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1.
Fucoidan, a group of sulfated heteropolysaccharides, was extracted from Laminaria japonica, an important economic alga species in China. The anticoagulant activity of fucoidan and its derivatives (including sulfated, phosphorylated, and aminated fucoidan) was examined using in-vitro anticoagulant systems. The correlation between chemical variations within the fucoidan group and anticoagulant activity was determined. The in-vitro anticoagulant properties of fucoidan and its derivatives were determined by measuring activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT). The results indicate anticoagulant activity in all samples using APTT and TT assays; however, only the fucoidan derivatives affected the PT assay. Thus, the fucoidan derivatives were able to inhibit both intrinsic and extrinsic blood coagulants. Fucoidan (FPS) and its derivatives presented better anticoagulant activity than low molecular weight fucoidan (DFPS) and its derivatives, suggesting that molecular weight and proper conformation are contributing factors for anticoagulant activity of polysaccharides. Amino groups have a positive charge and can thus change the charge density of fucoidan. Accordingly, among the tested samples, aminated fucoidan (NF) was the most active reflecting the importance of charge density for anticoagulant activity. Available data obtained using in-vitro models suggest that the sulfate content, sulfate/total-sugar ratio, molecular weight, and the substituted group of fucoidan are important factors for anticoagulant activity but that the influence of sulfate, phosphate and amino groups on anticoagulant activity was different.  相似文献   

2.
Cardiovascular disease is the leading causes of death.However,the complications can be treated with heparin and heparinoids,such as heparin pentasaccharide Fondaparinux,dermatan sulfate,and PSS made from alginate extracted from brown seaweeds by chemical sulfation.Alginate is composed of a linear backbone of polymannuronate(PM),polyguluronate(PG),and alternate residues of mannuronic acid and guluronic acid.It is unknown if heparin and sulfated PG(PGS)/PM(PMS) have the same or different anticoagulant molecular targets.In the current study,the anticoagulant activities of PGS,PMS,and their oligosaccharides were directly compared to that of heparin,Fondaparinux,and dermatan sulfate by the activated partial thrombinplastin time(aP TT) assay using normal,antithrombin III(ATIII)-deficient,heparin co-factor II(HCII)-deficient,and ATIII-and HCII-double deficient human plasmas.Our results showed that PGS,PMS,and their oligosaccharides had better anticoagulant activity than that of Fondaparinux in all four human plasmas tested.As expected,heparin was the best anticoagulant in normal plasma.Moreover,PGS,PGS6,PGS12,PGS25,PMS6,PMS12,and PMS25 were better anticoagulants than dermatan sulfate in HCII-deficient plasma.Most strikingly,PGS,PGS12,PGS25,PMS6,PMS12,and PMS25 were better anticoagulants than that of heparin in ATIII-and HCII-double deficient human plasma.The results revealed for the first time that sulfated alginate had ATIII-and HCII-independent anticoagulant activities.Therefore,developing PGS and PMS-based anticoagulants might require to discover their major molecular targets and to develop target-specific anticoagulant assays.  相似文献   

3.
To explore the polysaccharides from selected seaweeds of Atlantic Canada and to evaluate their potential anti-influenza virus activities, polysaccharides were isolated from several Atlantic Canadian seaweeds, including three red algae (Polysiphonia lanosa, Furcellaria lumbricalis, and Palmaria palmata), two brown algae (Ascophyllum nodosum and Fucus vesiculosus), and one green alga (Ulva lactuca) by sequential extraction with cold water, hot water, and alkali solutions. These polysaccharides were ana-lyzed for monosaccharide composition and other general chemical properties, and they were evaluated for anti-influenza virus activities. Total sugar contents in these polysaccharides ranged from 15.4% (in U. lactuca) to 91.4% (in F. lumbricalis); sulfation level was as high as 17.6% in a polysaccharide from U. lactuca, whereas it could not be detected in an alikali-extract from P. palmaria. For polysaccharides from red seaweeds, the main sugar units were sulfated galactans (agar or carrageenan) for P. lanosa, F. lumbricalis, and xylans for P. palmata. In brown seaweeds, the polysaccharides largely contained sulfated fucans, whereas the polysaccharides in green seaweed were mainly composed of heteroglycuronans. Screening for antiviral activity against influenza A/PR/8/34 (H1N1) virus revealed that brown algal polysaccharides were particularly effective. Seaweeds from Atlantic Canada are a good source of marine polysaccharides with potential antiviral properties.  相似文献   

