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This study was supported by Federal University of Rio Grande do Norte. Federal University of Rio Grande do Norte - Campus Universit?rio. Department of Biochemistry. Natal, RN, Brazil. Federal University of Rio Grande do Norte. Postgraduate Program in Health Sciences. Natal, RN, Brazil. Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Programa de P?s-Gradua??o em Virologia. Ananindeua, PA, Brasil. Federal University of Rio Grande do Norte - Campus Universit?rio. Department of Biochemistry. Natal, RN, Brazil. Federal University of Rio Grande do Norte. Department of Clinical Analysis and Toxicology. Natal, RN, Brazil. Federal University of Rio Grande do Norte - Campus Universit?rio. Department of Biochemistry. Natal, RN, Brazil. Federal University of Campina Grande. Center of Education and Health. Cuit?, PB, Brazil. Federal University of Rio Grande do Norte - Campus Universit?rio. Department of Biochemistry. Natal, RN, Brazil. Background: According to the World Health Organization (WHO), two-fifths of the world population is at risk of infection by DENV. There are no safe and effective vaccines estab-lished. Sulfated glycosaminoglycans such as heparin, used as anticoagulants, inhibit the initial step of dengue viral replication. Recently, an isolated heparin analogue Goniopsis cruentata (cCTH) has presented a low anticoagulant effect with reduced bleeding risk. Methods: The antiviral activity of cCTH and heparin compounds against DENV-2 in Vero cell culture was determined by quantitative RT-PCR (qRT-PCR) and titration. For this, four trials were carried out: treatment of the cells for 2 h before viral inoculation, concomitant viral inoculation treatment, treatment after viral inoculation and virucidal assay. Subsequently, the culture superna-tants were collected for periods of 24, 48 and 72 h. Results: Our results demonstrated that cCTH and heparin showed antiviral activity against DENV-2. Conclusion: These data suggest that both compounds prevented viral replication in cultured Vero cells.

Plasma cell disorders are known to be associated with bleeding and thrombotic tendencies. Etiology of bleeding can be thrombocytopenia, platelet dysfunction, amyloidosis, heparin like anticoagulant...

Research into the design of heparin and heparin-like/mimicking polymer-functionalized biomedical membranes is of tremendous interest to the biomedical sector in particular and is driven by potential diverse biomedical applications such as blood purification, artificial organs and other clinical medical devices. In this review, we highlight the progress of the recent research and propose potential biomedical applications in the fields of surface heparinization and the heparin-inspired modification of polymeric membranes. We summarize various surface heparinization strategies such as blending, surface coating, grafting, layer-by-layer assembly and mussel-inspired coating. Then, we classify the heparin-like/mimicking polymers and their applications in the design of heparin-mimicking biomedical membranes and draw some conclusions. The general concept of heparin-like/mimicking polymers is usually defined as heparan sulfates or synthetic sulfated/carboxylated polymers with comparable biologically mimicking functionalities as heparin, especially anticoagulant activity. Moreover, the potential biomedical applications and benefits of heparin and heparin-like/mimicking polymer-functionalized membranes in blood purification, artificial organs and tissue engineering are also discussed in each section. The heparin and heparin-like/mimicking polymer-functionalized membranes presented are exceptional candidates for the treatment of organ failure and many other blood-contacting fields. Finally, we conclude with the challenges and future perspectives for the strategies toward the heparinization and heparin-like/mimicking modification of membrane surfaces. It is believed that this review will evoke more attention towards the design of heparinized and heparin-like/mimicking membranes and encourage future advancements of this emerging research field.

