Fucosylated Chondroitin Sulfates with Rare Disaccharide Branches from the Sea Cucumbers Psolus peronii and Holothuria nobilis: Structures and Influence on Hematopoiesis.

Two fucosylated chondroitin sulfates were isolated from the sea cucumbers Psolus peronii and Holothuria nobilis using a conventional extraction procedure in the presence of papain, followed by anion-exchange chromatography on DEAE-Sephacel. Their composition was characterized in terms of quantitative monosaccharide and sulfate content, and structures were mainly elucidated using 1D- and 2D-NMR spectroscopy. As revealed by the data of the NMR spectra, both polysaccharides along with the usual fucosyl branches contained rare disaccharide branches α-D-GalNAc4S6R-(1→2)-α-L-Fuc3S4R → attached to O-3 of the GlcA of the backbone (R = H or SO3-). The polysaccharides were studied as stimulators of hematopoiesis in vitro using mice bone marrow cells as the model. The studied polysaccharides were shown to be able to directly stimulate the proliferation of various progenitors of myelocytes and megakaryocytes as well as lymphocytes and mesenchymal cells in vitro. Therefore, the new fucosylated chondroitin sulfates can be regarded as prototype structures for the further design of GMP-compatible synthetic analogs for the development of new-generation hematopoiesis stimulators.

Anti-Cancer Potential of Transiently Transfected HER2-Specific Human Mixed CAR-T and NK Cell Populations in Experimental Models: Initial Studies on Fucosylated Chondroitin Sulfate Usage for Safer Treatment.

Human epidermal growth factor receptor 2 (HER2) is overexpressed in numerous cancer cell types. Therapeutic antibodies and chimeric antigen receptors (CARs) against HER2 were developed to treat human tumors. The major limitation of anti-HER2 CAR-T lymphocyte therapy is attributable to the low HER2 expression in a wide range of normal tissues. Thus, side effects are caused by CAR lymphocyte "on-target off-tumor" reactions. We aimed to develop safer HER2-targeting CAR-based therapy. CAR constructs against HER2 tumor-associated antigen (TAA) for transient expression were delivered into target T and natural killer (NK) cells by an effective and safe non-viral transfection method via nucleofection, excluding the risk of mutations associated with viral transduction. Different in vitro end-point and real-time assays of the CAR lymphocyte antitumor cytotoxicity and in vivo human HER2-positive tumor xenograft mice model proved potent cytotoxic activity of the generated CAR-T-NK cells. Our data suggest transient expression of anti-HER2 CARs in plasmid vectors by human lymphocytes as a safer treatment for HER2-positive human cancers. We also conducted preliminary investigations to elucidate if fucosylated chondroitin sulfate may be used as a possible agent to decrease excessive cytokine production without negative impact on the CAR lymphocyte antitumor effect.

Glycosaminoglycans from the Starfish Lethasterias fusca: Structures and Influence on Hematopoiesis.

Crude anionic polysaccharides extracted from the Pacific starfish Lethasterias fusca were purified by anion-exchange chromatography. The main fraction LF, having MW 14.5 kDa and dispersity 1.28 (data of gel-permeation chromatography), was solvolytically desulfated and giving rise to preparation LF-deS with a structure of dermatan core [→3)-ß-d-GalNAc-(1→4)-α-l-IdoA-(1→]n, which was identified according to NMR spectroscopy data. Analysis of the NMR spectra of the parent fraction LF led to identification of the main component as dermatan sulfate LF-Derm →3)-ß-d-GalNAc4R-(1→4)-α-l-IdoA2R3S-(1→ (where R was SO3 or H), bearing sulfate groups at O-3 or both at O-2 and O-3 of α-l-iduronic acid, as well as at O-4 of some N-acetyl-d-galactosamine residues. The minor signals in NMR spectra of LF were assigned as resonances of heparinoid LF-Hep composed of the fragments →4)-α-d-GlcNS3S6S-(1→4)-α-l-IdoA2S3S-(1→. The 3-O-sulfated and 2,3-di-O-sulfated iduronic acid residues are very unusual for natural glycosaminoglycans, and further studies are needed to elucidate their possible specific influence on the biological activity of the corresponding polysaccharides. To confirm the presence of these units in LF-Derm and LF-Hep, a series of variously sulfated model 3-aminopropyl iduronosides were synthesized and their NMR spectra were compared with those of the polysaccharides. Preparations LF and LF-deS were studied as stimulators of hematopoiesis in vitro. Surprisingly, it was found that both preparations were active in these tests, and hence, the high level of sulfation is not necessary for hematopoiesis stimulation in this particular case.