4.
The antithrombotic and antiplatelet effects of two fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica were compared in order to examine the influence of chemical character on their antithrombotic activity and the possible mechanism. Both LMW fucoidan fractions exhibited favorable antithrombotic activity in an Fecl3-induced arterial thrombosis. The antithrombotic activity of LMW fucoidan was related with decrease of TXB2 and whole blood viscosity and hematocrit. LMW fucoidan showed a correlation between anticoagulant, antiaggregant and antithrombotic effects in vivo. For LMW fucoidan, antithrombotic activity required high dose of 5-10 nmol kg-1, concomitantly with increase in anticoagulant activity and inhibition of platelet aggregation. Administration of LMW fucoidan significantly promoted the 6-keto-PGF1α content and decreased the TXB2 content, indicating its inhibition of tissue factor pathway and regulation of metabolism of arachidonic acid. By comparison, highly sulfated fucoidan LF2 with Mw 3900 seemed to be a more suitable choice for antithrombotic drug for its antithrombotic activity accompanied with specific inhibitory activity on platelet aggregation, low anticoagulant activity and low hemorrhagic risk in vivo.  相似文献   

5.
As molecular weight controls the biological activities of polysaccharides, screening the optimal molecular weight of polysaccharides is important in drug research and application. In this study, hydrogen peroxide was employed as oxidant, and temperature, reaction time, and concentration of polysaccharides and hydrogen peroxide were examined for their effects on the preparation of polysaccharides in different molecular weights fromUlva pertusa. Our experiment suggested that the optimal degradation concentrations for polysaccharides and hydrogen peroxide were 2.5% (w/v) and 8.0% (v/v), respectively. The range of degradation measured by relative viscosity was mainly controlled by temperature and time. Results revealed that 35°C was the optimal temperature for obtaining low-degradation samples, and 50°C was the most favorable temperature to accelerate the reaction to yield highly-degraded samples. Four samples in different molecular weights A, B, C and D were finally prepared. The controllability was evaluated by the relative standard deviation (RSD) of relative viscosity, and the peak molecular weights and the polydispersity indexes (Mw/Mn) of molecular weights were measured by high performance gel permeation chromatography (HPGPC). This work was supported by the Scientific and Technical Bureau of Shandong Province.  相似文献   

6.
Brown alga （ Undaria pinnatifida） was treated with alginate lyase and hydrolyzed using 17 kinds of proteases and the inhibitory activity of the hydrolysates for the angiotensin-I-converting enzyme （ACE） was measured. Four hydrolysates with potent ACE-inhibitory activity were administered singly and orally to spontaneously hypertensive rats （SHRs）. The systolic blood pressure of SHRs decreases significantly after single oral administration of the brown alga hydrolysates by pro- tease S ＇ Amano＇ （from Bacillus stearothermophilus） at the concentration of 10 （mg protein） （kg body weight）^ - 1. In the 17 weeks of feeding experiment, 7-week-old SHRs were fed standard diet supplemented with the brown alga hydrolysates for 10 weeks. In SHRs fed 1.0 and 0.1% brown alga hydrolysates, elevating of systolic bloodpressure was significantly suppressed for 7 weeks. To elucidate the active components, the brown alga hydrolysates were fractionated by 1-butanol extraction and HPLC on a reverse-phase column. Seven kinds of ACE-inhibitory peptides were isolated and identified by amino acid composition analysis, sequence analysis, and LC-MS with the results Val-Tyr, Ile-Tyr, Ala-Trp, Phe-Tyr, Val-Trp, Ile-Trp, and Leu-Trp. Each peptide was determined to have an antihypertensive effect after a single oral administration in SHRs. The brown alga hydrolysates were also confirmed to decrease the blood pressure in humans.  相似文献   