Background Heparin and heparin-like molecules have shown some promise in the treatment of several cancers. These molecules have roles in angiogenesis, cell proliferation, immune system modulation, cell migration, and cellular invasion. The pathways and mechanisms used by these molecules to inhibit the proliferation of cancer cells aid in understanding the utilization of these molecules in potential treatments. Our aim is to review the use of heparin and heparin-like molecules in cancer treatment, explore the results, and discuss their potential downfalls. Methods Publications on heparin and heparin-like molecules and compounds were collected from the PubMed and EMBASE databases. Boolean operators and MeSH terms related to heparin, heparin-like molecules, and cancer were used to conduct this search. The articles were reviewed by the authors. Results Several heparin mimetics are showing promise in cancer treatment. Various studies using mimetics alone or in combination with chemotherapy have been conducted and have yielded mixed results. They work on multiple target molecules, mostly receptors such as fibroblast growth factor and endothelial growth factor. The main types of cancers targeted by these drugs are multiple myeloma, pancreatic cancer, hepatocellular carcinoma (HCC), and other solid tumors. Conclusion Although limited clinical evidence of efficacy and potential pitfalls are present, heparin and heparin-like molecules have shown potential in the management of cancer patients. Additional research is required to fully understand the biological mechanisms utilized by these molecules in cancer treatment.

Well-defined heparin like oligosaccharides up to decasaccharides were synthesized. It was discovered for the first time that heparin oligosaccharides, as short as tetrasaccharides, can bind with the most toxic tau species, i.e., tau oligomers with nM KD. The binding significantly reduced the cellular uptake of toxic tau oligomers and protected the cells from tau oligomer induced cytotoxicity.

A series of heparin-like 6-carboxylchitin derivatives with different N-acetyl group and sulfate group contents were prepared. Their structures were characterized by element analysis, FT-IR, 13 C NMR, and gel permeation chromatography. Their anticoagulant activity in vitro was investigated for human plasma with respect to activated partial thromboplastin time (APTT). The results showed all 6-carboxylchitin derivatives prolonged APTT within the scope of studied degree of sulfation (0.28–1.03) and Mws (4.3–13.7 kDa). Their anticoagulant activity strongly depended on their structures. 3,6-O-sulfated group promoted the anticoagulant activity. Only incorporation of N-sulfated group into deacetylated 6-carboxylchitin could not improve the anticoagulant activity. But, N-sulfated group and O-sulfated group had the synergistic action, and N-sulfated group could promote the anticoagulant activity for the N,O-sulfated chitin derivatives. In addition, acetyl group took a role in the anticoagulant activity, too.

Disaccharide units containing a latent aldehyde surrogate at O4 provide late-stage access to terminal aldehyde LMWH and HS deca and dodecasaccharides., d-Glucosamine derivatives bearing latent O4 functionality provide modified H/HS-type disaccharide donors for a final stage capping approach enabling introduction of conjugation-suitable, non-reducing terminal functionality to biologically important glycosaminoglycan oligosaccharides. Application to the synthesis of the first O4-terminus modified synthetic LMWH decasaccharide and an HS-like dodecasaccharide is reported.

A heparin-like hexasaccharide structure (2) containing the two trisaccharide sequences that interact with acidic fibroblast growth factor (FGF-1) and with its receptor (FGFR) has been designed on the basis of crystallographic data. This hexasaccharide has been effectively synthesized by a completely stereoselective modular approach and biologically evaluated by determination of its capacity to stimulate FGF-1-induced mitogenic activity. It was found that this molecule did not show an appreciable FGF-1 activating effect. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

The development of alternative prosthetic materials for cardiovascular applications has found growing interest due to the failure to date to be able to implement functional patent small diameter vascular grafts (∅

Heparin-like hexasaccharide 3 and octasaccharide 4 have been synthesized using a convergent block strategy and their solution conformations have been determined by NMR spectroscopy. Both oligosaccharides contain the basic structural motif of the regular region of heparin but have been constructed as to display negatively charged sulfate groups only on one side of their solution helical structures. This charge distribution along the saccharide chain has been designed to get insight into the proposed mechanism for fibroblast growth factors (FGFs) activation that involves heparin-induced FGF dimerization.Key words: heparin oligosaccharides, synthesis design, conformational analysis, FGF activation.

