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1.
羊栖菜褐藻糖胶抗凝血活性的研究   总被引:7,自引:2,他引:7  
本文研究了羊栖菜褐藻糖胶的化学组成和抗凝血活性之间的关系。采用热水提取得羊栖菜粗多糖,CaCl2纯化得褐藻糖胶,DEAE Sepharose CL-6B柱层析与Sepharose CL-6B柱层析对褐藻糖胶进行分级,得到F1、F2、F31、F32和F33五个级分,均为岩藻糖、半乳糖和甘露糖等糖基组成的杂多糖,并含有硫酸酯和糖醛酸以及少量的蛋白质,相对分子质量范围2.5万~95万。采用活化部分凝血活酶时间(APTT)和凝血酶时间(TT)检测了这5个级分的抗凝血活性,结果显示,羊栖菜褐藻糖胶能显著延长APTT的凝血时间,而对TT的影响不明显。F1、F31和F32对APTT的影响比较显著,而F2、F33和羊栖菜粗多糖的影响较小。研究表明,羊栖菜褐藻糖胶主要是通过抑制内源凝血途径而达到抗凝血的效果,其抗凝血活性与褐藻糖胶的硫酸基含量成正相关,而与相对分子质量和糖醛酸含量无关。  相似文献   

2.
The predominant repeating structure of a fraction of the fucoidan from Ascophyllum nodosum prepared by acid hydrolysis and centrifugal partition chromatography (LMWF) was established as: [-->3)-alpha-L-Fuc(2SO3-)-(1-->4)-alpha-L-Fuc(2,3diSO3-)-(1]n by NMR spectroscopy and methylation analysis. The proton and carbon NMR spectra of this unit have been assigned and found to correspond with features in the spectra of the whole purified fucan from A. nodosum which account for most of the integrated intensity. The same structure has also been recognised in the fucoidan of Fucus vesiculosus. The fraction LMWF has in vitro anticoagulant activity, indicating that the above structure may be partly responsible for biological activity in the native fucoidan.  相似文献   

3.
A fucoidan fraction from Ascophyllum nodosum.   总被引:2,自引:0,他引:2  
A fucoidan fraction was purified from the brown alga Ascophyllum nodosum. The polysaccharide contained L-fucose and sulfate as the only constituents. Combination of methylation analysis, Smith degradation, FTIR and NMR spectroscopy on the native and the de-sulfated polymers demonstrated that the fucoidan consisted of a highly branched core region with primarily alpha-(1-->3)-linked fucosyl residues and a few alpha-(1-->4) linkages. Branch points were at position 2 of the -->3-linked internal residues. The side chains consisted of single and multi-unit fucosyl residues. The combined analytical data suggested also a complex sulfation pattern with substitution principally at position 2 and/or position 4. Such diversity in the structural features of this fucoidan may be of importance for its various biological properties.  相似文献   

4.
Fucoidan from Cladosiphon okamuranus and its sulfate derivatives were prepared. Sulfate contents of native and oversulfated fucoidan were estimated to be 13.5% and 32.8%, respectively. The results of (1)H NMR suggest that 2,4-di-O-sulfo-, 2-mono-O-sulfo- and 4-mono-O-sulfo-l-fucopyranose were involved in oversulfated fucoidan and 4-mono-O-sulfo-l-fucopyranose was involved in native fucoidan. The oversulfated fucoidan reduced the proliferation of U937 cells in a dose-dependent manner, but the activity of native fucoidan was weak. The sulfate content and substituting position of sulfate group might be important factors of anti-proliferative activity in U937 cells. To examine whether the anti-proliferative activity of oversulfated fucoidan was caused by induction of apoptosis, apoptosis assay, caspase-3 activity assay and Western blotting analysis were performed. These results indicated that the oversulfated fucoidan induced apoptosis via caspase-3 and -7 activation-dependent pathway.  相似文献   

5.

