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Marc Lahaye - One of the best experts on this subject based on the ideXlab platform.
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determination of the chemical composition of Ulvan a cell wall polysaccharide from ulva spp ulvales chlorophyta by ft ir and chemometrics
Journal of Applied Phycology, 2009Co-Authors: Yannick Lerat, Annie Robic, Jean-francois Sassi, Dominique Bertrand, Marc LahayeAbstract:The water-soluble cell wall polysaccharides from green seaweeds of Ulva spp. (Ulvales, Chlorophyta), referred to as Ulvan, demonstrate composition- and structure-related functional properties. Mid-infrared spectroscopy combined with chemometric techniques was investigated as a means to rapidly predict the chemical composition of Ulvan extracts. A calibration was realized with 41 Ulvan extracts from two Ulva species. The variables studied included the constituent sugars (rhamnose, xylose, glucose, galactose, glucuronic acid, iduronic acid), protein, and sulfate contents. The correlation between Fourier transform infrared and chemical data was developed using partial least squares (PLS) regression with full cross-validation (leave one out). The coefficients of determination in cross-validation (\(R_{{\text{CAL}}}^2 \)) and the standard error in cross-validation were determined for each variable. The PLS model validation resulted in a coefficient of determination (\(R_{{\text{VAL}}}^2 \)) and a standard error in prediction. Good predictions were obtained for rhamnose (\(R_{{\text{VAL}}}^2 \) = 0.9244), xylose (\(R_{{\text{VAL}}}^2 \) = 0.8758), glucuronic acid (\(R_{{\text{VAL}}}^2 \) = 0.9415), and sulfate (\(R_{{\text{VAL}}}^2 \) = 0.9218), which are the main Ulvan constituents. However, minor components such as proteins, glucose, galactose, and iduronic acid were not correctly predicted. This study showed that mid-infrared spectroscopy combined with PLS regression is a reliable and fast method for the quantification of the main chemical constituents of Ulvan extracts.
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structure and interactions of Ulvan in the cell wall of the marine green algae ulva rotundata ulvales chlorophyceae
Carbohydrate Polymers, 2009Co-Authors: Annie Robic, Yannick Lerat, Jean-francois Sassi, Corinne Rondeaumouro, Marc LahayeAbstract:Abstract Ulvan, the sulfated cell-wall polysaccharides from green seaweeds ( Ulva species), presents structural and functional properties of interest for different applications. Its extraction yield in water varies depending on the species, the period of collect and the mode of conservation of algae. To identify limits of extraction, the structure and interactions of Ulvan in the cell wall of Ulva were investigated following a sequential solvent extraction. Hot sodium oxalate and hot dilute HCl were the two major extracts. Other solvents affecting protein structure or low hydrogen bonded polymers yielded minor Ulvan fractions but affected solid state 13 C NMR spectra indicating that proteins likely contributed to cross-link and/or to entrap Ulva cell wall polysaccharides. Ulvan-lyase degradation showed that Ulvan consisted in a wide continuum of related polysaccharides differing in the extent and type of fine structural characteristics. Besides solvent acidity, particle size of seaweeds was an important parameter controlling the Ulvan extraction efficiency. Major Ulvan cell wall interactions were discussed with regard to ionic interactions, covalent linkages and peculiar solution behavior of Ulvan in various physicochemical environments.
