Membrane filtration of kraft lignin: Structural charactristics and antioxidant activity of the low-molecular-weight fraction

2018 ◽  
Vol 112 ◽  
pp. 200-209 ◽  
Author(s):  
Selda Aminzadeh ◽  
Maris Lauberts ◽  
Galina Dobele ◽  
Jevgenija Ponomarenko ◽  
Tuve Mattsson ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
Membrane Filtration ◽  
Weight Fraction ◽  
Kraft Lignin ◽  
Low Molecular Weight

scholarly journals Endogenous Plasma Peptide Detection and Identification in the Rat by a Combination of Fractionation Methods and Mass Spectrometry

2007 ◽  
Vol 2 ◽  
pp. 117727190700200
Author(s):  
Fabrice Bertile ◽  
Flavie Robert ◽  
Véronique Delval-Dubois ◽  
Sarah Sanglier ◽  
Christine Schaeffer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Membrane Filtration ◽  
Solid Phase ◽  
Weight Fraction ◽  
Peptide Sequence ◽  
Low Molecular Weight ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

Mass spectrometry-based analyses are essential tools in the field of biomarker research. However, detection and characterization of plasma low abundance and/or low molecular weight peptides is challenged by the presence of highly abundant proteins, salts and lipids. Numerous strategies have already been tested to reduce the complexity of plasma samples. The aim of this study was to enrich the low molecular weight fraction of rat plasma. To this end, we developed and compared simple protocols based on membrane filtration, solid phase extraction, and a combination of both. As assessed by UV absorbance, an albumin depletion >99% was obtained. The multistep fractionation strategy (including reverse phase HPLC) allowed detection, in a reproducible manner (CV < 30%-35%), of more than 450 peaks below 3000 Da by MALDI-TOF/MS. A MALDI-TOF/MS-determined LOD as low as 1 fmol/μL was obtained, thus allowing nanoLC-Chip/MS/MS identification of spiked peptides representing ~10–6% of total proteins, by weight. Signal peptide recovery ranged between 5%-100% according to the spiked peptide considered. Tens of peptide sequence tags from endogenous plasma peptides were also obtained and high confidence identifications of low abundance fibrinopeptide A and B are reported here to show the efficiency of the protocol. It is concluded that the fractionation protocol presented would be of particular interest for future differential (high throughput) analyses of the plasma low molecular weight fraction.

In Vivo Studies on the Inhibition of Coagulation by Fractionated Heparin and by a Heparin Analogue I. Effects of Heparin Fractions

1981 ◽  
Vol 46 (03) ◽  
pp. 612-616 ◽  
Author(s):  
U Schmitz-Huebner ◽  
L Balleisen ◽  
F Asbeck ◽  
J van de Loo
Keyword(s):  
Molecular Weight ◽  
Day Treatment ◽  
Gel Filtration ◽  
Weight Fraction ◽  
In Vivo Studies ◽  
Low Molecular Weight ◽  
High Molecular Weight Fraction ◽  
Platelet Factor ◽  
Heparin Fractions

SummaryHigh and low molecular weight heparin fractions obtained by gel filtration chromatography of sodium mucosal heparin were injected subcutaneously into six healthy volunteers and compared with the unfractionated substance in a cross-over trial. Equal doses of 5,000 U were administered twice daily over a period of three days and heparin activity was repeatedly controlled before and 2, 4, 8 hrs after injection by means of the APTT, the anti-Xa clotting test and a chromogenic substrate assay. In addition, the in vivo effect of subcutaneously administered fractionated heparin on platelet function was examined on three of the volunteers. The results show that s.c. injections of the low molecular weight fraction induced markedly higher anti-Xa activity than injections of the other preparations. At the same time, APTT results did not significantly differ. Unfractionated heparin and the high molecular weight fraction enhanced ADP-induced platelet aggregation and collagen-mediated MDA production, while the low molecular weight fraction hardly affected these assays, but potently inhibited thrombin-induced MDA production. All heparin preparations stimulated the release of platelet Factor 4 in plasma. During the three-day treatment periods, no side-effects and no significant changes in the response to heparin injections were detected.

scholarly journals Investigating Lignin-Derived Monomers and Oligomers in Low-Molecular-Weight Fractions Separated from Depolymerized Black Liquor Retentate by Membrane Filtration

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2887
Author(s):  
Kena Li ◽  
Jens Prothmann ◽  
Margareta Sandahl ◽  
Sara Blomberg ◽  
Charlotta Turner ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Membrane Filtration ◽  
Black Liquor ◽  
Complex Mixture ◽  
Value Added ◽  
Kraft Pulping ◽  
Classification Model ◽  
Low Molecular Weight ◽  
Chemical Complexity