In this study, citric acid was applied as a safe organic acid for the treatment of the brown macroalga Sargassum latifolium to facilitate the sequential extraction of fucoidan and alginate without cross contamination. Box-Behnken experimental design was used to investigate the effects of citric acid concentration, temperature, and time on fucoidan yield, its fucose and sulfate contents, and molecular weight (MW), while the investigated responses of the sequentially extracted alginate were yield, mannuronic/guluronic acid ratio (M/G) and MW. Under the optimized conditions, the fucoidan yield, fucose content, sulfate content, and MW were 6.55%, 21.01%, 30.92% and 7.12 × 103 Da, respectively, while alginate yield, M/G, and MW were 28.81%, 0.36, and 1.50 × 105 Da, respectively. The optimized products showed good Fe(III) chelating properties and the iron contents were 509.82 mg g?1 for fucoidan-Fe and 406.71 ± 5.18 mg g?1 for alginate-Fe. Under simulated gastrointestinal conditions, fucoidan-Fe and alginate-Fe complexes released 46 and 57% iron, respectively, which are nutritionally relevant amounts. Both fucoidan and alginate showed potent antioxidant properties, but their Fe complexes exhibited a reduced activity. The results of the present study indicated that citric acid could support the basis for an economical biorefinery process for the sequential extraction of fucoidan and alginate. Additionally, these polysaccharides could be good candidates for the preparations of iron supplements.

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6.
An edible marine red alga, Grateloupia filicina, collected from Jeju Island of Korea was hydrolyzed by cheap food-grade carbohydrases (Viscozyme, Celluclast, AMG, Termamyl, and Ultraflo) to investigate its anticoagulant activity. Among the tested enzymatic extracts of G. filicina, a Termamyl extract showed the highest anticoagulant activity. Anion-exchange chromatography on DEAE-cellulose and gelpermeation chromatography on Sepharose-4B were used to purify the active polysaccharide from the crude polysaccharide fraction of G. filicina. The purified sulfated polysaccharide (0.42 sulfate/total sugar) showed approximately 1,357 kDa molecular mass and was comprised mainly of galactose (98%) and 1-2% of glucose. The sample showed potential anticoagulant activity on activated partial thromboplastin time (APTT) and thrombin time (TT) assays. The purified G. filicina anticoagulant (GFA) inhibited the coagulation factor X (92%), factor II (82%), and factor VII (68%) of the coagulation cascade, and the molecular interaction (protein-polysaccharide) was highly enhanced in the presence of ATIII (antithrombin III). The dissociation constant of polysaccharide towards serine proteins decreased in the order of FXa (58.9 nM) >FIIa (74.6 nM) >FVII (109.3 nM). The low/less cytotoxicity of the polysaccharide benefits its use in the pharmaceutical industry; however, further studies that would help us to elucidate the mechanism of its activity are needed.  相似文献   

7.
The study of the structural bases of the biological properties of algal fucoidan (Ascophyllum nodosum) led us to look for enzymes able to modify this sulfated polysaccharide. In this context, we found a sulfoesterase activity in the digestive glands of the common marine mollusk Pecten maximus, which is active on fucoidan. This sulfoesterase activity was shown by capillary electrophoresis and 13C-1H NMR (500 MHz) analysis of the enzymatic hydrolysis of the fucoidan, of fucoidan oligosaccharides and of sulfated fucose isomers. We report the exhaustive list of all proton and carbon chemical shifts for each of the three isomers of sulfated-l-fucose (including of their alpha/beta anomers), i.e. the 2-O-, 3-O- and 4-O-sulfated fucose, which have been useful reference values for the assignments of NMR spectra of fucoidan oligosaccharides upon enzymatic desulfation. Our results demonstrated a high regioselectivity for this sulfoesterase, which hydrolyzes only the sulfate group at the 2-O position of the fucopyranoside. Therefore, this sulfoesterase is a helpful tool in the structure-activity study of the fucoidan, as the literature data suggest that the 2-O-sulfation level play a central role in the biological properties of the polysaccharide.  相似文献   

8.