7.
Results of a series of experiments(on the adsorption of divalent metal ions by dried alginic acid, Na and Ca alginates of different composition and block structure) conducted in this systematic study of the effects of the composition and structure of alginates on the static adsorption equilibrium of divalent metal ions indicate that the properties of alginate adsorption to divalent metal ions are highly different, depending not only on the cations used, but also on the form and structure of the alginates. There is close correlation between the adsorption properties and the structure of the alginates. The selectivity coefficient of Na alginate for Cd-Sr ion exchange tends to increase with the increase of the M/G ratio in alginate, whereas the adsorption capacity of Ca alginate for Cu~(2+) ion decrease with the increase of the G-block or the average length of the G-block ((?)_G) and the total adsorption capacity of alginic acid is found to vary in the same order as the F_(MM)(diad frequency) in alginate in  相似文献   

8.
1 IntroductionIncreased blood pressure appears to be one of theprimary risk factors of circulatory organ diseases suchas encepharo-apoplexy, encepharo-infarction and cardi-ac infraction. Angiotensin-I-converting enzyme (ACE)plays an important role in the rennin-angiotensin sys-tem by regulating blood pressure. Antihypertensivedrugs such as captopril and enalapril are potent ACEinhibitors (Ondetti et al., 1977). Recently, severalinhibitory peptides derived from food proteins havebeen isolat…  相似文献   

9.
Results of a series of experiments (on the adsorption of divalent metal ions by dried alginic acid, Na and Ca alginates of different composition and block structure) conducted in this systematic study of the effects of the composition and structure of alginates on the static adsorption equilibrium of divalent metal ions indicate that the properties of alginate adsorption to divalent metal ions are highly different, depending not only on the cations used, but also on the form and structure of the alginates. There is close correlation between the adsorption properties and the structure of the alginates. The selectivity coefficient of Na alginate for Cd-Sr ion exchange tends to increase with the increase of theM/G ratio in alginate, whereas the adsorption capacity of Ca alginate for Cu2+ ion decrease with the increase of the G-block or the average length of the G-block and the total adsorption capacity of alginic acid is found to vary in the same order as theF MM(diad frequency) in alginate in the mixed solution of Sr2+, Ba2+ and Cd2+. Contribution No. 2166 from the Institute of Oceanology, Chinese Academy of Sciences.  相似文献   

10.
Several studies have indicated that fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica could inhibit the activation of platelets directly by reducing the platelet aggregation. To explore the direct effect of LMW fucoidan on the platelet system furthermore and examine the possible mechanism, the endothelial protection and inhibits platelet activation effects of two LMW fucoidan were investigated. In the present study, Endothelial injury model of rats was made by injection of adrenaline(0.4 mg kg-1) and human umbilical vein endothelial cells were cultured. v WF level was be investigated in vivo and in vitro as an important index of endothelial injury. LMW fucoidan could significantly reduce v WF level in vascular endothelial injury rats and also significantly reduce v WF level in vitro. The number of EMPs was be detected as another important index of endothelial injury. The results showed that LMW fucoidan reduced EMPs stimulated by tumor necrosis factor. In this study, it was found that by inhibiting platelet adhesion, LMW fucoidan played a role in anti-thrombosis and the specific mechanism of action is to inhibit the flow of extracellular Ca2+. All in a word, LMW fucoidan could inhibit the activation of platelets indirectly by reducing the concentration of EMPs and v WF, at the same time; LMW fucoidan inhibited the activation of platelets directly by inhibiting the flow of extracellular Ca2+.  相似文献   

11.
Carbohydrases secreted by marine Vibrio sp. YKW-34 with strong Laminaria cell wall degrading ability were screened, and among them alginate lyase was found to be dominant. The effects of medium composition and culturing condition on the production of alginate lyase by marine Vibrio sp. YKW-34 in flask were investigated in this study. In the culture medium of marine broth, no alginate lyase was produced. The activity of the alginate lyase, after being induced, reached 5 UmL^-1. The best inoculum volume and inoculum age were 10% and 12h, respectively. The optimal temperature for alginate lyase production was 25℃. The fermentation medium was composed of 0.5% of Laminaria powder and 0.2% of KNO3 with an initial acidity of pH 8.0. Alginate could induce alginate lyase production but not as efficiently as Laminaria powder did. The addition of fucoidan, cellulose and glucose had negative effect on the alginate lyase production. Other kinds of nitrogen sources, such as yeast extract, beef extract and peptone, had positive effect on the growth of the microorganism and negative effect on alginate lyase production. In addition, the time course of alginate lyase production under the optimized condition was described. The optimal harvest time was 48 h.  相似文献   

