Precise metabolic flux analysis of coryneform bacteria by gas chromatography–mass spectrometry and verification by nuclear magnetic resonance

2006 ◽  
Vol 102 (5) ◽  
pp. 413-424 ◽  
Author(s):  
Tomokazu Shirai ◽  
Kunihiro Matsuzaki ◽  
Masanori Kuzumoto ◽  
Keisuke Nagahisa ◽  
Chikara Furusawa ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Gas Chromatography ◽  
Magnetic Resonance ◽  
Metabolic Flux Analysis ◽  
Metabolic Flux ◽  
Gas Chromatography Mass Spectrometry ◽  
Flux Analysis ◽  
Coryneform Bacteria ◽  
Chromatography Mass Spectrometry

Comparison of hydrogenolysis with thioacidolysis for lignin structural analysis

Holzforschung ◽  
2014 ◽  
Vol 68 (2) ◽  
pp. 151-155 ◽  
Author(s):  
Daniel J. van de Pas ◽  
Bernadette Nanayakkara ◽  
Ian D. Suckling ◽  
Kirk M. Torr
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Gas Chromatography ◽  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Magnetic Resonance ◽  
Gas Chromatography Mass Spectrometry ◽  
Aryl Ether ◽  
Chromatography Mass Spectrometry

Abstract Mild hydrogenolysis has been compared with thioacidolysis as a method for degrading lignins in situ and in isolated form before analysis by gas chromatography/mass spectrometry and quantitative 31P nuclear magnetic resonance (NMR) spectroscopy. Both degradation methods gave similar levels of β-aryl ether-linked phenylpropane units that were released as monomers. Degradation by hydrogenolysis generally gave lower levels of total phenylpropane units when analyzed by 31P NMR, especially in the case of lignins with high levels of condensed units. Overall, these results indicate that mild hydrogenolysis could offer an alternative to thioacidolysis for probing lignin structure.

68 Flux analysis of aerobic glycolysis in bovine blastocysts and CT1 cells

2019 ◽  
Vol 31 (1) ◽  
pp. 159
Author(s):  
J. Chung ◽  
R. Clifford ◽  
G. Sriram ◽  
C. Keefer
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Metabolic Flux ◽  
Aerobic Glycolysis ◽  
Carbon Sources ◽  
Pentose Phosphate ◽  
Gas Chromatography Mass Spectrometry ◽  
Flux Analysis ◽  
Metabolic Modelling ◽  
Chromatography Mass Spectrometry

Embryo quality and maternal recognition are crucial for successful initiation of bovine pregnancy. Previous studies have proposed that better quality embryos use aerobic glycolysis to meet a high demand for biomass components. While hexoses are the principal carbon sources that provide energy to glycolysis, little is known about partitioning of hexoses into metabolic pathways or alteration of partitioning when different hexoses are simultaneously available. Specific metabolic utilisation of 13C-labelled substrates can be quantified by gas chromatography-mass spectrometry, an excellent noninvasive approach for studying cellular metabolism. To assess hexose flux through central metabolism, bovine blastocysts and CT1 cells (a bovine trophectoderm cell line) were cultured in SOF-based media supplemented with combinations of 50% uniformly labelled (U) and 50% naturally abundant (NA) glucose (Glc) or fructose (Fru) (U−13C Glc+NA Glc, U−13C Fru+NA Fru, U−13C Glc+NA Fru, and U−13C Fru+NA Glc), such that total hexose concentration was 1.5mM. Metabolites in spent media from 24-h cultures of single or 5 blastocysts (40-μL drops; 5% CO2, 5% O2, 90% N2) and 1-, 2-, 3-, 6-, 8-, and 24-h incubations of CT1 cells (150 μL; ~3×104 cells per well; 5% CO2, 95% air) were extracted with a MeOH-CHCl3 reagent, derivatized, and analysed by gas chromatography-mass spectrometry. Measurement of mass isotopomer distributions of metabolites, chiefly pyruvate, lactate, and amino acids, followed by correction for natural abundances and metabolic modelling, revealed several insights. For instance, five Day 7 or Day 8 blastocysts (Day 0=fertilization) supplied with U−13C Glc+NA Fru displayed 13C enrichments of 80.3%±1.4% for pyruvate and 71.6%±2.8% for lactate, whereas when supplied with U−13C Fru+NA Glc, they displayed lower 13C enrichments of 5.7%±2.4% for pyruvate and 2.8%±0.4% lactate (mean±standard deviation, n=3 to 4). Metabolic modelling revealed that when Glc and Fru are simultaneously available, the blastocysts used 2.5±0.2 moles of Fru per 100 moles of Glc used. Furthermore, 13C enrichment of pyruvate was 42.0±0.6% when U−13C Glc+NA Glc was supplied and 37.8±2.7% when U−13C Fru+NA Fru was supplied. Lactate enrichments followed a similar trend. This indicates that, individually, Glc and Fru were utilised majorly through aerobic glycolysis with some involvement of the pentose phosphate pathway. Alanine was negligibly labelled in all of the experiments, suggesting either a low TCA flux or that alanine is diluted by extra- or intracellular amino or fatty acids. Single blastocysts and CT1 cells showed a similar labelling pattern when hexoses were available. Following Glc depletion at 8h in CT1 cultures, the 13C enrichments of alanine and citrate in the media increased, suggesting a sharp alteration of metabolic state. These findings demonstrate that metabolic flux can be comprehensively analysed for single bovine blastocysts and CT1 cell metabolism models that of the blastocyst. This project was supported by Agriculture and Food Research Initiative Competitive Grant no. 2015-67015-23237 from the USDA National Institute of Food and Agriculture.

scholarly journals Chemical Composition of Needle, Cone, and Branch Oils From Vietnamese Pinus cernua

2019 ◽  
Vol 14 (5) ◽  
pp. 1934578X1985099 ◽  
Author(s):  
Tran Hui Thai ◽  
Nguyen Thi Hien ◽  
Le Ngoc Diep ◽  
Mathieu Paoli ◽  
Joseph Casanova ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Gas Chromatography ◽  
Chemical Composition ◽  
Magnetic Resonance ◽  
Retention Index ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Main Component ◽  
Pine Species

Conifers are well represented in Vietnam where a new pine species has been recently discovered in Son La province: Pinus cernua, synonym P. armandii ssp. xuannhaensis. The compositions of needle, cone, and branch oils have been investigated by gas chromatography (retention index), gas chromatography-mass spectrometry, and 13C nuclear magnetic resonance. Myrcene (47.0%) was the main component of needle oil, followed by β-pinene (28.4%) and α-pinene (12.5%). Branch oil also contained myrcene (32.8%), α-pinene (17.9%), β-pinene (9.8%), and a high content of limonene (20.0%). Finally, cone oil displayed α-pinene (44.1%) beside myrcene (11.5%), β-pinene (8.1%), and limonene (5.8%).

Sign in / Sign up

Export Citation Format

Share Document