Background

The polysaccharide of culture medium from Arthrospira platensis was extracted by ultrafiltration, partially characterized and assayed for anticoagulant activity.

Methods

The crude polysaccharidic fraction was fractionated by anion exchange chromatography on DEAE-cellulose, subjected to acetate cellulose electrophoresis and characterized by physicochemical procedures. The anticoagulant effect of the ultrafiltrated polysaccharide was checked by several coagulation tests.

Results

Anion exchange chromatography revealed in the whole ultrafiltrated polysaccharidic fraction the occurrence of a sulfated spirulan-like component designated PUF2. The average molecular weight of PUF2 was determined by size exclusion chromatography combined with multi-angle light scattering (SEC-MALS) and viscosimetry and was 199 kDa and the sulfate content was 20% weight/dry weight. The physicochemical characterization indicated the occurrence of rhamnose (49.7%), galacturonic and glucuronic acid (32% of total sugar). The anticoagulant effect of this sulfated polysaccharide was mainly due to the potentiation of thrombin inhibition by heparin cofactor II and was 4-times higher than that of the porcine dermatan sulfate whereas it had no effect on anti-Xa activity.

Conclusions

An ultrafiltrated sulfated polysaccharide, likely a calcium spirulan was obtained from the culture medium of A. platensis and showed an anticoagulant activity mediated by heparin cofactor II.

General significance

Old culture medium of A. platensis may represent an important source for the spirulan-like PUF2 which was endowed with potentially useful anticoagulant properties whereas its obtention by ultrafiltration may represent an extraction procedure of interest.  相似文献   

9.
Along with proteins, lipids, water and minerals, polysaccharides are the main chemical compounds of which macroalgae are built. Among the chemical compounds now widely examined is fucoidan (fucan, fucosan, sulfate fucan or sulfated fucan), a fucose-containing sulfated polysaccharide. Fucoidans isolated from different species have been extensively studied because of their varied biological properties, including anticoagulant and antitumor effects. Methodology based on mild acid hydrolysis can be used as an efficient tool to study the relationship between molecular weight of the sulfated polysaccharides and their biological activities. Anticancer activity of fucoidans can be significantly enhanced by lowering their molecular weight only when they are depolymerized under mild conditions. In this study, fucoidan was identified during extraction with H2SO4 and HCl; its presence was confirmed by FT-Raman spectroscopy in aqueous solution. In particular, shifts at 840 cm−1 were analysed, which are due to the presence of sulfate at the axial C-4 position, as were the shifts at about 811–809 cm−1, for which the sulfated fucoidan is responsible. Shifts of electrophoretic bands of fucoidan resulting from mild acid hydrolysis in H2SO4 and HCl were also analysed. The analytical procedure was developed using apparatus for cellulose acetate membrane electrophoresis and this was supplemented by semi-quantitative analysis.  相似文献   

10.
A natural lacquer polysaccharide with complex branches was separated into two fractions, LPH (MW 16.9x10(4)) and LPL (MW 6.85x10(4)). Results of 13C NMR and FT-IR indicated they had the same structure. The treatment of LPL with sodium periodate led to a partial cut-off of side chains with 4-O-methyl-D-glucuronic acid in the terminal. These polysaccharides were sulfated in the presence of Py*SO3/DMSO. Depending on the reaction conditions, the products showed a different degree of sulfation (DS) ranging from 0.57 to 1.57 and different molecular weights ranging from 1.71x10(4) to 3.49x10(4). FT-IR analysis showed the equatorial primary OH at O-6 and the axial secondary OH at O-4 were sulfated. Activated partial thromboplastin time (APTT), prothrombin time and thrombin time (TT) assays showed the sulfated polysaccharides could prolong APTT and TT, but not TP. These activities strongly depended on the DS, the molecular weights (MW) and the branching structure of polysaccharides. DS of above 0.8 was essential for anticoagulant activity. The anticoagulant activity increased with the DS and the molecular weights. The molecular weights played a more important role. The branching structure of polysaccharides increased the activities. In our studies, the sulfated polysaccharides with the DS of 1.15 and the highest MW of 3.49x10(4) had the best blood anticoagulant activities.  相似文献   