Base-catalyzed depolymerization of black liquor retentate (BLR) from the kraft pulping process, followed by ultrafiltration, has been suggested as a means of obtaining low-molecular-weight (LMW) compounds. The chemical complexity of BLR, which consists of a mixture of softwood and hardwood lignin that has undergone several kinds of treatment, leads to a complex mixture of LMW compounds, making the separation of components for the formation of value-added chemicals more difficult. Identifying the phenolic compounds in the LMW fractions obtained under different depolymerization conditions is essential for the upgrading process. In this study, a state-of-the-art nontargeted analysis method using ultra-high-performance supercritical fluid chromatography coupled to high-resolution multiple-stage tandem mass spectrometry (UHPSFC/HRMSn) combined with a Kendrick mass defect-based classification model was applied to analyze the monomers and oligomers in the LMW fractions separated from BLR samples depolymerized at 170–210 °C. The most common phenolic compound types were dimers, followed by monomers. A second round of depolymerization yielded low amounts of monomers and dimers, while a high number of trimers were formed, thought to be the result of repolymerization.

scholarly journals Candidate markers for the detection of hepatocellular carcinoma in low-molecular weight fraction of serum

2007 ◽  
Vol 28 (10) ◽  
pp. 2149-2153 ◽  
Author(s):  
Radoslav Goldman ◽  
Habtom W. Ressom ◽  
Mohamed Abdel-Hamid ◽  
Lenka Goldman ◽  
Antai Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Molecular Weight ◽  
Weight Fraction ◽  
Low Molecular Weight

Anti-Inflammatory Activity in the Low Molecular Weight Fraction of Commercial Human Serum Albumin (LMWF5A)

2015 ◽  
Vol 37 (1) ◽  
pp. 55-67 ◽  
Author(s):  
Gregory W. Thomas ◽  
Leonard T. Rael ◽  
Charles W. Mains ◽  
Denetta Slone ◽  
Matthew M. Carrick ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Weight Fraction ◽  
Inflammatory Activity ◽  
Low Molecular Weight ◽  
Anti Inflammatory

Characterization of Sol and Gel in Hevea Natural Rubber

1997 ◽  
Vol 70 (5) ◽  
pp. 707-713 ◽  
Author(s):  
Jitladda Tangpakdee ◽  
Yasukuki Tanaka
Keyword(s):  
Molecular Weight ◽  
Weight Fraction ◽  
Toluene Solution ◽  
Low Molecular Weight ◽  
Branch Points ◽  
Gel Content ◽  
High Ammonia ◽  
Linear Molecules ◽  
Cis And Trans

Abstract The gel content of rubber from high-ammonia latex (HA-latex) decreased significantly after deproteinization with proteolytic enzyme. The addition of 1–2% ethanol in toluene solution reduced the gel content of rubbers from HA-latex, deproteinized HA-latex (HA-DP) and pale crepe. Transesterification of the rubber in toluene solution with sodium methoxide dissolved the gel fraction. The gel fractions solubilized after transesterification showed molecular weight distribution rich in low molecular-weight fraction. The Huggins k′ constant of the fractionated rubbers from solubilized-gels was in the range of 0.42–0.45, lower than that of the fractionated HA-DP of 0.5–0.8. This indicates that all the branch-points were decomposed by transesterification to form linear molecules. The Mn values of rubber chains assembling the gel was 5.5−8.3×105 by 13C-NMR measurements of the ratio between cis- and trans-isoprene units, which were comparable to the molecular weight between crosslinks, Mc, of 7−11×105 by swelling measurements. These findings suggest that the branching and crosslinks are composed of two types of branch-points, i. e. one by association or aggregation of proteins or oligopeptides at the initiating end and the other by ester linkages including phosphoric ester at the terminal end.

scholarly journals Antitumor Activities of Low Molecular Weight Fraction Derived from the Cultured Fruit Body of Sparassis crispa in Tumor-Bearing Mice

2007 ◽  
Vol 54 (9) ◽  
pp. 419-423 ◽  
Author(s):  
Kyosuke Yamamoto ◽  
Yoshihiro Nishikawa ◽  
Takashi Kimura ◽  
Munehiko Dombo ◽  
Nariaki Matsuura ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Fruit Body ◽  
Weight Fraction ◽  
Low Molecular Weight ◽  
Antitumor Activities ◽  
Tumor Bearing ◽  
Sparassis Crispa
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