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impact of stabilization treatments of the green seaweed ulva rotundata chlorophyta on the extraction yield the physico chemical and rheological properties of Ulvan
Carbohydrate Polymers, 2008Co-Authors: Annie Robic, Jean-francois Sassi, Marc LahayeAbstract:Abstract The impact of freezing, freeze-drying, hot-air drying, brining and dry salting stabilization methods of Ulva rotundata has been studied on the yield, physico-chemical characteristics and rheological properties of Ulvan. Frozen (−30 and −80 °C) and freeze-dried algae yielded Ulvan extracts mainly composed of high molecular weight polysaccharides. These had the highest intrinsic viscosity and conservation modulus (G′) as copper/borate gels compared to Ulvan from fresh algae (taken as a reference) or Ulvan extracted from algae stabilized by other means. Cold stabilizations of algae yielded the lowest amounts of Ulvan. High Ulvan yields were obtained from Ulva air-dried at 50 and 70 °C but that at 50 °C was lower than that at 70 °C. Gelling properties and intrinsic viscosities from these Ulvans were better than that of fresh algae but lower than from cold treated seaweeds. Brining induced Ulvan degradation with poor rheological properties of the extracts compared to Ulvan from fresh algae. However, this process appears to ease extraction of polysaccharides. Compared to fresh algae, salted seaweeds stored at room temperature yielded degraded Ulvan. Decreasing the salting process temperature to 4 °C preserved Ulvan composition, structure and properties. However, Ulva salting hinders drastically Ulvan extraction. The different stabilization processes affected the chemical composition of Ulvan extracts and in particular, sulphate and protein contents. The results show that different stabilization conditions of Ulva biomass can be selected according to their cost-effectiveness and the required Ulvan chemical and macromolecular characteristics.
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Structure and functional properties of Ulvan, a polysaccharide from green seaweeds
Biomacromolecules, 2007Co-Authors: Marc Lahaye, Audrey Robic, . Biopolymères, Interactions AssemblagesAbstract:With today's interest in novel renewable chemicals and polymers, the underexploited marine green algae belonging to species of Ulva and Entermorpha stimulated interest as sources of polysaccharides with innovative structure and functional properties. These algae are common on all seashores and can produce in time an important amount of biomass in nutrient-enriched waters. The major water-soluble polysaccharide, Ulvan, extracted from the cell wall represents about 8-29% of the algae dry weight. The original physicochemical, rheological, and biological properties recently unraveled for this complex sulfated aldobiouronan open the way for novel potential applications.
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Chemical composition and 13C NMR spectroscopic characterisation of Ulvans from Ulva (Ulvales, Chlorophyta)
Journal of Applied Phycology, 1999Co-Authors: Marc Lahaye, Enrique Alvarez-cabal Cimadevilla, Ralph Kuhlenkamp, Bernard Quemener, Vincent Lognoné, Patrick DionAbstract:The chemical composition and structures of several Ulvan extracts isolated from various Ulva species were studied. They were all composed mainly of rhamnose, glucuronic acid, xylose, glucose and sulphate with smaller amounts of iduronic acid and traces of galactose. Proteins were also present, most likely as contaminants. Precise quantification of the uronic acid content by chemical-enzymatic hydrolysis coupled to HPAEC-PAD analysis and by colorimetry was not achieved, most likely due to the incomplete hydrolysis of glucuronan segments, inadequate HPAEC-pulsed-amperometric response factor for iduronic acid and to a possible differential colorimetric response of the two uronic acids. ^13C NMR spectroscopic investigation of different Ulvans demonstrated that they were all based on Ulvanobiuronic acid 3-sulphate A and B repeating units [β-D-Glc pA-(1->4)-α-L-Rhap3S and α-L-IdopA-(1->4)-α-L-Rha p3S, respectively] as well as contiguous β 1->4 linked D-glucuronic acids possibly occurring either in Ulvan or as a separate glucuronan. Marked variations in the content of the repeating structures were seen among the different samples. However, due to the limited number of samples studied, no conclusion was reached concerning the effects of species and ecophysiological conditions on the chemistry of Ulvan.
Annie Robic - One of the best experts on this subject based on the ideXlab platform.