11.
sulfated polysaccharides from Durvillaea antarctica   总被引:2,自引:0,他引:2  
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12.
Sulfated polysaccharides (fucans and fucoidans) from brown algae show several biological activities, including anticoagulant and anti-inflammatory activities. We have extracted a sulfated heterofucan from the brown seaweed Lobophora variegata by proteolytic digestion, followed by acetone fractionation, molecular sieving, and ion-exchange chromatography. Chemical analyses and 13C-NMR and IR spectroscopy showed that this fucoidan is composed of fucose, galactose, and sulfate at molar ratios of 1:3:2. We compared the anticoagulant activity of L. variegata fucoidan with those of a commercial sulfated polysaccharide (also named fucoidan) from Fucus vesiculosus and heparin. The experimental inflammation models utilized in this work revealed that fucoidan from L. variegata inhibits leukocyte migration to the inflammation site. Ear swelling caused by croton oil was also inhibited when sulfated polysaccharides from F. vesiculosus and L. variegata were used. The precise mechanism of different action between homo-and heterofucans is not clear; nevertheless, the polysaccharides studied here may have therapeutic potential in inflammatory disorders. Published in Russian in Biokhimiya, 2008, Vol. 73, No. 9, pp. 1265–1273.  相似文献   

13.
Fucosylated chondroitin sulfate (FCScs) isolated from sea cucumber Cucumaria syracusana was characterized by Fourier Transform InfraRed spectroscopy (FT-IR), Nuclear Magnetic Resonance (NMR) spectroscopy and high performance size exclusion chromatograph, a multi-angle laser light scattering detector, a viscometer and a differential refractive index (dRI) detector (HPSEC-MALLS-dRI). The anticoagulant activities of FCScs were studied by the classical clotting time assays and the purified systems containing thrombin and antithrombin or heparin cofactor II. The effect on thrombin generation was investigated using calibrated automated thrombography (CAT). The results obtained showed that the FCS with high sulfate content 31 % and relatively low average molecular weight of 36.3 kDa was isolated from C. syracusana in amount of ∼ 35.6 mg/g dry body wall. Structural analysis of this polysaccharide revealed the presence backbone structure of chondroitin sulfate chain branched by two types of fucose 2,4-O-di and 3,4-O-disulfated residues in respective ratios of 57.5 and 42.5 %. The FCScs exhibited a high anticoagulant activity mediated essentially by heparin cofactor II (HCII) and to lesser extent by antithrombin (AT) with IC50 values of 0.05 μg/mL and 0.09 μg/mL, respectively. Furthermore, the results of CAT assay showed that the velocity index decreases 3-times at 50 μg/mL in comparison with normal plasma. The overall results showed high anticoagulant activity attributed to the high sulfate content and abundance of disulfated fucose branches of FCScs which made it a promising candidate of anticoagulation drug.  相似文献   

