 1950s, however, 14C measurement with the accelerator mass spectrometry (AMS) technique was not achieved in our country until 2003. Douglas Donahue from the University of Arizona, a pioneer in using AMS for 14C dating, participated in that experiment; then, the idea of establishing a 14C AMS laboratory evolved into a feasible project. This was finally reached in 2013, thanks to the technological developments in AMS and sample preparation with automated equipment, and the backing and support of the National Autonomous University of Mexico and the National Council for Science and Technology. The Mexican AMS Laboratory, LEMA, with a compact 1 MV system from High Voltage Engineering Europa, and its sample preparation laboratories with IonPlus automated graphitization equipment, is now a reality.

High-voltage electrophoresis of choline and its esters

1974 ◽  
Vol 89 (1) ◽  
pp. 96-98 ◽  
Author(s):  
Sheila E. Brooker ◽  
Keith J. Harkiss
Keyword(s):  
High Voltage ◽  
High Voltage Electrophoresis
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