The Development of New Low-Molecular-Weight Factor Xa Inhibitors That Are Potential Anticoagulants

Author(s):  
Dmitry G. Tovbin ◽  
Dmitry N. Tarasov ◽  
Dmitry V. Malakhov ◽  
Natalia A. Tserkovnikova ◽  
Arseniy V. Aybush ◽  
...  

Background: Despite the introduction of direct oral anticoagulants, the search for new oral anticoagulants remains an urgent task. Objective: Using the docking and scoring, based on physical methods, simple chemical rules, methods of synthesis and activity measurement, to develop new low-molecular-weight inhibitors of factor Xa, which are potential anticoagulants. Method: The development of leads was based on chemical synthesis and the structure-based drug design methods. The basic idea is to combine the two approaches: one based on predictive modeling, and the other – on the experimental data. Results: In frame of our concept we developed some nanomolar leads. Further chemical modification improved the inhibition constant by more than one order. Discussion: The method proposed in this paper, as well as other methods, includes virtual screening, screening, chemical synthesis and activity measurement. However, the most time – consuming process in this method (chemical synthesis) was decided to simplify and reduce the cost to the extent that it could be allowed: a very simple chemical reaction was chosen - the formation of an amide bond. Conclusion: In this work, we demonstrated how, using simple chemical rules, based on the structure-based drug design, substances with a nanomolar concentration of activity can be developed. Using our method, we developed substances with nanomolar concentration of activity. Further chemical modification of this leads improved the inhibition constant by more than one order.

2011 ◽  
Vol 10 (4) ◽  
pp. 101-106 ◽  
Author(s):  
O. V. Averkov ◽  
I. V. Shevchenko ◽  
T. Sh. Mirilashvili ◽  
Zh. D. Kobalava

This review is focussed on the problem of venous thromboembolism in patients with heart failure (HF). The results of the major clinical trials of antithrombotic therapy in HF patients are presented. The authors discuss comparative effectiveness, safety, and tolerability of unfractionated heparins, low molecular weight heparins, and fondaparinux. The results of the two trials, MAGELLAN and ADOPT, are expected to clarify the clinical potential of such oral anticoagulants as rivaroxaban and apixaban (Factor Xa inhibitors). The problem of low rates e of preventive antithrombotic administration is emphasized.


1993 ◽  
Vol 70 (06) ◽  
pp. 0909-0914 ◽  
Author(s):  

SummaryFibrin D-Dimer (D-Di), prothrombin activation fragment (F 1+2) and thrombin-antithrombin III complexes (TAT) were measured using ELISA procedures in the plasma of patients with an acute deep venous thrombosis (DVT), at presentation and on days 2, 6 and 10 after initiation of heparin treatment. Patients were randomly allocated into two treatment groups: 44 patients received adapted doses of continuous intravenous unfractionated heparin (UH) whereas 47 received 1 mg/kg every twelve hours of a low molecular weight heparin (enoxaparin) subcutaneously. A phlebography and a perfusion lung scan were performed before inclusion and on day 10. Failure of therapy (n = 9) was defined by venogram worsening or confirmed pulmonary embolism. Improvement (n = 44) or stationary state (n = 38) were defined by venogram evolution in the absence of new leg scan defects.At presentation, D-Di, F 1 + 2 and TAT were above cut-off values in 97, 66 and 89% of patients respectively. D-Di levels correlated with the extent of venous thrombosis whereas TAT and F 1 + 2 did not. Mean levels of D-Di decreased sharply during the first days of treatment but were still abnormal on day 10. A secondary increase of D-Di on days 6 or 10 by more than 3 μg/ml occurred in 4 of the 9 patients who developed a thromboembolic recurrence but in none of the 72 patients who had a more favorable outcome. F 1 + 2 and TAT time-courses were not related to clinical evolution. In the Enoxaparin group, there was no relationship between antifactor Xa activities and any biological markers. TAT and F 1 + 2 levels fell on day 2 and remained stable until day 10. In contrast, in the UH group, TAT and F 1 + 2 did not significantly decrease on day 2, probably due to a delay in dose adaptation, but they declined slowly until day 10.In conclusion, D-Di displays a higher sensitivity than F 1 + 2 or TAT for the diagnosis of D\T. D-Di, but not TAT or F 1 + 2, follow-up seems to be of potential value for early detection of recurrency. Hemostatic activation is controlled earlier by fixed doses of a low molecular weight heparin, irrespective of the plasma anti-factor Xa activities, than by unfractionated heparin at adapted doses.


