scholarly journals SULFATED DERIVATIVES OF ARABINOGALACTAN AND THEIR ANTICOAGULANT ACTIVITY

2019 ◽  
pp. 47-56
Author(s):  
Svetlana Alekseyevna Kuznetsova ◽  
Natal'ya Yur'yevna Vasilyeva ◽  
Natal'ya Nikolayevna Drozd ◽  
Mikhail Aleksandrovich Mikhailenko ◽  
Tat'yana Petrovna Shakhtshneider ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Sulfur Content ◽  
Anticoagulant Activity ◽  
Factor Xa ◽  
Sulfamic Acid ◽  
In Vitro Study ◽  
Acid Complex ◽  
Derivatives Of ◽  
Salt Forms

The IR spectra and molecular mass distribution of arabinogalactan sulfates in the form of sodium and ammonium salts, obtained using various sulfating reagents, were compared. According to the obtained data, the sulfated derivatives of arabinogalactan differ from each other by the nature of the hydrogen bonds and the molecular weight distribution. Using coagulological tests at the activation of coagulation of platelet-poor human plasma, in vitro study of the anticoagulant properties of arabinogalactan sulfated derivatives in various salt forms differing in methods of  preparation, degree of sulfation and molecular weight was conducted. It was established that the sample in the form of arabinogalactan sodium salt (SAG 1) with a sulfur content of 13.2 wt.% аnd a polydispersity degree of 1.52 showed 2 times more anticoagulant activity than the sample in the form of ammonium salt of arabinogalactan (SAG 2) with the sulfur content of 6.6 wt.% and the degree of polydispersity of 1.30. Antithrombin (aIIa) activity of samples obtained by sulfation with pyridine and sulfuric anhydride complex (SAG 1) and sulfamic acid complex (SAG 2) was, respectively, 23.42±1.86 and 10.20±1.50 U/mg; the anti-factor Xa activity of SAG 1 and SAG 2 was 2.13±0.42 and 0.37±0.08 U/mg; and the ratio aIIa/aXa for SAG1 and SAG 2 was 11 and 28, respectively. The less activity of antifactor Xa(aXA) of SAG as compared to unfractionated heparin (UFG) and higher rations of activities aIIa/aXa may contribute the less provocation of bleeding by SAG samples in the comparition with UFG.

scholarly journals Synthesis, Docking, and In Vitro Anticoagulant Activity Assay of Hybrid Derivatives of Pyrrolo[3,2,1-ij]Quinolin-2(1H)-one as New Inhibitors of Factor Xa and Factor XIa

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1889 ◽  
Author(s):  
Nadezhda Novichikhina ◽  
Ivan Ilin ◽  
Anna Tashchilova ◽  
Alexey Sulimov ◽  
Danil Kutov ◽  
...  
Keyword(s):  
Anticoagulant Activity ◽  
Factor Xa ◽  
Coagulation Factor ◽  
Coagulation Factors ◽  
Protein Targets ◽  
Ic50 Value ◽  
Anticoagulant Drugs ◽  
Factor Xia ◽  
Derivatives Of

Coagulation factor Xa and factor XIa are proven to be convenient and crucial protein targets for treatment for thrombotic disorders and thereby their inhibitors can serve as effective anticoagulant drugs. In the present work, we focused on the structure–activity relationships of derivatives of pyrrolo[3,2,1-ij]quinolin-2(1H)-one and an evaluation of their activity against factor Xa and factor XIa. For this, docking-guided synthesis of nine compounds based on pyrrolo[3,2,1-ij]quinolin-2(1H)-one was carried out. For the synthesis of new hybrid hydropyrrolo[3,2,1-ij]quinolin-2(1H)-one derivatives, we used convenient structural modification of both the tetrahydro- and dihydroquinoline moiety by varying the substituents at the C6,8,9 positions. In vitro testing revealed that four derivatives were able to inhibit both coagulation factors and three compounds were selective factor XIa inhibitors. An IC50 value of 3.68 μM for was found for the best factor Xa inhibitor and 2 μM for the best factor XIa inhibitor.

scholarly journals Influence of molecular weight of chemically sulfated citrus pectin fractions on their antithrombotic and bleeding effects

2009 ◽  
Vol 101 (05) ◽  
pp. 860-866 ◽  
Author(s):  
Thales Cipriani ◽  
Ana Helena Gracher ◽  
Lauro de Souza ◽  
Roberto Fonseca ◽  
Celso Belmiro ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Venous Thrombosis ◽  
Anticoagulant Activity ◽  
Factor Xa ◽  
Sulfated Polysaccharides ◽  
Antithrombotic Agent ◽  
Total Inhibition ◽  
Almost All

