The Experts below are selected from a list of 87780 Experts worldwide ranked by ideXlab platform
P Valachovic - One of the best experts on this subject based on the ideXlab platform.
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ultrasound assisted extraction of water soluble Polysaccharides from the roots of valerian valeriana officinalis l
Ultrasonics Sonochemistry, 2002Co-Authors: Z Hromadkova, Anna Ebringerova, P ValachovicAbstract:Abstract The insoluble plant residues, obtained after preparation of medicinal tinctures from the roots of valerian (Valeriana officinalis L.) by classical and ultrasound-assisted extraction with aqueous ethanol in a pilot plant, were subsequently treated with hot water to isolate the accessible polysaccharide cell wall components. At almost equal amounts of the hot-water extractable material, the yields of the recovered Polysaccharides were lower in the ultrasonical experiment. This is due to the fact that a part of accessible Polysaccharides were already solubilised by the aqueous ethanol and recoverable from the medicinal tincture. Therefore, the net yield of extracted Polysaccharides was enhanced in the ultrasonical procedure. This fact as well as the sugar composition and structural features of the isolated Polysaccharides suggest that ultrasonication have attacked the integrity of cell walls, released and degraded its most accessible Polysaccharides (pectic Polysaccharides and starch) and increased also the extractibility of its less accessible components – xylan, mannan and glucan. The water-soluble polysaccharide fractions from both the conventional and ultrasonical experiments exhibit significant immunostimulatory activities in mitogenic and comitogenic thymocyte tests.
Mingxing Zhao - One of the best experts on this subject based on the ideXlab platform.
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free radical degradation by fe2 vc h2o2 and antioxidant activity of polysaccharide from tremella fuciformis
Carbohydrate Polymers, 2014Co-Authors: Zhongsha Zhang, Xiaomei Wang, Mingxing ZhaoAbstract:The free-radical degradation and antioxidant activity of polysaccharide from Tremella fuciformis was investigated. In present study, the combination of Fe(2+), ascorbic acid and H2O2 was used as degradation regents in order to obtain the lower molecular weight product. The result ascertained oxidative-reduce degradation did not change the main structure of Polysaccharides in the test conditions. Five degraded Polysaccharides were selected to evaluate their antioxidant activities in vitro. It was found that the degraded sample with lower molecular weight possessed the higher antioxidant activities. It was possible that free-radical degradation is an effective way for enhancing antioxidant activity to decrease molecular weight of Polysaccharides.
Zhi Zhang - One of the best experts on this subject based on the ideXlab platform.
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in vitro antioxidant activities of sulfated derivatives of Polysaccharides extracted from auricularia auricular
International Journal of Molecular Sciences, 2011Co-Authors: Hua Zhang, Zhenyu Wang, Lin Yang, Xin Yang, Xue Wang, Zhi ZhangAbstract:In this research, two types of sulfated polysaccharide derivatives were successfully synthesized. Their antioxidant activities were investigated by employing various established in vitro systems. In addition, the degree of sulfation was evaluated using ion-chromatography and IR spectra. The results verify that, when employing scavenging superoxide radical tests, both the sulfation of acid Auricularia auricular Polysaccharides (SAAAP) and the sulfation of neutral Auricularia auricular Polysaccharides (SNAAP) derivatives possessed considerable antioxidant activity and had a more powerful antioxidant competence than that of the native non-sulfated Polysaccharides (AAAP and NAAP). On the other hand, AAAP and NAAP exhibited stronger activity on scavenging both the hydroxyl radical and lipid peroxidation. Available data obtained with in vitro measurements indicates that the sulfated groups of AAAP and NAAP played an important role on antioxidant activity. In sum, the research demonstrates that the antioxidant activity of sulfated polysaccharide derivatives in vitro has a potential significance for seeking new natural antioxidant protective agents.
Yumin Du - One of the best experts on this subject based on the ideXlab platform.