A new low-molecular-weight 'heparin-like' component was obtained from an exopolysaccharide produced by a mesophilic strain found in deep-sea hydrothermal vents. Data concerning the structure of the native high-molecular-weight exopolysaccharide (10(6) g/mol, 10% sulfate content) are reported for the first time. Two depolymerization processes were used to obtain low-molecular-weight (24-35 x 10(3) g/mol) oversulfated fractions (sulfate content 20 or 40%), Nuclear magnetic resonance studies indicated that after sulfation (40%), the low-molecular-weight fraction obtained by free radical depolymerization was less sulfated in the 6-O-position than the fraction depolymerized by acid hydrolysis. The free radical depolymerized product also had sulfated residues in the 4-O-position and disulfated ones in the 2,3-O-positions. Moreover, the compounds generated by the free radical process were more homogeneous with respect to molecular mass. Also for the first time, the anticoagulant activity of the low-molecular-weight exopolysaccharide fractions is reported. When the fractions obtained after sulfation and depolymerization were compared with heparins, anticoagulant activity was detected in oversulfated fractions, but not in native exopolysaccharide. The free radical depolymerized fraction inhibited thrombin generation in both contact-activated and thromboplastin-activated plasma, showing a prolonged lag phase only in the contact-activated assay. Affinity co-electrophoresis studies suggested that a single population of polysaccharide chains binds to antithrombin and that only a subpopulation strongly interacts with heparin cofactor II. (C) 2001 Elsevier Science B.V. All rights reserved.

The binding of Ca2+ to synthetic hexasaccharide 1, containing the structural motifs of the regular region of heparin, has been investigated using NMR spectroscopy and molecular modeling. The NMR data of the calcium salt of 1 indicate the existence of specific Ca2+ binding, and molecular modeling results predict three different types of binding sites with different negative potential and preorganized geometry. The presence of Ca2+ does not seem to affect the overall helical structure of hexasaccharide 1, although it seems to have a marked influence on the flexibility of the oligosaccharide backbone.

After the discovery of a unique pentasaccharide domain in heparin that is responsible for activation of antithrombin 111, many analogues have been synthesised which stimulate the inhibition of factor Xa. Some aspects of the synthesis of heparin like pentasaccharides are presented. Furthermore, pentasaccharide conjugates could be designed and synthesised which stimulate the antithrombin I11 mediated inhibition of both factor Xa and thrombin.

We report the second case of an acquired heparin-like anticoagulant in a patient with disseminated breast carcinoma. All but one of the small numbers of other cases have also been associated with an underlying malignancy. We comment on the distinction between an immunoglobulin and proteoglycan causing the antithrombin effect and suggest points of interest for consideration in any future cases together with a review of treatment options.

Hyaluronic acid was sulphated and seven derivatives, containing a different number of sulphated groups per disaccharide unit, were prepared (HyalSx, where x can be I, 2,2.5,3,3.5,3.8,4). The behaviour of the sulphated hyaluronic acids was studied at different pH's by using several thermodynamic and spectroscopic techniques. The ability of these macromolecules to form Cu2+ complexes in aqueous solution was also investigated. The sulphated hyaluronic acids were studied as heparin-like molecules, thus coagulation and angiogenesis in-vitro tests were performed. The influence of the degree of sulphation on the biological activity is well documented.

A concise chemical synthesis of a series of structurally-defined heparin-like oligosaccharides is described. This work provides an efficient entry to octa-, deca-, and dodecasaccharides, including the first synthesis of (GlcNS6S-IdoA2S)5 and (GlcNS6S-IdoA2S)6. Evaluation of the in vitro activity of these species against FGF2- and VEGF165- dependent endothelial cell proliferation and migration establishes that octa- and decasaccharides are more potent in targeting FGF2-induced effects, where cell migration is affected more significantly than proliferation. These structure-activity relationships exemplify the significance of 6-O-sulfation in regulating the activity of angiogenic growth factors. © 2013 The Royal Society of Chemistry.