14.
Crude fucoidan was extracted from the brown alga Undaria pinnatifida collected monthly from April to last July in Peter the Great Bay (Japan Sea, Russia). The amount of crude fucoidan rose markedly from April to June–July (from 3.2 to 16.0% dry weight) as the plant matures. An analysis of the monosaccharide composition of the fucoidan extracted showed that the alga synthesized polysaccharides with various structures which were dependent on the algae age. In juvenile plants collected in April–May, this was represented by sulfated manno-galactofucan containing up to 19–28 mol% of mannose and about 20 mol% of galactose, whereas in matured plants collected in June–July, the polysaccharide was represented by a sulfated galactofucan containing more than 38 mol% galactose. It is postulated that the production of sori causes a subsequent effect on fucoidan synthesis and leads to an enhanced of crude fucoidan content and an increased molar concentration of galactose. Crude fucoidan content in sporophylls increased 5 times, and galactose content in this polysaccharide rose s1.6 times with sori formation. The structural characteristics of the fucoidan extracted from sporophylls of Undaria collected in July were also studied. The fractionation of crude fucoidan on DEAE-Sephadex A-25 gave two fractions, F1 and F2 in equal quantities. F1 was characterized as manno-galactofucan sulfate and F2 was galactofucan sulfate. The molecular weights of both fractions were in a range of 30–80 kDa. Analysis of fucoidan structure using ESI-FTICR mass spectrometry showed the presence of mixed oligosaccharides consisting of fucose and galactose. Presumably, the polysaccharide molecules contain blocks built up of successively linked residues of fucose and galactose. These blocks are built from two to five or more residues of monosaccharides. According to IR-spectroscopy data, the main portion of sulfates is located at C2; in addition, sulfate esters are also present at C4 on the fucose and C3 and C6 of the galactose units.  相似文献   

15.
褐藻多糖是海藻胶、褐藻糖胶和褐藻淀粉的统称,主要存在于褐藻中。褐藻糖胶作为其主要的生理活性物质,主要由L-岩藻糖和硫酸酯基组成,具有抗氧化、抗凝血、防癌抗肿瘤、抗病毒和消炎等活性。综述了褐藻多糖的提取分离方法和褐藻糖胶的生理活性研究进展,以期为褐藻多糖的应用提供参考。  相似文献   

16.
A study of fucoidan from the brown seaweed Chorda filum.   总被引:9,自引:0,他引:9  
Fucoidan fractions from the brown seaweed Chorda filum were studied using solvolytic desulfation. Methylation analysis and NMR spectroscopy were applied for native and desulfated polysaccharides. Homofucan sulfate from C. filum was shown to contain poly-alpha-(1-->3)-fucopyranoside backbone with a high degree of branching, mainly of alpha-(1-->2)-linked single units. Some fucopyranose residues are sulfated at O-4 (mainly) and O-2 positions. Some alpha-(1-->3)-linked fucose residues were shown by NMR to be 2-O-acetylated. The 1H and 13C NMR spectra of desulfated, deacetylated fucan were completely assigned. The spectral data obtained correspond to a quasiregular polysaccharide structure with a branched hexasaccharide repeating unit. Other fucoidan fractions from C. filum have more complex carbohydrate composition and give rather complex methylation patterns. [formula: see text]  相似文献   

17.
Brown seaweed contains several polysaccharides like laminaran, fucoidan and alginate. Laminaran is a β-glucan that has shown anti-apoptotic and anti-tumoral activities, while galactofucan (fucoidan) is a sulfated polysaccharide that has displayed anticoagulant, anti-tumor, anti-thrombosis, anti-inflammatory and antiviral properties. In this study, crude laminaran and galactofucan (fucoidan) were extracted from the brown seaweed Saccharina longicruris at four harvest periods (M05, A05, N05 and J06). The galactofucan M05 and N05 fractions were depolymerized (RDP) over 2 or 4 h to give 4 RDP fractions (M05 RDP 2H, M05 RDP 4H, N05 RDP 2H and N05 RDP 4H) whose molecular weights, monosaccharide compositions and glycosidic linkages were determined by GC-MS. The laminaran fraction gave a molecular weight range from 2900 to 3300 Da and contained between 50.6% and 68.6% d-glucose and an average of 1.3% d-mannitol. The presence of a β-(1,3) linkage between d-glucose in the main chain was observed, with branching at positions 6 and 2. The M05 fraction contained less branching than other laminaran fractions, which might have influenced its conformation in solution and thus its activity. The crude galactofucan fractions displayed a molecular weight range from 638 to 1529 kDa, whereas the RDP fractions had molecular weights <30 kDa. The structure of the galactofucan fractions remained complex after depolymerization, with these also being more sulfated (30-39%) than the crude fractions (13-20%). The crude and RDP fractions contained 3-linked fucopyranose 4-sulfate and 6-linked galactopyranose 3-sulfate moieties, although the galactofucans isolated from M05 and J06 contained less 6-linked galactopyranose 3-sulfate than the A05 and N05 fractions.  相似文献   

