Molecular Weight Measurements of Low Molecular Weight Heparins by Gel Permeation Chromatography

1997 ◽  
Vol 77 (04) ◽  
pp. 668-674 ◽  
Author(s):  
B Mulloy ◽  
C Gee ◽  
S F Wheeler ◽  
R Wait ◽  
E Gray ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
High Performance ◽  
Gel Permeation Chromatography ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Molecular Weights ◽  
Calibration Table ◽  
Gel Permeation ◽  
Degraded Material

SummaryThe molecular weight profiles of low molecular weight heparin samples have been measured by high-performance gel permeation chromatography using as calibrant the heparinase-degraded material (90/686) now established as the 1st International Reference Preparation (IRP) Low Molecular Weight Heparin for Molecular Weight Calibration. Use of the calibrant as a broad molecular weight standard is described and a calibration table provided based on data collected over several years in one laboratory.In order to confirm the assignment of degree of polymerisation to resolved oligosaccharide peaks in the calibrant, molecular weights of oligosaccharides fractionated from the 1st IRP were independently determined by fast atom bombardment mass spectrometry (FAB MS).The molecular weight distributions of commercial low molecular weight heparins have been characterized. Measurements of molecular weight parameters of heparin molecular weight standards from several sources provide comparisons between the molecular weight scales of this and other studies.

scholarly journals Fractionation of lignosulphonates released during the early stages of delignification

1983 ◽  
Vol 61 (2) ◽  
pp. 416-420 ◽  
Author(s):  
Norman G. Lewis ◽  
David A. I. Goring ◽  
Alfred Wong
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Black Spruce ◽  
Gel Permeation Chromatography ◽  
Bimodal Distribution ◽  
High Yield ◽  
Low Molecular Weight ◽  
Lower Yield ◽  
Spruce Wood ◽  
Gel Permeation

High-yield spent bisulphite liquor (HY-SBL) from sulphonated black spruce wood (Piceamariana) was fractionated by gel permeation chromatography (GPC) and by high-performance liquid chromatography (HPLC). The GPC fractionation gave a wide bimodal distribution, whereas with HPLC, a more detailed resolution was seen with the bulk of the fraction giving several clearly defined peaks. The paucidisperse material was further concentrated by a bulk fractionation of the crude SBL which included complexing the lignosulphonates with dicyclohexylamine. The isolated paucidisperse material was found to be dialyzable and to constitute 90% of the lignosulphonate in the sample of SBL. If the bisulphite pulp obtained was recooked in fresh acid sulphite liquor to a lower yield, most of the lignosulphonate dissolved was widely polydisperse with no indication of the discrete components resolvable by HPLC. However, 25% of the lignin made soluble was in the form of the paucidisperse fractions. In all, we were able to obtain about 50% of the lignin in spruce wood as a relatively low molecular weight lignosulphonate resolvable into discrete fractions by HPLC.

Comparison of Number—Average Molecular Weights Calculated by GPC and Membrane Osmometry

1973 ◽  
Vol 46 (1) ◽  
pp. 115-126
Author(s):  
M. R. Ambler ◽  
R. D. Mate
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Appreciable Amount ◽  
Diffusion Limit ◽  
Low Molecular Weight ◽  
Molecular Weights ◽  
True Value ◽  
Usual Manner ◽  
Gel Permeation ◽  
Polymer Species

Abstract Data are presented which show that when a polymer contains an appreciable amount of low molecular weight species below the diffusion limit of the osmometer membrane, the osmotic molecular weight, Mn, is generally higher than the Mn calculated from gel-permeation chromatography (GPC). Experiments were performed on samples of poly(vinylchloride) (PVC) and high-cis poly (butadiene) polymers. Osmotic data were obtained in the usual manner, while GPC data were obtained using the universal calibration approach. It was found that when all polymer species below approximately 10,000 molecular weight were excluded from the calculation of Mn by GPC, agreement in Mn was obtained between membrane osmometry and GPC. The data obtained suggest that the choice of Mn as measured by membrane osmometry in the calibration of the GPC should not be done casually, as the measured Mn may not reflect the “true” value of that sample, especially when the polymer sample contains an appreciable amount of low molecular weight material.

Ultra-low-molecular-weight heparins: Precise structural features impacting specific anticoagulant activities

2013 ◽  
Vol 109 (03) ◽  
pp. 471-478 ◽  
Author(s):  
Marcelo Lima ◽  
Christian Viskov ◽  
Frederic Herman ◽  
Angel Gray ◽  
Eduardo de Farias ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Structural Data ◽  
Monosaccharide Composition ◽  
Structural Features ◽  
Therapeutic Agents ◽  
Resonance Spectroscopy ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Molecular Weights

SummaryUltra-low-molecular-weight heparins (ULMWHs) with better efficacy and safety ratios are under development; however, there are few structural data available. The main structural features and molecular weight of ULMWHs were studied and compared to enoxaparin. Their monosaccharide composition and average molecular weights were determined and preparations studied by nuclear magnetic resonance spectroscopy, scanning ultraviolet spectroscopy, circular dichroism and gel permeation chromatography. In general, ULMWHs presented higher 3-O-sulphated glucosamine and unsaturated uronic acid residues, the latter being comparable with their higher degree of depolymerisation. The analysis showed that ULMWHs are structurally related to LMWHs; however, their monosaccharide/oligosaccharide compositions and average molecular weights differed considerably explaining their different anticoagulant activities. The results relate structural features to activity, assisting the development of new and improved therapeutic agents, based on depolymerised heparin, for the prophylaxis and treatment of thrombotic disorders.