12.
Fucoidan is such a polysaccharide that its hydroxies are easy to combine with lanthanons ion (CeⅣ) to form complex. This work obtained the complexes of three fucoidan oligosaccharides with different molecular weights F1( ＞5 000), F2(1 000-5 000) and F3( ＜ 1 000) by hydrolyzing Oligosaccharide collagen with sulfuric acid. It is found that the fucoidan oligosaccharide F3 can form complex with more CeⅣ than F1 and F2. Hydrolyzing collagen with the complex was carried out to produce amino acid and peptides. All the three fucoidan oligosaccharide complexes with CeⅣ( F1, F2, F3) can catalyze by the artificial hydrolytic enzyme, and the activity of the complex of F3 is the highest.  相似文献   

13.
Fucoidan is such a polysaccharide that its hydroxies are easy to combine with lanthanons ion (CeIV) to form complex. This work obtained the complexes of three fucoidan oligosaccharides with different molecular weights F1(>5000), F2 (1000-5000) and F3(<1000) by hydrolyzing Oligosaccharide collagen with sulfuric acid. It is found that the fucoidan oligosaccharide F3 can form complex with more CeIV than F1 and F2. Hydrolyzing collagen with the complex was carried out to produce amino acid and peptides. All the three fucoidan oligosaccharide complexes with CeIV( F1, F2, F3) can catalyze by the artificial hydrolytic enzyme, and the activity of the complex of F3 is the highest.  相似文献   

14.
Fucoidan, a polysaccharide containing abundant fucose and sulfate ester group, was prepared from Laminaria japonica. In order to obtain fucoidan-degrading enzyme, bacteria capable of degrading fucoidan were screened from kelp. A bacterial strain named RC2-3 was obtained, which degraded fucoidan by the maximum extent of 54% ± 1.3%, the highest among all bacterial isolates. High-performance size exclusion chromatography(HPSEC) showed that the molecular weight of fucoidan was gradually reduced by RC2-3 with culturing time, suggesting the production of fucoidan-degrading enzyme by RC2-3. Phylogenetic analysis of partial 16S ribosomal RNA gene(16S rDNA) sequence showed that RC2-3 belonged to the family Flavobacteriaceae. However, it showed different physiological and biochemical characteristics from the known Flavobacteriaceae members producing fucoidan-degrading enzyme, thus RC2-3 was proposed to be a new member of this family.  相似文献   

15.
南海3种可食绿藻化学成分及其营养评价   总被引：4，自引：0，他引：4  
对南海3种可食绿藻条浒苔(Enterom orpha clathrata)、石莼(Ulva lactucaL.)和总状蕨藻(Caulerpa racem o-sa)的主要化学成分进行了分析,结果显示:多糖、蛋白质和粗纤维是构成藻体的主要化学成分,占藻体的92%以上,其中膳食纤维占64.22%~70.80%;蛋白质占14.15%~18.91%,平均为16.16%,且蛋白质中必需氨基酸含量高,占总氨基酸的42.37%~48.37%,氨基酸评分在73分以上,第一限制氨基酸随藻种而变化;脂肪含量在0.51%~0.81%之间,均低于1%,多不饱和脂肪酸和必需脂肪酸含量高,其含量分别为其总量的56.10%~63.20%和37.71%~39.39%;矿物质和维生素含量丰富,尤其是Fe、Zn、I等矿质元素和维生素C含量高。3种可食绿藻是高膳食纤维,高蛋白,低脂肪,低热能,且富含矿物质和维生素的天然理想保健食品原料。  相似文献   

16.
Three kinds of polysaccharides:GFW,GFH and GFA,were sequentially extracted from a red alga Gloiopeltis furcatawith 25℃and 85℃water,and 60℃ 4%NaOHwater solution.Based on the defatted alga,the yields of the polysaccharide were57.9%,2.5%and 2.6%,respectively.Their monosaccharide compositions,average molecular weights and structural characters weredetermined by gas chromatography(GC),high performance liquid chromatography(HPLC),fourier transform infrared spectroscopy(FTIR)or13C-NMR spectroscopy.The results show...  相似文献   