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determination of the chemical composition of Ulvan a cell wall polysaccharide from ulva spp ulvales chlorophyta by ft ir and chemometrics
Journal of Applied Phycology, 2009Co-Authors: Yannick Lerat, Annie Robic, Jean-francois Sassi, Dominique Bertrand, Marc LahayeAbstract:The water-soluble cell wall polysaccharides from green seaweeds of Ulva spp. (Ulvales, Chlorophyta), referred to as Ulvan, demonstrate composition- and structure-related functional properties. Mid-infrared spectroscopy combined with chemometric techniques was investigated as a means to rapidly predict the chemical composition of Ulvan extracts. A calibration was realized with 41 Ulvan extracts from two Ulva species. The variables studied included the constituent sugars (rhamnose, xylose, glucose, galactose, glucuronic acid, iduronic acid), protein, and sulfate contents. The correlation between Fourier transform infrared and chemical data was developed using partial least squares (PLS) regression with full cross-validation (leave one out). The coefficients of determination in cross-validation (\(R_{{\text{CAL}}}^2 \)) and the standard error in cross-validation were determined for each variable. The PLS model validation resulted in a coefficient of determination (\(R_{{\text{VAL}}}^2 \)) and a standard error in prediction. Good predictions were obtained for rhamnose (\(R_{{\text{VAL}}}^2 \) = 0.9244), xylose (\(R_{{\text{VAL}}}^2 \) = 0.8758), glucuronic acid (\(R_{{\text{VAL}}}^2 \) = 0.9415), and sulfate (\(R_{{\text{VAL}}}^2 \) = 0.9218), which are the main Ulvan constituents. However, minor components such as proteins, glucose, galactose, and iduronic acid were not correctly predicted. This study showed that mid-infrared spectroscopy combined with PLS regression is a reliable and fast method for the quantification of the main chemical constituents of Ulvan extracts.
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structure and interactions of Ulvan in the cell wall of the marine green algae ulva rotundata ulvales chlorophyceae
Carbohydrate Polymers, 2009Co-Authors: Annie Robic, Yannick Lerat, Jean-francois Sassi, Corinne Rondeaumouro, Marc LahayeAbstract:Abstract Ulvan, the sulfated cell-wall polysaccharides from green seaweeds ( Ulva species), presents structural and functional properties of interest for different applications. Its extraction yield in water varies depending on the species, the period of collect and the mode of conservation of algae. To identify limits of extraction, the structure and interactions of Ulvan in the cell wall of Ulva were investigated following a sequential solvent extraction. Hot sodium oxalate and hot dilute HCl were the two major extracts. Other solvents affecting protein structure or low hydrogen bonded polymers yielded minor Ulvan fractions but affected solid state 13 C NMR spectra indicating that proteins likely contributed to cross-link and/or to entrap Ulva cell wall polysaccharides. Ulvan-lyase degradation showed that Ulvan consisted in a wide continuum of related polysaccharides differing in the extent and type of fine structural characteristics. Besides solvent acidity, particle size of seaweeds was an important parameter controlling the Ulvan extraction efficiency. Major Ulvan cell wall interactions were discussed with regard to ionic interactions, covalent linkages and peculiar solution behavior of Ulvan in various physicochemical environments.
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impact of stabilization treatments of the green seaweed ulva rotundata chlorophyta on the extraction yield the physico chemical and rheological properties of Ulvan
Carbohydrate Polymers, 2008Co-Authors: Annie Robic, Jean-francois Sassi, Marc LahayeAbstract:Abstract The impact of freezing, freeze-drying, hot-air drying, brining and dry salting stabilization methods of Ulva rotundata has been studied on the yield, physico-chemical characteristics and rheological properties of Ulvan. Frozen (−30 and −80 °C) and freeze-dried algae yielded Ulvan extracts mainly composed of high molecular weight polysaccharides. These had the highest intrinsic viscosity and conservation modulus (G′) as copper/borate gels compared to Ulvan from fresh algae (taken as a reference) or Ulvan extracted from algae stabilized by other means. Cold stabilizations of algae yielded the lowest amounts of Ulvan. High Ulvan yields were obtained from Ulva air-dried at 50 and 70 °C but that at 50 °C was lower than that at 70 °C. Gelling properties and intrinsic viscosities from these Ulvans were better than that of fresh algae but lower than from cold treated seaweeds. Brining induced Ulvan degradation with poor rheological properties of the extracts compared to Ulvan from fresh algae. However, this process appears to ease extraction of polysaccharides. Compared to fresh algae, salted seaweeds stored at room temperature yielded degraded Ulvan. Decreasing the salting process temperature to 4 °C preserved Ulvan composition, structure and properties. However, Ulva salting hinders drastically Ulvan extraction. The different stabilization processes affected the chemical composition of Ulvan extracts and in particular, sulphate and protein contents. The results show that different stabilization conditions of Ulva biomass can be selected according to their cost-effectiveness and the required Ulvan chemical and macromolecular characteristics.