The synthesis of hyaluronic acid related oligosaccharides and elucidation of their antiangiogenic activity.

Hyaluronic acid related di-, tri-, tetra- and hexasaccharide were synthesized as spacer-armed derivatives. 4,6-O-(p-Methoxybenzylidene-2,3-di-O-benzoyl-glucosyl sulfoxide was used as a donor for the formation of ß-D-Glc-(1 â†’ 3)-ß-D-GlcNTCA interunit bond. Selective removal of p-methoxy-benzylidene protecting group, C(6) oxidation by TEMPO-BAIB system followed by methylation led to transformation of Glc unit into GlcA one. Trichloromethyloxazoline donors were used for the formation of ß-D-GlcNTCA-(1 â†’ 4)-ß-D-GlcA linkages. Block-wise [1 + 2], [2 + 2], and [2 + 4] chain assembly afforded to corresponding tri-, tetra-, and hexasaccharide derivatives, respectively. The target compounds were studied as inhibitors of angiogenesis in vitro using endothelial cells and Matrigel as a medium to show the activity of tetra- and hexasaccharide but not for di- and trisaccharide.

Perspectives for the Use of Fucoidans in Clinical Oncology.

Fucoidans are natural sulfated polysaccharides that have a wide range of biological functions and are regarded as promising antitumor agents. The activity of various fucoidans and their derivatives has been demonstrated in vitro on tumor cells of different histogenesis and in experiments on mice with grafted tumors. However, these experimental models showed low levels of antitumor activity and clinical trials did not prove that this class of compounds could serve as antitumor drugs. Nevertheless, the anti-inflammatory, antiangiogenic, immunostimulating, and anticoagulant properties of fucoidans, as well as their ability to stimulate hematopoiesis during cytostatic-based antitumor therapy, suggest that effective fucoidan-based drugs could be designed for the supportive care and symptomatic therapy of cancer patients. The use of fucoidans in cancer patients after chemotherapy and radiation therapy might promote the rapid improvement of hematopoiesis, while their anti-inflammatory, immunomodulatory, and anticoagulant effects have the potential to improve the quality of life of patients with advanced cancer.

Fucoidans of Brown Algae: Comparison of Sulfated Polysaccharides from Fucus vesiculosus and Ascophyllum nodosum.

Preparations of sulfated polysaccharides obtained from brown algae are known as fucoidans. These biopolymers have attracted considerable attention due to many biological activities which may find practical applications. Two Atlantic representatives of Phaeophyceae, namely, Fucus vesiculosus and Ascophyllum nodosum, belonging to the same order Fucales, are popular sources of commercial fucoidans, which often regarded as very similar in chemical composition and biological actions. Nevertheless, these two fucoidan preparations are polysaccharide mixtures which differ considerably in amount and chemical nature of components, and hence, this circumstance should be taken into account in the investigation of their biological properties and structure-activity relationships. In spite of these differences, fractions with carefully characterized structures prepared from both fucoidans may have valuable applications in drug development.

Novel and Promising Strategies for Therapy of Post-Transplant Chronic GVHD.

Despite the achievements that have increased viability after the transplantation of allogeneic hematopoietic stem cells (aHSCT), chronic graft-versus-host disease (cGVHD) remains the main cause of late complications and post-transplant deaths. At the moment, therapy alternatives demonstrate limited effectiveness in steroid-refractory illness; in addition, we have no reliable data on the mechanism of this condition. The lack of drugs of choice for the treatment of GVHD underscores the significance of the design of new therapies. Improved understanding of the mechanism of chronic GVHD has secured new therapy goals, and organized diagnostic recommendations and the development of medical tests have ensured a general language and routes for studies in this field. These factors, combined with the rapid development of pharmacology, have helped speed up the search of medicines and medical studies regarding chronic GVHD. At present, we can hope for success in curing this formidable complication. This review summarizes the latest clinical developments in new treatments for chronic GVHD.

Fucose-Rich Sulfated Polysaccharides from Two Vietnamese Sea Cucumbers Bohadschia argus and Holothuria (Theelothuria) spinifera: Structures and Anticoagulant Activity.