The sulfated tetrasaccharide β-maltosyl-(1→4)-α,α-trehalose 2 with high antiproliferative activity on smooth muscle cells was modified in the maltosyl moiety by linking eight different disaccharides equatorially to trehalose; the biological activity varied strongly between different structures.

Investigation of the smooth muscle cell antiproliferative activities of Trestatin A sulfate substructures showed that a sulfated pentasaccharide is required to maintain a heparin-like effect. The modification of one glycosidic bond led to a synthetically readily available tetrasaccharide, namely sulfated β-maltosyl trehalose12, with similar antiproliferative but devoid of anticoagulant acitivity.

The synthesis of analogues of biologically active heparin pentasaccharide fragments is reported. Replacement of N-sulphate by O-sulphate esters and introduction of various O-alkyl ethers resulted in biologically active “non-glycosamino“glycans. The biological activity can be further modulated by changing the nature and the position of the alkyl chains introduced.

To simplify the preparation of biologically active oligosaccharide analogues of glycosaminoglycan fragments we describe an approach where N-sulphates are replaced by O-sulphates and free hydroxyls are substituted by methyl groups. In this communication we report on the synthesis of a pentasaccharide in which hydroxyl groups of the non-reducing end disaccharide sub-region are methylated. The biological properties of this chemically modified analogue are fully preserved.

The synthesis is reported of a new heparin-like pentasaccharide fragment in which the reducing end glucosamine unit is replaced by a glucose residue. This indicates that an O-sulfate can be substituted for a N-sulfate thereby allowing simpler synthesis of this kind of compounds. A new route using a trisaccharide imidate as glycosyl donor was developed for this preparation.

Separation of basophilic granulocytes from peripheral blood was carried out by counterflow centrifugation elutriation using a JE-6B roter. The release of histamine and heparin-like substance from basophilic leucocytes was estimated in healthy and asthmatic subjects. 1. The number of basophils was maximal (0.74 x 10(5] at a flow rate of 4.5 ml/min, and the purity reached a peak (11.8 +/- 2.0%) at a flow rate of 9 ml/min. 2. The content of histamine paralleled the number of basophils in each fraction. 3. The release mechanism of histamine induced by anti-IgE was similar to that of the heparin-like substance. 4. The release of histamine and the heparin-like substance was significantly higher in atopic asthmatics than in non-atopic cases.

A 37-year-old female patient with systemic mastocytosis who was admitted with severe unexplained bleeding symptoms is studied. Laboratory procedures established the diagnosis of a patient-derived—heparin-like anticoagulant as a very rare hemostatic abnormality predisposing to bleeding. The patient died from refractory disease despite therapy with protamine, initiation of chemotherapy, and supportive measures. The case illustrates the clinical presentation and diagnosis of heparin-like anticoagulants. Etiology, pathophysiology, and therapeutic options are discussed.

A novel flexible assembly strategy is described for the modular synthesis of heparin and heparan sulfates. The reported strategy uses monomeric building blocks to construct the oligosaccharide chain to attain a maximum degree of flexibility. In the assembly, 1-hydroxyl glucosazido- and 1-thio uronic acid donors are combined in a sequential glycosylation protocol using sulfonium triflate activator systems. The key 1-thio uronic acids were obtained in an efficient manner from diacetone glucose employing a chemo- and regioselective oxidation of partially protected glucose and idose thioglycosides.

2 páginas, 1 figura, 1 tabla, esquemas., The first direct NMR determination of the conformation of a conformationally flexible heparin-like hexasaccharide bound to a key receptor, FGF-1, is described. The determination has been based on the use of a 13C-labeled protein and a regular 12C sugar. FGF-1 recognizes several conformations of the iduronic moieties of the hexasaccharide. Therefore, this case is different than that described for the controversial recognition of heparin-like saccharides by AT-III, which seems to recognize just one conformation of the iduronic acid residues., Financial support by DGICYT (BQU2003-03550, BQU2002-03734, BIO2002-00305) is acknowledged. We also thank Fundación Ramón Areces and Francisco Cobos for fellowships to J.A. and R.O.