Pharmacokinetics of Subcutaneous Low Molecular Weight Heparin (Enoxaparin) in Dogs

2009 ◽  
Vol 45 (6) ◽  
pp. 261-267 ◽  
Author(s):  
Kari V. Lunsford ◽  
Andrew J. Mackin ◽  
V. Cory Langston ◽  
Marjory Brooks
Keyword(s):  
Molecular Weight ◽  
Veterinary Medicine ◽  
Low Molecular Weight Heparin ◽  
Patient Monitoring ◽  
Target Range ◽  
Low Molecular Weight ◽  
Close Monitoring ◽  
Low Molecular Weight Heparins ◽  
Pharmacodynamic Profile ◽  
Hemorrhagic Complications

Unfractionated heparin has been the standard heparin used in human and veterinary medicine for its anticoagulation effect; however, it has a complex pharmacodynamic profile that requires close monitoring. Low molecular weight heparins have a more predictable bioavailability, allowing standardized dosing without individual patient monitoring. This project was designed to a) evaluate the pharmacokinetics of the subcutaneous (SC) administration of the low molecular weight heparin, enoxaparin, in dogs using anti-Xa activity as a marker of plasma enoxaparin concentrations and b) to establish the dose necessary to maintain activity within an established target range. Enoxaparin at 0.8 mg/kg SC q 6 hours consistently maintained target levels of anti-Xa activity in normal dogs without evidence of hemorrhagic complications.

scholarly journals Modern low-molecular-weight heparins in the prevention and treatment of venous thromboembolic complications in oncourologic patients

2018 ◽  
pp. 106-112
Author(s):  
N. V. Vorobyev ◽  
S. V. Popov
Keyword(s):  
Molecular Weight ◽  
Impaired Renal Function ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Efficacy And Safety ◽  
Thromboembolic Complications ◽  
Antithrombotic Effect ◽  
Low Molecular Weight Heparins ◽  
Prevention And Treatment ◽  
Venous Thromboembolic

Oncourologic diseases are accompanied by a risk for subsequent venous thromboembolic complications, which are rated the most dangerous in terms of thrombogenic effect. The article presents a review of the clinical studies of efficacy and safety, and the experience in using of modern low-molecular-weight heparins in clinical practice - drugs of choice for the prevention of venous thromboembolic complications in cancer patients. Particular attention is paid to Bemiparin - a new second-generation low-molecular-weight heparin with a significant antithrombotic effect and improved pharmacological parameters that allow it to be successfully used in patients with impaired renal function in oncourological practice.

Comparison of exopolysaccharides from mucoid and nonmucoid strains of Clavibacter michiganensis subspecies sepedonicus

1993 ◽  
Vol 39 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Paul J. Henningson ◽  
Neil C. Gudmestad
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Size Exclusion ◽  
Enzyme Linked Immunosorbent Assay ◽  
Low Molecular Weight ◽  
Neutral Sugar ◽  
Clavibacter Michiganensis ◽  
Serological Reaction ◽  
Molecular Weights ◽  
Exclusion Chromatography

The exopolysaccharides produced by six strains of Clavibacter michiganensis ssp. sepedonicus were isolated and purified by liquid chromatography. Neutral sugar composition and molecular weights were determined for each polysaccharide fraction, using gas chromatography and high-performance size-exclusion chromatography. The serological reaction of each fraction was tested using enzyme-linked immunosorbent assay. Exopolysaccharide from nonmucoid strains contained only low molecular weight polysaccharides (1.5 × 103 to 1.1 × 104). Exopolysaccharide from mucoid and intermediate strains could be separated into low (4.0 × 103 to 1.1 × 104) molecular weight and high (5.0 × 105 to 1.6 × 106) molecular weight fractions. High molecular weight polysaccharides were composed almost exclusively of galactose, glucose, and fucose. The ratios of these sugars were highly variable among strains. Low molecular weight polysaccharides were primarily composed of galactose with significant and varying amounts of glucose, rhamnose, mannose, and ribose. All polysaccharide fractions except one, produced by a nonmucoid strain, reacted in the immunoassay test.Key words: exopolysaccharide, polysaccharide, Clavibacter, michiganensis, sepedonicus.

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