SummaryEvaluated were the anticoagulant and antithrombotic activities, and bleeding effect of two chemically sulfated polysaccharides, obtained from citric pectin, with different average molar masses. Both low-molecular-weight (Pec-LWS, 3,600 g/mol) and high-molecular-weight sulfated pectins (Pec-HWS, 12,000 g/mol) had essentially the same structure, consisting of a (1→4)-linked α-D-GalpA chain with almost all its HO-2 and HO-3 groups substituted by sulfate. Both polysaccharides had anticoagulant activity in vitro, although Pec-HWS was a more potent anti-thrombotic agent in vivo, giving rise to total inhibition of venous thrombosis at a dose of 3.5 mg/kg body weight. Surprisingly, in contrast with heparin, Pec-HWS and Pec-LWS are able to directly inhibit α-thrombin and factor Xa by a mechanism independent of antithrombin (AT) and/or heparin co-factor II (HCII). Moreover, Pec-HWS provided a lower risk of bleeding than heparin at a dose of 100% effectiveness against venous thrombosis, indicating it to be a promising antithrombotic agent.

Low Molecular Weight Heparin Is Responsible for the Anti-Xa Activity of Desmin 370

1996 ◽  
Vol 75 (02) ◽  
pp. 286-291 ◽  
Author(s):  
David Brieger ◽  
Joan Dawes
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Anticoagulant Activity ◽  
Factor Xa ◽  
Biologically Active ◽  
Low Molecular Weight ◽  
Dermatan Sulphate ◽  
Molecular Weight Range ◽  
Sulphated Glycosaminoglycan

SummaryDermatan sulphate does not catalyse the inactivation of factor Xa. However, the low molecular weight (LMW) dermatan sulphate Desmin 370 has been shown to generate circulating anti-Xa activity following administration to humans. Using a single batch of Desmin 370, we measured 3 U/mg of anti-Xa activity by amidolytic assay in vitro. The material responsible for this activity had a lower molecular weight range (6000 and 1800 Da) than Desmin 370 and was more highly sulphated than the bulk of the drug. Heparinase digestion of Desmin 370 eliminated 90% of the in vitro anti-Xa activity without significantly interfering with its ability to potentiate inactivation of thrombin by HCII, suggesting that the anti-Xa activity is not due to dermatan sulphate and is probably heparin. When 125I-labelled Desmin 370 together with 40 mg/kg carrier drug was administered intravenously to a rabbit, anti-Xa activity was readily detectable in the plasma for up to 10 h and had a longer half-life than the sulphated radiolabel. Most of this anticoagulant activity was recovered from the plasma by Polybrene affinity chromatography and was probably a sulphated glycosaminoglycan. Administration of the heparinase-digested drug to a rabbit resulted in 70% less anti-Xa activity than the undigested drug. We conclude that Desmin 370 contains detectable quantities of biologically active low molecular weight heparin, which is responsible for persistent anti-Xa activity following intravenous administration.

Dermatan Sulfate and LMW Heparin Enhance the Anticoagulant Action of Activated Protein C

1999 ◽  
Vol 82 (11) ◽  
pp. 1462-1468 ◽  
Author(s):  
José Fernández ◽  
Jari Petäjä ◽  
John Griffin
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Protein C ◽  
Dermatan Sulfate ◽  
Anticoagulant Activity ◽  
Activated Protein C ◽  
Factor V ◽  
Factor Va ◽  
Anticoagulant Action

SummaryUnfractionated heparin potentiates the anticoagulant action of activated protein C (APC) through several mechanisms, including the recently described enhancement of proteolytic inactivation of factor V. Possible anticoagulant synergism between APC and physiologic glycosaminoglycans, pharmacologic low molecular weight heparins (LMWHs), and other heparin derivatives was studied. Dermatan sulfate showed potent APC-enhancing effect. Commercial LMWHs showed differing abilities to promote APC activity, and the molecular weight of LMWHs correlated with enhancement of APC activity. Degree of sulfation of the glycosaminoglycans influenced APC enhancement. However, because dextran sulfates did not potentiate APC action, the presence of sulfate groups per se on a polysaccharide is not sufficient for APC enhancement. As previously for unfractionated heparin, APC anticoagulant activity was enhanced by glycosaminoglycans when factor V but not factor Va was the substrate. Thus, dermatan sulfate and LMWHs exhibit APC enhancing activity in vitro that could be of physiologic and pharmacologic significance.