Bimalendu Ray - One of the best experts on this subject based on the ideXlab platform.
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chemical characterisation and gelling properties of cell wall polysaccharides from species of ulva ulvales chlorophyta
Hydrobiologia, 1996Co-Authors: Marc Lahaye, Bimalendu Ray, Bernard Quemener, Stephanie Baumberger, Monique A V AxelosAbstract:Two alkali-soluble polysaccharide fractions from the cell wall of Ulva ‘rigida’ were determined to be β-1,4-linked glucoxylans and a β–1,4-linked glucuronan by chemical and NMR spectroscopic analysis. The 13C NMR spectrum of water-soluble xyloglucuronorhamnan sulfate from Ulva ‘rigida’ referred to as Ulvan is reported and the 13C and 1H NMR chemical shifts of its major repeating unit, the aldobiuronic acid β-D-GlcA-(1,4)-L-Rha, are given. The composition and gelling properties of Ulvan from Ulva species from ‘green tides’ are also reported. The thermoreversible gel required both calcium and borate ions and the shear storage modulus G’ was ion concentration dependent. The mechanism of gelation and the associations of the different Ulva cell wall soluble polysaccharides are discussed.
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cell wall polysaccharides from the marine green alga ulva rigida ulvales chlorophyta nmr analysis of Ulvan oligosaccharides
Carbohydrate Research, 1996Co-Authors: Marc Lahaye, Bimalendu RayAbstract:In order to obtain information on sugar sequences in the water soluble polysaccharides from Ulva "rigida", oligosaccharides were purified by anion exchange and gel permeation chromatography from the partial acid hydrolysate of the native or desulfated Ulvan. The chemical structure and sugar sequence of these oligomers were determined by 1H and 13C NMR spectroscopy to be alpha-L-rhamnosyl (1-->4) D-xylose, beta-D-glucuronosyluronic acid (1-->2)-alpha-L-rhamnosyl (1-->4) D-xylose, beta-D-glucuronosyluronic acid (1-->4) L-rhamnose 3 sulfate, beta-D-glucuronosyluronic acid (1-->4) [beta-D-glucuronosyluronic acid (1-->2)] L-rhamnose and beta-D-glucuronosyluronic acid (1-->4) [beta-D-glucuronosyluronic acid (1-->2)] alpha-L-rhamnosyl (1-->4) D-xylose. The sugar linkages and particularly the branching and the sulfate position were in total agreement with previous chemical results.
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Cell-wall polysaccharides from the marine green alga Ulva "rigida" (ulvales, chlorophyta). Extraction and chemical composition
Carbohydrate Research, 1995Co-Authors: Bimalendu Ray, Marc LahayeAbstract:Cell-wall polysaccharides from the green seaweed Ulva "rigida" were extracted sequentially with oxalate, 1 and 4 M KOH, sodium chlorite and 4 M KOH again. The chemical composition of the soluble and insoluble extracts and of the DEAE-Sepharose CL-6B fractions of the soluble polysaccharide were determined. Three main types of polysaccharide families were solubilized. The major family was composed of sulfated glucuronorhamnoxyloglycans (Ulvan) and was essentially extracted with oxalate. Two hemicellulosic fractions were also isolated and consisted of glucuronans and glucoxylans. Minor fractions consisting of sulfated polysaccharides containing glucose, xylose, mannose and protein were also isolated. © 1995.
Jean-francois Sassi - One of the best experts on this subject based on the ideXlab platform.