17.
ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｒｅｃｅｎｔｙｅａｒｓ,ｃｏ ｃｕｌｔｕｒｅ (ｉｎｔｅｇｒａｔｅｄｃｕｌｔｕｒｅ )ｏｆｍａｒｉｎｅｓｐｅｃｉｅｓ (ａｌｇａｅａｎｄａｎｉｍａｌｓ)ｈａｓｒｅｃｅｉｖｅｄｇｒｅａｔａｔｔｅｎｔｉｏｎ .Ｉｎｃｏ ｃｕｌｔｕｒｅｓｙｓｔｅｍｔｈｅａｌｇａｅａｃｔｉｖｅｌｙｕｐｔａｋｅＣＯ2 ａｎｄｔｈｅｍｅｔａｂｏｌｉｃｗａｓｔｅｓ(ｓｕｃｈａｓＮＨ4 +,ＮＯ2 - ,ＮＯ3- ｅｔｃ)ａｓｎｕｔｒｉｅｎｔｓｏｕｒｃｅｓ,ａｎｄｒｅｌｅａｓｅＯ2 ｔｏｔｈｅｓｕｒｒｏｕｎｄｉｎｇｅｎｖｉｒｏｎ …  相似文献   

18.
The species composition, horizontal distribution and seasonal succession of the phyto-plankton at five sampling stations in the channel between Dongting Lake and the Changjiang River, China were studied from May 1995 to December 1997. A total of 416 taxa were observed; diatoms comprised the most diverse taxonomic group representing 58.2 % of the total species. The β-mezotrophic indicators were 92 taxa or 22 % of the total, the a-mezotrophic or α, β-eutrophic indicators decreased distinctly to 20 taxa or 4.8 % of the total. The species number and composition of various phyla were approximately similar at Stations 1, 2, 3 and 4, but at Station 5 the number of species was the minimum and the ratio of diatoms to total phytoplankton in the number of species was the highest. In seasonal succession of the phytoplank-ton species, the number was the highest in May and June, lower in December, January, March and July in the channel. The dominant species were different in different months. The ratio of diatoms species number to blue green algae and green algae species number diminished gradually from winter to summer and autumn, and then increased gradually from autumn to winter and early spring in the annual cycle. Margalef, Simpson and Shannon—Weaver diversity indices changed in different months, their values were higher in winter, lower in summer. Nygaard‘s diatoms quotients were lower in winter, then in spring and autumn, higher in summer. These results indicated that the water quality was the best in winter, better in spring and autumn than in summer. The relationship between the structure of the phytoplankton communi-ty and the water environmental quality was discussed.  相似文献   

19.
Water-soluble algal polysaccharides (APS) (alginic acid, fucoidan and laminaran) possess many pharmacological activities. The results of this study showed that the APS-Ce^4 complexes have some enzyme-like activities. Fucoidan and its complex with Ce^4 have activities similar to those of SOD. The activities of laminaran, alginic acid and their complexes are not measurable. The APS do not show measurable activities in the digestion of plasmid DNA. In contrast, the APS - Ce^4 complexes show these measurable activities under the comparable condition when APS bind Ce^4 and form homogenous solutions. The laminaran-Ce^4 complex shows the most obvious activity in the digestion of plasmid DNA, pNPP and chloropyrifos under neutral conditions.  相似文献   

20.
对南海长松藻(Codium cylindricum Holmes)的主要营养成分进行了分析,结果显示:多糖、蛋白质和粗纤维是构成藻体的主要营养成分,占藻体干基的80%左右,其中多糖占55.57%、粗纤维占11.09%、蛋白质占12.57%,但脂肪含量仅为0.59%。水溶性营养成分较为丰富,水浸出物总量为34.55%,其中包括水溶性蛋白、水溶性多糖、游离氨基酸等。多糖是长松藻的主要有效成分。单因素及正交实验结果表明:长松藻多糖提取的最佳工艺参数为浸提温度95℃,浸提时间1.5 h,料水质量比1∶50,多糖得率为9.79%。  相似文献   

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