Assays for Phospholipid-Dependent Formation of Thrombin and Xa: A Potential Method for Quantifying Lupus Anticoagulant Activity

1991 ◽  
Vol 66 (04) ◽  
pp. 453-458 ◽  
Author(s):  
John T Brandt
Keyword(s):  
Specific Activity ◽  
Anticoagulant Activity ◽  
Factor Xa ◽  
Clinical Importance ◽  
Potential Method ◽  
Quantitative Expression ◽  
Increased Risk ◽  
Apparent Association

SummaryLupus anticoagulants (LAs) are antibodies which interfere with phospholipid-dependent procoagulant reactions. Their clinical importance is due to their apparent association with an increased risk of thrombo-embolic disease. To date there have been few assays for quantifying the specific activity of these antibodies in vitro and this has hampered attempts to purify and characterize these antibodies. Methods for determining phospholipid-dependent generation of thrombin and factor Xa are described. Isolated IgG fractions from 7 of 9 patients with LAs were found to reproducibly inhibit enzyme generation in these assay systems, permitting quantitative expression of inhibitor activity. Different patterns of inhibitory activity, based on the relative inhibition of thrombin and factor Xa generation, were found, further substantiating the known heterogeneity of these antibodies. These systems may prove helpful in further purification and characterization of LAs.

The Anticoagulant Properties of a Modified Form of Protein S

1988 ◽  
Vol 60 (02) ◽  
pp. 298-304 ◽  
Author(s):  
C A Mitchell ◽  
S M Kelemen ◽  
H H Salem
Keyword(s):  
Monoclonal Antibody ◽  
Anticoagulant Activity ◽  
Activated Protein C ◽  
Factor Xa ◽  
Protein S ◽  
Human Neutrophil Elastase ◽  
Factor X ◽  
Sds Page

SummaryProtein S (PS) is a vitamin K-dependent anticoagulant that acts as a cofactor to activated protein C (APC). To date PS has not been shown to possess anticoagulant activity in the absence of APC.In this study, we have developed monoclonal antibody to protein S and used to purify the protein to homogeneity from plasma. Affinity purified protein S (PSM), although identical to the conventionally purified protein as judged by SDS-PAGE, had significant anticoagulant activity in the absence of APC when measured in a factor Xa recalcification time. Using SDS-PAGE we have demonstrated that prothrombin cleavage by factor X awas inhibited in the presence of PSM. Kinetic analysis of the reaction revealed that PSM competitively inhibited factor X amediated cleavage of prothrombin. PS preincubated with the monoclonal antibody, acquired similar anticoagulant properties. These results suggest that the interaction of the monoclonal antibody with PS results in an alteration in the protein exposing sites that mediate the observed anticoagulant effect. Support that the protein was altered was derived from the observation that PSM was eight fold more sensitive to cleavage by thrombin and human neutrophil elastase than conventionally purified protein S.These observations suggest that PS can be modified in vitro to a protein with APC-independent anticoagulant activity and raise the possibility that a similar alteration could occur in vivo through the binding protein S to a cellular or plasma protein.

Comparison of the Non-Specific Binding of Unfractionated Heparin and Low Molecular Weight Heparin (Enoxaparin) to Plasma Proteins

1993 ◽  
Vol 70 (04) ◽  
pp. 625-630 ◽  
Author(s):  
Edward Young ◽  
Benilde Cosmi ◽  
Jeffrey Weitz ◽  
Jack Hirsh
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Plasma Proteins ◽  
Low Molecular Weight Heparin ◽  
Specific Binding ◽  
Anticoagulant Activity ◽  
Factor Xa ◽  
Low Molecular Weight ◽  
Heparin Binding ◽  
Fixed Amount