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sulphated polysaccharides from ulva clathrata and cladosiphon okamuranus seaweeds both inhibit viral attachment entry and cell cell fusion in ndv infection
Marine Drugs, 2015Co-Authors: Jose Alberto Aguilarbriseno, Jean-francois Sassi, Denis Ricquemarie, Edgar Mendozagamboa, Cristina Rodriguezpadilla, Lucia Elizabeth Cruzsuarez, Pablo Zapatabenavides, Laura M TrejoavilaAbstract:Sulphated polysaccharides (SP) extracted from seaweeds have antiviral properties and are much less cytotoxic than conventional drugs, but little is known about their mode of action. Combination antiviral chemotherapy may offer advantages over single agent therapy, increasing efficiency, potency and delaying the emergence of resistant virus. The paramyxoviridae family includes pathogens causing morbidity and mortality worldwide in humans and animals, such as the Newcastle Disease Virus (NDV) in poultry. This study aims at determining the antiviral activity and mechanism of action in vitro of an Ulvan (SP from the green seaweed Ulva clathrata), and of its mixture with a fucoidan (SP from Cladosiphon okamuranus), against La Sota NDV strain. The Ulvan antiviral activity was tested using syncytia formation, exhibiting an IC50 of 0.1 μg/mL; Ulvan had a better anti cell-cell spread effect than that previously shown for fucoidan, and inhibited cell-cell fusion via a direct effect on the F0 protein, but did not show any virucidal effect. The mixture of Ulvan and fucoidan showed a greater anti-spread effect than SPs alone, but Ulvan antagonizes the effect of fucoidan on the viral attachment/entry. Both SPs may be promising antivirals against paramyxovirus infection but their mixture has no clear synergistic advantage.
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Ulvan lyases isolated from the flavobacteria persicivirga Ulvanivorans are the first members of a new polysaccharide lyase family
Journal of Biological Chemistry, 2011Co-Authors: Pi Nyvall Collen, Jean-francois Sassi, Helene Rogniaux, Helene Marfaing, William HelbertAbstract:Ulvans are complex sulfated polysaccharides found in the cell walls of green algae belonging to the genus Ulva. These polysaccharides are composed of disaccharide repetition moieties made up of sulfated rhamnose linked to either glucuronic acid, iduronic acid, or xylose. Two Ulvan lyases of 30 and 46 kDa were purified from the culture supernatant of Persicivirga Ulvanivorans. Based on peptide sequencing, the gene encoding the 46-kDa Ulvan lyase was cloned. Sequence analysis revealed that the protein is modular and possesses a catalytic module similar to that of the 30-kDa Ulvan lyase along with a module of unknown function. The Ulvan-degrading function of the gene was confirmed by expression of the catalytic module in a heterologous system. The gene encoding the catalytic module has no sequence homolog in sequence databases and is likely to be the first member of a novel polysaccharide lyase family. Analysis of degradation products showed that both the 30- and 46-kDa Ulvan lyases are endolytic and cleave the glycosidic bond between the sulfated rhamnose and a glucuronic or iduronic acid.
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Ulvan lyases isolated from the flavobacteria persicivirga Ulvanivorans are the first members of a new polysaccharide
2011Co-Authors: Pi Nyvall Collen, Jean-francois Sassi, Helene Rogniaux, Helene Marfaing, William HelbertAbstract:. Based on peptide sequencing, the gene encoding the46-kDa Ulvan lyase was cloned. Sequence analysis revealed thatthe protein is modular and possesses a catalytic module similarto that of the 30-kDa Ulvan lyase along with a module ofunknown function. The Ulvan-degrading function of the genewasconfirmedbyexpressionofthecatalyticmoduleinaheter-ologoussystem.Thegeneencodingthecatalyticmodulehasnosequence homolog in sequence databases and is likely to be thefirst member of a novel polysaccharide lyase family. Analysis ofdegradation products showed that both the 30- and 46-kDaUlvan lyases are endolytic and cleave the glycosidic bondbetween the sulfated rhamnose and a glucuronic or iduronicacid.