18.
A fucoidan fraction composed of l-fucose, sulfate, and d-glucuronic acid in a molar proportion of about 1:1:0.25 and small amount of acetyl groups was isolated from the brown alga Chordaria flagelliformis. Several modified polysaccharides were prepared from the native fucoidan using solvolytic desulfation, carboxyl reduction, and partial acid hydrolysis. Polysaccharide structures were elucidated by methylation analysis and 1D and 2D NMR spectroscopy. The fucoidan was shown to contain a backbone of 3-linked α-l-fucopyranose residues, about one-third of which are glycosylated at C-2 by α-d-glucopyranosyluronic acid residues. About half of the latter residues are glycosylated at C-4 by single α-l-fucofuranose residues or by disaccharides α-l-Fucf-(1→2)-α-l-Fucf-(1→. Fucofuranose residues are mono- and disulfated at different positions, whereas some additional sulfate groups occupy C-2 and C-4 of the backbone, the latter position being also partially acetylated.  相似文献   

19.
The composition, molecular weight (MW), anticoagulant activity and nuclear magnetic resonance spectra of various low-molecular-weight fucans (LMWFs) obtained by partial hydrolysis or radical depolymerization of a crude fucoidan extracted from the brown seaweed Ascophyllum nodosum are compared. Fucose units were found mainly sulfated at O-2, to a lesser extent at O-3, and only slightly at O-4, contrary to previously published results for fucoidans from other brown seaweeds, and fucose 2, 3-O-disulfate residues were observed for the first time. As the sulfation pattern excluded an alpha-(1-->2)-linked fucose backbone and a high proportion of alpha-(1-->4) linkages was found, it would appear that the concept of fucoidan structure needs to be revised. Anticoagulant activity is apparently related not only to MW and sulfation content, as previously determined, but also (and more precisely) to 2-O-sulfation and 2,3-O-disulfation levels.  相似文献   

20.
The pharmacological properties of unfractionated dermatan sulfate (U-DS, mean MW 25 kd, range 12-45 kd) of a low molecular weight fraction (LMW-DS, mean MW 4 kd range 1.6-8 kd), and of 2 oversulfated derivatives (S-DS1 and S-DS2, 2 and 3.8 sulfate groups per disaccharide units) were investigated. In a purified system, LMW-DS, S-DS1 and S-DS2 were respectively 0.5, 10 and 17 times more potent than U-DS to catalyse thrombin inhibition by heparin cofactor II. Identical differences were observed for the respective anticoagulant activities (activated partial thromboplastin time and thrombin clotting time). After bolus IV injection of increasing doses the pharmacokinetic parameters of U-DS were slightly dose dependent, and the total clearance of LMW-DS was, on the average, 2 times higher. The patterns of disappearance of S-DS1 and S-DS2 were strongly dose dependent and became concave-convex, suggesting different mechanisms of clearance. After SC injection, the bioavailability was less than 50% for U-DS and at least 100% for LMW-DS. The antithrombotic activity (Wessler-thromboplastin model) of LMW-DS was 2 timer lower than that of U-DS. In contrast to their in vitro (and ex vivo) enhanced anticoagulant activities, the antithrombotic potency of S-DS1 was identical to that of U-DS, while, at the same doses S-DS2 was devoid of any activity.  相似文献   

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