SummaryThe non-specific binding of anticoagulantly-active heparin to plasma proteins may influence its anticoagulant effect. We used low affinity heparin (LAH) essentially devoid of anti-factor Xa activity to investigate the extent and possible mechanism of this non-specific binding. The addition of excess LAH to platelet-poor plasma containing a fixed amount of unfractionated heparin doubled the anti-factor Xa activity presumably because it displaces anticoagulantly-active heparin from plasma proteins. Although dextran sulfates of varying molecular weights also increased the anti-factor Xa activity, less sulfated heparin-like polysaccharides had no effect. These findings suggest that the ability to displace active heparin from plasma protein binding sites is related to charge and may be independent of molecular size. In contrast to its effect in plasma containing unfractionated heparin, there was little augmentation in anti-factor Xa activity when LAH was added to plasma containing low molecular weight heparin (LMWH), indicating that LMWH binds less to plasma proteins than unfractionated heparin. This concept is supported by studies comparing the anticoagulant activity of unfractionated heparin and LMWH in plasma with that in buffer containing antithrombin III. The anti-factor Xa activity of unfractionated heparin was 2-fold less in plasma than in the purified system. In contrast, LMWH had identical anti-factor Xa activity in both plasma and buffer, respectively. These findings may be clinically relevant because the recovered anti-factor Xa activity of unfractionated heparin was 33% lower in plasma from patients with suspected venous thrombosis than in plasma from healthy volunteers. The reduced heparin recovery in patient plasma reflects increased heparin binding to plasma proteins because the addition of LAH augmented the anti-factor Xa activity. In contrast to unfractionated heparin, there was complete recovery of LMWH added to patient plasma and little increase of anti-factor Xa activity after the addition of LAH. These findings may explain why LMWH gives a more predictable dose response than unfractionated heparin.

Effects of Two Different Doses of Hirudin on APTT, Determined with Eight Different Reagents

1995 ◽  
Vol 73 (02) ◽  
pp. 219-222 ◽  
Author(s):  
Manuel Monreal ◽  
Luis Monreal ◽  
Rafael Ruiz de Gopegui ◽  
Yvonne Espada ◽  
Ana Maria Angles ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Anticoagulant Activity ◽  
Subcutaneous Administration ◽  
In Vitro Study ◽  
Ex Vivo Model ◽  
Suitable Candidate ◽  
Significant Prolongation ◽  
High Doses ◽  
Different Doses

SummaryThe APTT has been considered the most suitable candidate to monitor the anticoagulant activity of hirudin. However, its use is hampered by problems of standardization, which make the results heavily dependent on the responsiveness of the reagent used. Our aim was to investigate if this different responsiveness of different reagents when added in vitro is to be confirmed in an ex vivo study.Two different doses of r-hirudin (CGP 39393), 0.3 mg/kg and 1 mg/kg, were administered subcutaneously to 20 New Zealand male rabbits, and the differences in prolongation of APTT 2 and 12 h later were compared, using 8 widely used commercial reagents. All groups exhibited a significant prolongation of APTT 2 h after sc administration of hirudin, both at low and high doses. But this prolongation persisted 12 h later only when the PTTa reagent (Boehringer Mannheim) was used. In general, hirudin prolonged the APTT most with the silica- based reagents.In a further study, we compared the same APTT reagents in an in vitro study in which normal pooled plasma was mixed with increasing amount of hirudin. We failed to confirm a higher sensitivity for silica- containing reagents. Thus, we conclude that subcutaneous administration of hirudin prolongs the APTT most with the silica-based reagents, but this effect is exclusive for the ex vivo model.

Toxicity of Heparinoids, with Special Reference to the Precipitation of Fibrinogen

1964 ◽  
Vol 12 (01) ◽  
pp. 232-261 ◽  
Author(s):  
S Sasaki ◽  
T Takemoto ◽  
S Oka
Keyword(s):  
Molecular Weight ◽  
Dextran Sulfate ◽  
Anticoagulant Activity ◽  
Molecular Structures ◽  
Severe Reaction ◽  
Clinical Use ◽  
Molecular Weights ◽  
Close Relationship

SummaryTo demonstrate whether the intravascular precipitation of fibrinogen is responsible for the toxicity of heparinoid, the relation between the toxicity of heparinoid in vivo and the precipitation of fibrinogen in vitro was investigated, using dextran sulfate of various molecular weights and various heparinoids.1. There are close relationships between the molecular weight of dextran sulfate, its toxicity, and the quantity of fibrinogen precipitated.2. The close relationship between the toxicity and the precipitation of fibrinogen found for dextran sulfate holds good for other heparinoids regardless of their molecular structures.3. Histological findings suggest strongly that the pathological changes produced with dextran sulfate are caused primarily by the intravascular precipitates with occlusion of the capillaries.From these facts, it is concluded that the precipitates of fibrinogen with heparinoid may be the cause or at least the major cause of the toxicity of heparinoid.4. The most suitable molecular weight of dextran sulfate for clinical use was found to be 5,300 ~ 6,700, from the maximum value of the product (LD50 · Anticoagulant activity). This product (LD50 · Anticoagulant activity) can be employed generally to assess the comparative merits of various heparinoids.5. Clinical use of the dextran sulfate prepared on this basis gave satisfactory results. No severe reaction was observed. However, two delayed reactions, alopecia and thrombocytopenia, were observed. These two reactions seem to come from the cause other than intravascular precipitation.

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