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determination of the chemical composition of Ulvan a cell wall polysaccharide from ulva spp ulvales chlorophyta by ft ir and chemometrics
Journal of Applied Phycology, 2009Co-Authors: Yannick Lerat, Annie Robic, Jean-francois Sassi, Dominique Bertrand, Marc LahayeAbstract:The water-soluble cell wall polysaccharides from green seaweeds of Ulva spp. (Ulvales, Chlorophyta), referred to as Ulvan, demonstrate composition- and structure-related functional properties. Mid-infrared spectroscopy combined with chemometric techniques was investigated as a means to rapidly predict the chemical composition of Ulvan extracts. A calibration was realized with 41 Ulvan extracts from two Ulva species. The variables studied included the constituent sugars (rhamnose, xylose, glucose, galactose, glucuronic acid, iduronic acid), protein, and sulfate contents. The correlation between Fourier transform infrared and chemical data was developed using partial least squares (PLS) regression with full cross-validation (leave one out). The coefficients of determination in cross-validation (\(R_{{\text{CAL}}}^2 \)) and the standard error in cross-validation were determined for each variable. The PLS model validation resulted in a coefficient of determination (\(R_{{\text{VAL}}}^2 \)) and a standard error in prediction. Good predictions were obtained for rhamnose (\(R_{{\text{VAL}}}^2 \) = 0.9244), xylose (\(R_{{\text{VAL}}}^2 \) = 0.8758), glucuronic acid (\(R_{{\text{VAL}}}^2 \) = 0.9415), and sulfate (\(R_{{\text{VAL}}}^2 \) = 0.9218), which are the main Ulvan constituents. However, minor components such as proteins, glucose, galactose, and iduronic acid were not correctly predicted. This study showed that mid-infrared spectroscopy combined with PLS regression is a reliable and fast method for the quantification of the main chemical constituents of Ulvan extracts.
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structure and interactions of Ulvan in the cell wall of the marine green algae ulva rotundata ulvales chlorophyceae
Carbohydrate Polymers, 2009Co-Authors: Annie Robic, Yannick Lerat, Jean-francois Sassi, Corinne Rondeaumouro, Marc LahayeAbstract:Abstract Ulvan, the sulfated cell-wall polysaccharides from green seaweeds ( Ulva species), presents structural and functional properties of interest for different applications. Its extraction yield in water varies depending on the species, the period of collect and the mode of conservation of algae. To identify limits of extraction, the structure and interactions of Ulvan in the cell wall of Ulva were investigated following a sequential solvent extraction. Hot sodium oxalate and hot dilute HCl were the two major extracts. Other solvents affecting protein structure or low hydrogen bonded polymers yielded minor Ulvan fractions but affected solid state 13 C NMR spectra indicating that proteins likely contributed to cross-link and/or to entrap Ulva cell wall polysaccharides. Ulvan-lyase degradation showed that Ulvan consisted in a wide continuum of related polysaccharides differing in the extent and type of fine structural characteristics. Besides solvent acidity, particle size of seaweeds was an important parameter controlling the Ulvan extraction efficiency. Major Ulvan cell wall interactions were discussed with regard to ionic interactions, covalent linkages and peculiar solution behavior of Ulvan in various physicochemical environments.
Quanbin Zhang - One of the best experts on this subject based on the ideXlab platform.
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subchronic toxicity study of Ulvan from ulva pertusa chlorophyta in wistar rats
Food and Chemical Toxicology, 2013Co-Authors: Xiaolei Liu, Liye Huang, Kai Wang, Dongmei Liu, Shunmei Liu, Quanbin ZhangAbstract:Ulvan extracted from Ulva pertusa (Chlorophyta) is a group of sulfated heteropolysaccharide, for simplicity, the sulfated polysaccharide is referred to as Ulvan in this paper. To our knowledge, there is no detailed report investigating the toxicity of Ulvan. In this study, the subchronic (6 months) toxicity of varying levels of Ulvan extracted from U. pertusa was investigated in Wistar rats after oral administration. ALT, ALB, ALP, WBC, PLT, and liver relative organ weigh of female rats showed significantly difference at 3000 mg/kg body weight per day, compared with control group. On the other hand, TG, T-CHO concentrations of female rats (6 months) were significantly decreased at 600, 1200 and 3000 mg/kg body weight per day. This result proved that Ulvan had antihyperlipidemic activity. Beside, Ulvan showed anticoagulant activity in this study. Overall, our findings indicated that Ulvan had affected specific hematology, serum biochemistry parameters and liver, and had great differences between males and females rats. (C) 2013 Elsevier Ltd. All rights reserved.