Fucosylated chondroitin sulfates (FCSs) FCS-BA and FCS-HS, as well as fucan sulfates (FSs) FS-BA-AT and FS-HS-AT were isolated from the sea cucumbers Bohadschia argus and Holothuria (Theelothuria) spinifera, respectively. Purification of the polysaccharides was carried out by anion-exchange chromatography on DEAE-Sephacel column. Structural characterization of polysaccharides was performed in terms of monosaccharide and sulfate content, as well as using a series of non-destructive NMR spectroscopic methods. Both FCSs were shown to contain a chondroitin core [→3)-ß-d-GalNAc-(1→4)-ß-d-GlcA-(1→]n bearing sulfated fucosyl branches at O-3 of every GlcA residue in the chain. These fucosyl residues were different in pattern of sulfation: FCS-BA contained Fuc2S4S, Fuc3S4S and Fuc4S at a ratio of 1:8:2, while FCS-HS contained these residues at a ratio of 2:2:1. Polysaccharides differed also in content of GalNAc4S6S and GalNAc4S units, the ratios being 14:1 for FCS-BA and 4:1 for FCS-HS. Both FCSs demonstrated significant anticoagulant activity in clotting time assay and potentiated inhibition of thrombin, but not of factor Xa. FS-BA-AT was shown to be a regular linear polymer of 4-linked α-L-fucopyranose 3-sulfate, the structure being confirmed by NMR spectra of desulfated polysaccharide. In spite of considerable sulfate content, FS-BA-AT was practically devoid of anticoagulant activity. FS-HS-AT cannot be purified completely from contamination of some FCS. Its structure was tentatively represented as a mixture of chains identical with FS-BA-AT and other chains built up of randomly sulfated alternating 4- and 3-linked α-L-fucopyranose residues.

Depolymerization of a fucosylated chondroitin sulfate from Cucumaria japonica: Structure and activity of the product.

Fucosylated chondroitin sulfate CJ from the body wall of sea cucumber Cucumaria japonica was depolymerized by the treatment with H2O2 in the presence of Cu(OAc)2. The molecular weight of the polysaccharide was decreased from 32 kDa to 5 kDa. The product CJ-DP was shown to contain l-Fuc, d-GalNAc, d-GlcA, and sulfate in molar proportions of 0.96:0.90:1.00:5.4, which were quite similar to those of the parent polysaccharide CJ. The NMR analysis revealed that CJ-DP, like the parent polysaccharide CJ, consisted of both branched →4)-[3-O-α-l-Fuc]-ß-d-GlcA-(1 â†’ 3)-ß-d-GalNAc-(1→ and linear →4)-ß-d-GlcA-(1 â†’ 3)-ß-d-GalNAc-(1→ repeating blocks. Sulfate groups occupy O-4 and the majority of O-6 of GalNAc, as well as O-3 of GlcA, in linear blocks and different positions in Fuc branches. This result indicates that depolymerization practically does not diminish the amount of branches and sulfate groups in the product. Both polysaccharides CJ and CJ-DP demonstrated anticoagulant and hematopoiesis-stimulatory activities in vitro.

Antiaggregant effects of (1,2,5-oxadiazolyl)azasydnone ring assemblies as novel antiplatelet agents.

A series of biheterocyclic assemblies comprising of 1,2,5-oxadiazole and azasydnone scaffolds were synthesized and biologically evaluated as novel nitric oxide (NO)-donor and antiplatelet agents. Depending on functional substituents at the biheterocyclic core, all studied compounds demonstrated good NO-donor profiles releasing NO in a wide range of concentrations (19.2%-195.1%) according to a Griess assay. (1,2,5-Oxadiazolyl)azasydnones showed excellent antiplatelet activity in the case of ADP and adrenaline used as inducers completely suppressing the aggregate formation even at the lowest test concentration of 0.0375 µmol/ml, which is a rather unique feature. Moreover, studied biheterocycles possess a selective mechanism of inhibition of platelet aggregation mediated only by ADP and adrenaline, which are considered to be the main inducers causing thrombus formation. In addition, (1,2,5-oxadiazolyl)azasydnones were found to be completely non-toxic to hybrid endothelial cells EaHy 926. Studies of hydrolytic degradation of the synthesized compounds afforded benzoic acid as a sole detectable decomposition product, which is considered advantageous in drug design. Therefore, (1,2,5-oxadiazolyl)azasydnones represent a novel class of promising drug candidates with improved antiplatelet profile and reduced toxicity enabling their huge potential in medicinal chemistry and drug design.