The key features of a modular n+2 strategy for a completely stereoselective synthesis of oligosaccharides containing the GlcN−IdoA repeating unit of the major sequence of heparin are presented and discussed in detail. These key features include the regio- and stereoselective synthesis of disaccharide building blocks and the reactivity of building blocks in the modular assembly process. The synthetic strategy, the effectiveness of which has previously been demonstrated by the total synthesis of four hexasaccharides and two octasaccharides, allows the size and the charge distribution of the target oligosaccharide fragments to be controlled. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003

Based on previously developed solution phase chemistry, an effective general approach to the synthesis of heparin-like oligosaccharides on a soluble polymer support is reported.

Two new heparin-like hexasaccharides, 5 and 6, have been synthesised using a convergent block strategy and their solution conformations have been determined by NMR spectroscopy and molecular modelling. Both hexasaccharides contain the basic structural motif of the regular region of heparin but with negative charge distributions which have been designed to get insight into the mechanism of fibroblast growth factors (FGFs) activation.

The effective preparation of differentially protected l -iduronic acid derivatives, as building blocks for the synthesis of heparin-like oligosaccharides, is described in less than nine steps starting from readily available 1,2- O -isopropylidene-6,3- d -glucuronolactone. The pivaloyl group was used as a permanent protecting group of hydroxyl groups. Two heparin-like disaccharides with different sulfation pattern have been prepared by using these l -iduronic acid building blocks.

Fibroblast growth factor (FGF) 1 and FGF-2 are prototypic members of the FGF family, which to date comprises at least 18 members. Surprisingly, even though FGF-1 and FGF-2 share more than 80% sequence similarity and an identical structural fold, these two growth factors are biologically very different. FGF-1 and FGF-2 differ in their ability to bind isoforms of the FGF receptor family as well as the heparin-like glycosaminoglycan (HLGAG) component of proteoglycans on the cell surface to initiate signaling in different cell types. Herein, we provide evidence for one mechanism by which these two proteins could differ biologically. Previously, it has been noted that FGF-1 and FGF-2 can oligomerize in the presence of HLGAGs. Therefore, we investigated whether FGF-1 and FGF-2 oligomerize by the same mechanism or by a different one. Through a combination of matrix-assisted laser desorption ionization mass spectrometry and chemical crosslinking, we show here that, under identical conditions, FGF-1 and FGF-2 differ in the degree and kind of oligomerization. Furthermore, an extensive analysis of FGF-1 and FGF-2 uncomplexed and HLGAG complexed crystal structures enables us to readily explain why FGF-2 forms sequential oligomers whereas FGF-1 forms only dimers. FGF-2, which possesses an interface capable of protein association, forms a translationally related oligomer, whereas FGF-1, which does not have this interface, forms only a symmetrically related dimer. Taken together, these data show that FGF-1 and FGF-2, despite their sequence homology, differ in their mechanism of oligomerization.

The natural product heparin has turned out to be an important lead for the research on antithrombotics. By systematic modification of synthetic heparin fragments new derivatives were discovered. One of them, the synthetic counterpart of the antithrombin III binding pentasaccharide 1, is now being tested clinically. Recently, the structure elucidation of a number of blood coagulation proteins initiated a new breakthrough in the anticoagulant research. Molecular modelling of the crucial antithrombin III — heparin — thrombin complex inspired the design and synthesis of a novel class of anticoagulants. Their anticoagulant properties can be adjusted in a rational way leading to compounds with unprecedented characteristics. The heparin story illustrates the weaknesses and strengths of molecular modelling and structure-based design in drug discovery.