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antihyperlipidemic activity of high sulfate content derivative of polysaccharide extracted from ulva pertusa chlorophyta
Carbohydrate Polymers, 2012Co-Authors: Huimin Qi, Liye Huang, Quanbin ZhangAbstract:In this study, high sulfate content Ulvan (HU) was prepared with sulfur trioxide/N,N-dimethylformamide (SO3-DMF) in formamide, and the antihyperlipidemic activity of Ulvan and HU in mice was determined. Obvious differences in antihyperlipidemic activity between natural Ulvan and HU were observed, moreover, the antihyperlipidemic activity of HU-fed 250 mg/kg was the strongest, compared to natural Ulvan fed group, triglyceride (TG) and low density lipoprotein cholesterol (LDL-C) concentrations were significantly decreased 28.1% (P < 0.05) and 28.4% (P < 0.01), respectively. It was likely that the sulfate content had significant effect on the antihyperlipidemic activity. On the other hand, the results proved that the antihyperlipidemic activity was not concentration dependent for HU-fed mice. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
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synthesis and antihyperlipidemic activity of acetylated derivative of Ulvan from ulva pertusa
International Journal of Biological Macromolecules, 2012Co-Authors: Xiaolei Liu, Jinbao Zhang, Yu Duan, Xiaolan Wang, Quanbin ZhangAbstract:In this study, acetylated Ulvan (AU) was prepared with acetic anhydride in N,N-dimethylacetamide, and the antihyperlipidemic activity of natural Ulvan and its acetylated Ulvan derivative (AU) in mice was determined. Obvious differences in antihyperlipidemic activity between natural Ulvan and its derivative were observed, moreover, AU showed stronger antihyperlipidemic activity on triglyceride (TG) and low density lipoprotein cholesterol (LDL-C).
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in vitro antioxidant activity of acetylated and benzoylated derivatives of polysaccharide extracted from ulva pertusa chlorophyta
Bioorganic & Medicinal Chemistry Letters, 2006Co-Authors: Huimin Qi, Quanbin Zhang, Tingting Zhao, Rugui Hu, Kun Zhang, Zhien LiAbstract:The antioxidant activity of natural Ulvan and its derivatives (acetylated and benzoylated Ulvans) in vitro was determined, including scavenging activity against superoxide and hydroxyl radicals, reducing power, and chelating ability. Obvious differences in antioxidant activity between natural Ulvan and its derivatives were observed, moreover, the antioxidant activity of acetylated and benzoylated Ulvans was stronger than that of natural Ulvan. (C) 2006 Elsevier Ltd. All rights reserved.
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antioxidant activity of different sulfate content derivatives of polysaccharide extracted from ulva pertusa chlorophyta in vitro
International Journal of Biological Macromolecules, 2005Co-Authors: Huimin Qi, Xizhen Niu, Quanbin Zhang, Tingting Zhao, Hong Zhang, Rong Chen, Zhien LiAbstract:Polysaccharide extracted from Ulva pertusa (Chlorophyta) is a group of sulfated heteropolysaccharide; for simplicity, the sulfated polysaccharide is referred to as Ulvan in this paper. In this study, different sulfate content Ulvans were prepared with sulfur trioxide/N,N-diinethylformamide (SO3-DMF) in formamide, and their antioxidant activities were investigated including scavenging activity of superoxide and hydroxyl radicals, reducing Power and metal chelating ability. As expected, we obtained several satisfying results, as follows: firstly, high sulfate content Ulvans had more effective scavenging activity on hydroxyl radical than natural Ulvan. Secondly, comparing with natural Ulvan, high sulfate content Ulvans exhibited stronger reducing power. Thirdly, HU4 (sulfate content, 30.8%) and HU5 (sulfate content, 32.8%) showed more pronounce chelating ability on ferrous ion at high concentration than other samples. (c) 2005 Elsevier B.V. All rights reserved.