Chondroitin Sulfate and Fucosylated Chondroitin Sulfate as Stimulators of Hematopoiesis in Cyclophosphamide-Induced Mice.

The immunosuppression and inhibition of hematopoiesis are considered to be reasons for the development of complications after intensive chemotherapy and allogeneic hematopoietic stem cell transplantation. Chondroitin sulfate (CS), isolated from the fish Salmo salar, and fucosylated chondroitin sulfate (FCS), isolated from the sea cucumber Apostichopus japonicus, were studied for their roles as stimulators of hematopoiesis in a model of cyclophosphamide-induced immunosuppression in mice. The recombinant protein r G-CSF was applied as a reference. The studied polysaccharides were shown to stimulate the release of white and red blood cells, as well as platelets from bone marrow in immunosuppressed mice, while r G-CSF was only responsible for the significant increase in the level of leucocytes. The analysis of different populations of leucocytes in blood indicated that r G-CSF mainly stimulated the production of neutrophils, whereas in the cases of the studied saccharides, increases in the levels of monocytes, lymphocytes and neutrophils were observed. The normalization of the level of the pro-inflammatory cytokine IL-6 in the serum and the recovery of cell populations in the spleen were observed in immunosuppressed mice following treatment with the polysaccharides. An increase in the proliferative activity of hematopoietic cells CD34(+)CD45(+) was observed following ex vivo polysaccharide exposure. Further study on related oligosaccharides regarding their potential as promising drugs in the complex prophylaxis and therapy of hematopoiesis inhibition after intensive chemotherapy and allogeneic hematopoietic stem cell transplantation seems to be warranted.

Oversulfated dermatan sulfate and heparinoid in the starfish Lysastrosoma anthosticta: Structures and anticoagulant activity.

Crude anionic polysaccharides extracted from the Pacific starfish Lysastrosoma anthosticta were separated by anion-exchange chromatography into fractions LA-F1 and LA-F2. The main fraction LA-F1 was solvolytically desulfated giving rise to preparation LA-F1-DS with a structure of dermatan core [→3)-ß-d-GalNAc-(1→4)-α-l-IdoA-(1→]n. Reduction of LA-F1 afforded preparation LA-F1-RED composed mainly of the repeating disaccharide units →3)-ß-d-GalNAc4R-(1→4)-α-l-Ido2S3S-(1→, where R was SO3- or H. Analysis of the NMR spectra of the parent fraction LA-F1 led to determine the main component as the oversulfated dermatan sulfate LA-Derm bearing sulfate groups at O-2 and O-3 of α-l-iduronic acid, as well as at O-4 of some N-acetyl-d-galactosamine residues. The minor fraction LA-F2 contained a mixture of LA-Derm and heparinoid LA-Hep, the latter being composed of the fragments →4)-α-d-GlcNS3S6S-(1→4)-α-l-IdoA2S3S-(1→ and →4)-α-d-GlcNS3S-(1→4)-α-l-IdoA2S3S-(1→. The presence of 2,3-di-O-sulfated iduronic acid residues is very unusual both for natural dermatan sulfate and heparinoid. Preparations LA-F1, LA-F2 and LA-F1-RED demonstrated significant anticoagulant effect in vitro.

Fucosylated Chondroitin Sulfates from the Sea Cucumbers Paracaudina chilensis and Holothuria hilla: Structures and Anticoagulant Activity.

Fucosylated chondroitin sulfates (FCSs) PC and HH were isolated from the sea cucumbers Paracaudina chilensis and Holothuria hilla, respectively. The purification of the polysaccharides was carried out by anion-exchange chromatography on a DEAE-Sephacel column. The structural characterization of the polysaccharides was performed in terms of monosaccharide and sulfate content, as well as using a series of nondestructive NMR spectroscopic methods. Both polysaccharides were shown to contain a chondroitin core [→3)-ß-d-GalNAc (N-acethyl galactosamine)-(1→4)-ß-d-GlcA (glucuronic acid)-(1→]n, bearing sulfated fucosyl branches at O-3 of every GlcA residue in the chain. These fucosyl residues were different in their pattern of sulfation: PC contained Fuc2S4S and Fuc4S in a ratio of 2:1, whereas HH included Fuc2S4S, Fuc3S4S, and Fuc4S in a ratio of 1.5:1:1. Moreover, some GalNAc residues in HH were found to contain an unusual disaccharide branch Fuc4S-(1→2)-Fuc3S4S-(1→ at O-6. Sulfated GalNAc4S6S and GalNAc4S units were found in a ratio of 3:2 in PC and 2:1 in HH. Both polysaccharides demonstrated significant anticoagulant activity in a clotting time assay, which is connected with the ability of these FCSs to potentiate the inhibition of thrombin and factor Xa in the presence of anti-thrombin III (ATIII) and with the direct inhibition of thrombin in the absence of any cofactors.