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preparation and in vitro antioxidant activity of lacquer Polysaccharides with low molecular weights and their sulfated derivatives
International Journal of Biological Macromolecules, 2010Co-Authors: Yumin Du, Jianhong Yang, Yan Li, Le ZhangAbstract:Abstract Lacquer polysaccharide (LP) from the sap of the lac tree ( Rhus vernicifera ) was degraded by hydrochloric acid. The molecular weights ( M w ) of hydrolysis products of lacquer polysaccharide (LPD) decreased with the increase of the reaction temperature. Sulfated derivatives (LPDSs) of LPDs were prepared by the reaction of LPDs with sulfur trioxide–pyridine complex (SO 3 ·Py) in DMSO. The structures of Polysaccharides were analyzed by GPC, FT-IR and 1 H NMR spectroscopy. Reducing power, superoxide radical scavenging ability and metal chelating capacity were used for the evaluation of all Polysaccharides in vitro. Results indicated that LPDS with moderate M w and DS expressed good antioxidant capacity.
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the structure anticoagulant activity relationships of sulfated lacquer polysaccharide effect of carboxyl group and position of sulfation
International Journal of Biological Macromolecules, 2005Co-Authors: Jianhong Yang, Yumin Du, Ronghua HuangAbstract:Regiospecific oxidation of the primary hydroxyl groups in lacquer polysaccharide (LPL, Mw 6.85 × 104) and its NaIO4 oxidation derivatives (LPLde) to C-6 carboxy groups was achieved with NaOCl in the presence of Tempo® and NaBr. Sulfate groups were incorporated into the oxidated Polysaccharides using Py·SO3 complex as a reagent. Reactivity of polysaccharide hydroxyl group was C-6 > C-2 > C-4. Sulfate groups were mainly linked to the second hydroxy at C-2 in the products. The results of APTT assay showed after incorporation of carboxyl groups into lacquer Polysaccharides, the intrinsic coagulation pathway was promoted, and all sulfated Polysaccharides had very weak anticoagulant activity within the scope of studied DS (0.39–1.11). These indicated that carboxyl groups and sulfate groups had the synergistic action. At the same time, the anticoagulant activity increased very slowly with the DS in the second hydroxy. This indicated that 6-O-SO3− in the side chains took an important role in the anticoagulant activity.
Xiaomei Wang - One of the best experts on this subject based on the ideXlab platform.
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free radical degradation by fe2 vc h2o2 and antioxidant activity of polysaccharide from tremella fuciformis
Carbohydrate Polymers, 2014Co-Authors: Zhongsha Zhang, Xiaomei Wang, Mingxing ZhaoAbstract:The free-radical degradation and antioxidant activity of polysaccharide from Tremella fuciformis was investigated. In present study, the combination of Fe(2+), ascorbic acid and H2O2 was used as degradation regents in order to obtain the lower molecular weight product. The result ascertained oxidative-reduce degradation did not change the main structure of Polysaccharides in the test conditions. Five degraded Polysaccharides were selected to evaluate their antioxidant activities in vitro. It was found that the degraded sample with lower molecular weight possessed the higher antioxidant activities. It was possible that free-radical degradation is an effective way for enhancing antioxidant activity to decrease molecular weight of Polysaccharides.
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extraction of the Polysaccharides from five algae and their potential antioxidant activity in vitro
Carbohydrate Polymers, 2010Co-Authors: Zhongshan Zhang, Xiaomei Wang, Feng Wang, Xiaolei Liu, Yun Hou, Quanbin ZhangAbstract:The sulfated Polysaccharides extracted from algae possess excellent antioxidant activities. In this study, we prepared five Polysaccharides extracted from five algae including one brown alga Laminaria japonica. one red alga Porphyra haitanensis and three green algae Ulva pertusa, Enteromorpha linza and Bryopsis plumose. And then the antioxidant activities of all the samples were investigated including scavenging effects of superoxide and hydroxyl radicals, and reducing power. The chemical analysis and FT-IR spectrum showed these extracts were Polysaccharides. And in addition, we found that certain polysaccharide exhibited stronger antioxidant activity in certain antioxidant activity. Factors effecting and attributing to radical scavenging effect need to be further studied. (C) 2010 Elsevier Ltd. All rights reserved.