1993 ◽  
Vol 70 (04) ◽  
pp. 625-630 ◽  
Author(s):  
Edward Young ◽  
Benilde Cosmi ◽  
Jeffrey Weitz ◽  
Jack Hirsh

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.


1995 ◽  
Vol 74 (02) ◽  
pp. 660-666 ◽  
Author(s):  
P Mismetti ◽  
J Reynaud ◽  
B Tardy-Poncet ◽  
S Laporte-Simitsidis ◽  
M Scully ◽  
...  

SummaryLow molecular weight heparin (LMWH) is currently prescribed for the treatment of deep vein thrombosis at the dose of 100 IU antiXa/kg twice daily or at a dose of 175 IU antiXa/kg once daily with a similar efficacy. We decided to study the chrono-pharmacology of curative dose of LMWH once daily administrated according to the one previously described with unfractionated heparin (UFH).Ten healthy volunteers participated in an open three-period crossover study according to three 24 h cycles, separated by a wash-out interval lasting 7 days: one control cycle without injection, two cycles with subcutaneous injection of 200 IU antiXa/kg of Dalteparin (Fragmin®) at 8 a.m. or at 8 p.m. Parameters of heparin activity were analysed as maximal values and area under the curve.Activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT) and tissue factor pathway inhibitor (TFPI) were higher after 8 p.m. injection than after 8 a.m. injection (p <0.05) while no chrono-pharmacological variation of anti factor Xa (AXa) activity was observed. Thus the biological anticoagulant effect of 200 IU antiXa/kg of Dalteparin seems to be higher after an evening injection than after a morning injection.A chrono-therapeutic approach with LMWH, as prescribed once daily, deserves further investigation since our results suggest that a preferential injection time may optimise the clinical efficacy of these LMWH.


1997 ◽  
Vol 17 (03) ◽  
pp. 161-162
Author(s):  
Thomas Hyers

SummaryProblems with unfractionated heparin as an antithrombotic have led to the development of new therapeutic agents. Of these, low molecular weight heparin shows great promise and has led to out-patient therapy of DVT/PE in selected patients. Oral anticoagulants remain the choice for long-term therapy. More cost-effective ways to give oral anticoagulants are needed.


1983 ◽  
Vol 49 (02) ◽  
pp. 109-115 ◽  
Author(s):  
M Hoylaerts ◽  
E Holmer ◽  
M de Mol ◽  
D Collen

SummaryTwo high affinity heparin fragments (A/r 4,300 and M, 3,200) were covalently coupled to antithrombin III (J. Biol. Chem. 1982; 257: 3401-3408) with an apparent 1:1 stoichiometry and a 30-35% yield.The purified covalent complexes inhibited factor Xa with second order rate constants very similar to those obtained for antithrombin III saturated with these heparin fragments and to that obtained for the covalent complex between antithrombin III and native high affinity heparin.The disappearance rates from plasma in rabbits of both low molecular weight heparin fragments and their complexes could adequately be represented by two-compartment mammillary models. The plasma half-life (t'/j) of both low Afr-heparin fragments was approximately 2.4 hr. Covalent coupling of the fragments to antithrombin III increased this half-life about 3.5 fold (t1/2 ≃ 7.7 hr), approaching that of free antithrombin III (t1/2 ≃ 11 ± 0.4 hr) and resulting in a 30fold longer life time of factor Xa inhibitory activity in plasma as compared to that of free intact heparin (t1/2 ≃ 0.25 ± 0.04 hr).


2020 ◽  
Vol 26 (8) ◽  
pp. 802-814 ◽  
Author(s):  
Nemanja Turkovic ◽  
Branka Ivkovic ◽  
Jelena Kotur-Stevuljevic ◽  
Milica Tasic ◽  
Bojan Marković ◽  
...  