Fucosylated chondroitin sulfate from the sea cucumber Hemioedema spectabilis: Structure and influence on cell adhesion and tubulogenesis.

Fucosylated chondroitin sulfate (FCS) HeSp was isolated from the Patagonian sea cucumber Hemioedema spectabilis. Ion-exchange chromatography was applied for purification of the FCS from the crude extract of sulfated polysaccharides. Analysis of monosaccharide and sulfate content of HeSp revealed the molar ratio of GlcA:GalNAc:Fuc:SO3Na as 1.15:1:1.1:3.9. Molecular weight of HeSp (44.1 kDa) was determined by GPC. According to the NMR spectral data, the main fragment of HeSp was the trisaccharide →3)-ß-d-GalNAc-(1→4)-ß-d-GlcA(3-O-α-l-Fuc)-(1→, where GalNAc units were sulfated either at O-4, at O-6 or both at O-4 and O-6. The fucosyl branches attached to O-3 of GlcA showed also different patterns of sulfation: Fucp2S4S, Fucp4S and Fucp3S4S were found in a ratio of 3.8:1.5:1. Besides, small amounts of the disaccharide fragment →3)-ß-d-GalNAc-(1→4)-ß-d-GlcA3S-(1→ were observed in a structure of HeSp. The polysaccharide was found to block cancer cells adhesion to platelet-coated surface and to inhibit tubulogenesis, thus demonstrating the potential antitumor activity.

Structural analysis of holothurian fucosylated chondroitin sulfates: Degradation versus non-destructive approach.

Fucosylated chondroitin sulfates (FCS) are unique glycosaminoglycans isolated from the body walls of sea cucumbers (holothuria). These biopolymers are composed of a chondroitin core [→4)-ß-d-GlcA-(1 → 3)-ß-d-GalNAc-(1→]n bearing fucosyl branches and the sulfate groups. Fucosyl substituents prevent enzymatic degradations of FCS by chondroitinases, which are effectively used in the structural analysis of vertebrate chondroitin sulfates, and hence, several non-enzymatic approaches to structural elucidation of FCS have been developed. They include combination of chemical modifications, specific degradation of polymeric chain and spectroscopic investigations of the products. In addition, there are examples of successful determination of the structure of non-modified FCS using NMR spectroscopic methods. NMR spectroscopy is especially effective in characterization of molecules with regular distribution of substituents along the polymeric chains. Otherwise combination of both chemical and spectroscopic methods is required for unambiguous elucidation of non-regular FCS structures. Structural variations of FCS studied up to now were shown to be species specific and include differences in type, amount and position of branches, as well as in degree and pattern of sulfation. These features of FCS can modify significantly the spectrum of their biological activities. In this mini-review the scopes and limitations of different approaches to FCS structure determination are concisely described and compared.

Synthesis of a biotinylated probe from biotechnologically derived ß-d-mannopyranosyl-(1 → 2)-d-mannopyranose for assessment of carbohydrate specificity of antibodies.

The disaccharide ß-d-mannopyranosyl-(1 → 2)-d-mannopyranose obtained by chemical cleavage and enzymatic dephosphorylation of biotechnologically available phosphomannan was transformed over six steps into a biotinylated probe suitable for assessment of carbohydrate specificity of antibodies induced by yeast cell wall preparations.

Structure and Anti-Inflammatory Activity of a New Unusual Fucosylated Chondroitin Sulfate from Cucumaria djakonovi.