Background: Since the beginning of the HIV/AIDS epidemic, 75 million people have been infected with the HIV and about 32 million people have died of AIDS. Investigation of the molecular mechanisms critical to the HIV replication cycle led to the identification of potential drug targets for AIDS therapy. One of the most important discoveries is HIV-1 protease, an enzyme that plays an essential role in the replication cycle of HIV. Objective: The aim of the present study is to synthesize and investigate anti-HIV-1 protease activity of some chalcone derivatives with the hope of discovering new lead structure devoid drug resistance. Methods: 20 structurally similar chalcone derivatives were synthesized and their physico-chemical characterization was performed. Binding of chalcones to HIV-1 protease was investigated by fluorimetric assay. Molecular docking studies were conducted to understand the interactions. Results: The obtained results revealed that all compounds showed anti-HIV-1 protease activity. Compound C1 showed the highest inhibitory activity with an IC50 value of 0.001 μM, which is comparable with commercial product Darunavir. Conclusion: It is difficult to provide general principles of inhibitor design. Structural properties of the compounds are not the only consideration; ease of chemical synthesis, low molecular weight, bioavailability, and stability are also of crucial importance. Compared to commercial products the main advantage of compound C1 is the ease of chemical synthesis and low molecular weight. Furthermore, compound C1 has a structure that is different to peptidomimetics, which could contribute to its stability and bioavailability.


Blood ◽  
2004 ◽  
Vol 103 (4) ◽  
pp. 1356-1363 ◽  
Author(s):  
Barbara P. Schick ◽  
David Maslow ◽  
Adrianna Moshinski ◽  
James D. San Antonio

Abstract Patients given unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) for prophylaxis or treatment of thrombosis sometimes suffer serious bleeding. We showed previously that peptides containing 3 or more tandem repeats of heparin-binding consensus sequences have high affinity for LMWH and neutralize LMWH (enoxaparin) in vivo in rats and in vitro in citrate. We have now modified the (ARKKAAKA)n tandem repeat peptides by cyclization or by inclusion of hydrophobic tails or cysteines to promote multimerization. These peptides exhibit high-affinity binding to LMWH (dissociation constant [Kd], ≈ 50 nM), similar potencies in neutralizing anti–Factor Xa activity of UFH and enoxaparin added to normal plasma in vitro, and efficacy equivalent to or greater than protamine. Peptide (ARKKAAKA)3VLVLVLVL was most effective in all plasmas from enoxaparin-treated patients, and was 4- to 20-fold more effective than protamine. Several other peptide structures were effective in some patients' plasmas. All high-affinity peptides reversed inhibition of thrombin-induced clot formation by UFH. These peptides (1 mg/300 g rat) neutralized 1 U/mL anti–Factor Xa activity of enoxaparin in rats within 1 to 2 minutes. Direct blood pressure and heart rate measurements showed little or no hemodynamic effect. These heparin-binding peptides, singly or in combination, are potential candidates for clinical reversal of UFH and LMWH in humans.


2021 ◽  
Vol 10 (Supplement_1) ◽  
Author(s):  
A Abdul Razzack ◽  
N Hussain ◽  
S Adeel Hassan ◽  
S Mandava ◽  
F Yasmin ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background- Low molecular weight heparin (LMWH) and direct oral anticoagulants (DOACs) have been proven to be more effective in the management of venous thromboembolism (MVTE). The efficacy and safety of LMWH or DOACs in treatment of recurrent or malignancy induced VTE is not studied in literature. Objective To compare the efficacy and safety of LMWH and  DOACs in the management of malignancy induced  VTE Methods- Electronic databases ( PubMed, Embase, Scopus, Cochrane) were searched from inception to November  28th, 2020. Dichotomous data was extracted for prevention of VTE and risk of major bleeding in patients taking either LMWH or DOACs. Unadjusted odds ratios (OR) were calculated from dichotomous data using Mantel Haenszel (M-H) random-effects with statistical significance to be considered if the confidence interval excludes 1 and p &lt; 0.05.  Results- Three studies with 2607 patients (DOACs n = 1301 ; LMWH n = 1306) were included in analysis. All the study population had active cancer of any kind diagnosed within the past 6 months. Average follow-up period for each trial was 6 months. Patients receiving DOACs have a lower odds of recurrence of MVTE as compared to LMWH( OR 1.56; 95% CI 1.17-2.09; P = 0.003, I2 = 0). There was no significant difference in major bleeding among patients receiving LMWH or DOACs  (OR-0.71, 95%CI 0.46-1.10, P = 0.13, I2 = 22%) (Figure 1). We had no publication bias in our results (Egger’s regression p &gt; 0.05). Conclusion- DOACs are superior to LMWH in prevention of MVTE and have similar major bleeding risk as that of LMWH. Abstract Figure. A)VTE Recurrence B)Major Bleeding events


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