Fucosylated chondroitin sulfate CD was isolated from the sea cucumber Cucumaria djakonovi collected from the Avachinsky Gulf of the eastern coast of Kamchatka. Structural characterization of CD was performed using a series of non-destructive NMR spectroscopic procedures. The polysaccharide was shown to contain a chondroitin core [→3)-ß-d-GalNAc-(1→4)-ß-d-GlcA-(1→]n where about 60% of GlcA residues were 3-O-fucosylated, while another part of GlcA units did not contain any substituents. The presence of unsubstituted both at O-2 and O-3 glucuronic acid residues in a structure of holothurian chondroitin sulfate is unusual and has not been reported previously. Three different fucosyl branches Fucp2S4S, Fucp3S4S and Fucp4S were found in the ratio of 2:1:1. The GalNAc units were mono- or disulfated at positions 4 and 6. Anti-inflammatory activity of CD was assessed on a model of acute peritoneal inflammation in rats. About 45% inhibition was found for CD, while a structurally related linear chondroitin sulfate SS from cartilage of the fish Salmo salar demonstrated only 31% inhibition, indicating that the presence of sulfated fucosyl branches is essential for anti-inflammatory effect of chondroitin sulfates of marine origin.

Influence of Modified Fucoidan and Related Sulfated Oligosaccharides on Hematopoiesis in Cyclophosphamide-Induced Mice.

Immunosuppression derived after cytostatics application in cancer chemotherapy is considered as an adverse side effect that leads to deterioration of quality of life and risk of infectious diseases. A linear sulfated (1→3)-α-l-fucan M-Fuc prepared by chemical modification of a fucoidan isolated from the brown seaweed Chordaria flagelliformis, along with two structurally related synthetic sulfated oligosaccharides, were studied as stimulators of hematopoiesis on a model of cyclophosphamide immunosuppression in mice. Recombinant granulocyte colony-stimulating factor (r G-CSF), which is currently applied in medicine to treat low blood neutrophils, was used as a reference. Polysaccharide M-Fuc and sulfated difucoside DS did not demonstrate significant effect, while sulfated octasaccharide OS showed higher activity than r G-CSF, causing pronounced neutropoiesis stimulation. In addition, production of erythrocytes and platelets was enhanced after the octasaccharide administration. The assessment of populations of cells in blood and bone marrow of mice revealed the difference in mechanisms of action of OS and r G-CSF.

A sulfated galactofucan from the brown alga Hormophysa cuneiformis (Fucales, Sargassaceae).

The brown alga Hormophysa cuneiformis collected from the coastal waters of Vietnam was used to isolate a mixture of sulfated polysaccharides FHC, which was fractionated further by anion-exchange chromatography on DEAE-Sephacel. The main fraction F3 eluted with 1.5 M NaCl contained essentially l-fucose, d-galactose and sulfate and has very complex NMR spectra. Desulfation to obtain F3deS followed by Smith degradation to obtain F3deS-Sm was used to simplify the structure of F3, and all these preparations were characterized by methylation analysis and NMR spectra. A linear (1 → 3)-linked backbone built up of α-l-fucopyranose residues was identified as the main structural motif of molecules. Some fucose residues attached to position 4 of its 3-linked neighbor were found as branches. Galactose residues having both α- and ß-configurations were found mostly at the periphery of molecules. They are present as (1 → 6)-linked disaccharide of two ß-d-Galp attached to position 4 of the backbone or as single α-d-Galp attached to the same position. Sulfate groups in F3 may probably occupy any positions of the molecule. F3 acts as anticoagulant and is about half as active as the standard low-molecular mass heparin (enoxaparin). FHC was practically inactive in cytotoxicity test against six human cancer cell lines.

Fucosylated chondroitin sulfates from the sea cucumbers Holothuria tubulosa and Holothuria stellati.

Two polysaccharides HT and HS were isolated from the sea cucumbers Holothuria tubulosa and Holothuria stellati, respectively. Purification of the natural polymers was performed by consecutive ion-exchange and gel permeation chromatography. The molar ratio of the monosaccharides and sulfate GlcA:GalNAc:Fuc:SO3Na was determined as 12:14:17:57 for HT and 12:12:16:60 for HS indicating that both polysaccharides are fucosylated chondroitin sulfates. Detailed structural characterization of HT and HS was performed using the 1D and 2D NMR spectroscopic methods. The main chain of HT and HS was shown to consist of alternating →4)- ß-d-GlcA-(1→ and →3)-ß-d-GalNAc-(1→ sequence, where the latter unit was sulfated at O-4 or both at O-4 and O-6. The ratio of GalNAc4S:GalNAc4S6S was determined as 1:4 for HT and 1:4.5 for HS. Three types of sulfated fucosyl branches Fucp2S4S, Fucp3S4S and Fucp4S attached to O-3 of glucuronic acid residues were found in a ratio of 3:3:1 for HT and 2:2:1 for HS.