莲子多糖的结构分析及抗氧化活性

用热水浸提、乙醇沉淀、Sevag法除蛋白分离得到水溶性莲子粗多糖。经十六烷基三甲基溴化铵（CTAB）沉淀,硼酸反应以及SephadexG-150层析纯化,得到3种莲子多糖SN1、SN2、SN3。用气相色谱、红外光谱、紫外光谱分析其化学结构。结果表明：SN1主要由葡萄糖、半乳糖组成,含a—D-吡喃葡萄糖环;SN2主链为葡聚糖、并含有其他4种单糖;SN3含7种单糖,并推测是一种酸性氨基多糖或蛋白多糖。体外抗氧化活性实验表明莲子多糖具有一定的清除自由基能力,清除·O2-的能力较强。     

银耳碱提多糖的纯化、化学表征及其抗氧化作用的研究(英文)

研究银耳孢子发酵物中的多糖类化学成分,并探讨了分离得到的一个多糖组分的抗氧化活性。银耳孢子发酵粉用热水煮提除去水溶性组分后,再采用0.5 mol.L-1的氢氧化钠溶液提取,Sevage法除蛋白,用乙醇沉淀得到粗多糖。粗多糖经DEAE-32-纤维素和Sephadex G-200分离纯化得到分布均一的多糖TFBP-A。糖组成分析显示,TFBP-A单糖组成为:甘露糖:半乳糖:葡萄糖,摩尔比为90∶5∶5;HPGPC测定TFBP-A分子量为58962。TFBP-A的抗氧化活性实验显示:在H2O2引起的红细胞溶血试验中,以蒸馏水抑制率为0%计算,TFBP-A抑制率为78.6%;在超氧阴离子自由基的清除作用实验中,TFBP-A最高抑制率为53%;在清除羟基自由基实验中,TFBP-A的EC50为0.191 mg.mL-1。从银耳孢子发酵物中用碱液提取得到的多糖组分TFBP-A为酸性杂多糖,重均分子量为58962,且具有一定的抗氧化活性。     

猴头菌子实体和菌丝体多糖的分离纯化与理化特征的比较*

人工栽培的猴头菌子实体和固体培养的菌丝体分别经热水提取,浓缩、醇析后得子实体粗多糖（HFP）和菌丝体粗多糖（HMP）,HFP的得率和多糖含量均高于HMP;两者再经透析、Sevag法脱蛋白、乙醇分级沉淀、SephadexG-100柱层析纯化,得子实体纯多糖hfp-1和菌丝体纯多糖 hmp-2,经HPLC检测hfp-1和hmp-2为单一均匀多糖。气相色谱分析表明hfp-1的单糖组成为阿拉伯糖、甘露糖、半乳糖和葡萄糖,摩尔比为：0.12：0.04：1.00：0.71;hmp-2的单糖组成为阿拉伯糖、木糖、甘露糖、半乳糖和葡萄糖,摩尔比为：0.25：0.41：0.31：1.00：0.29。紫外光谱分析表明组成中不含核酸和蛋白质,红外光谱分析二者均有多糖特征吸收峰,hfp-1有β-型连接的吸收峰,hmp-2无明显的β-型连接的吸收峰;经HPLC进行分子量测定,hfp-1的分子量为54000,hmp-2的分子量为68000。猴头菌子实体多糖和菌丝体多糖在化学组成上有一定的差异。     

猴头菌子实体和菌丝体多糖的分离纯化与理化特征的比较

人工栽培的猴头菌子实体和固体培养的菌丝体分别经热水提取,浓缩、醇析后得子实体粗多糖（HFP）和菌丝体粗多糖（HMP）,HFP的得率和多糖含量均高于HMP;两者再经透析、Sevag法脱蛋白、乙醇分级沉淀、SephadexG-100柱层析纯化,得子实体纯多糖hfp-1和菌丝体纯多糖hmp-2,经HPLC检测hfp-1和hmp-2为单一均匀多糖,气相色谱分析表明hfp-1的单糖组成为阿拉伯糖、甘露糖、半乳糖和葡萄糖,摩尔比为：0.12:0.04:1.00:0.71;hmp-2的单糖组成为阿拉伯糖、木糖、甘露糖、半乳糖和葡萄糖,磨尔比为：0.25:0.41:0.31:1.00:0.29。紫外光谱分析表明组成中不含核酸和蛋白质,红外光谱分析二者均有多糖特征吸收峰,hfp-1有β-型连接的吸收峰,hmp-2无明显的β-型连接的吸收峰;经HPLC进行分子量测定,hfp-1的分子量为54000,hmp-2的分子量为68000,猴头菌子实体多糖和菌丝体多糖在化学组成上有一定的差异。     

两种灵芝孢子粉多糖的分离纯化和结构

本文采用水提醇沉法从灵芝孢子粉中提取其粗多糖,经Sepharose CL-6B凝胶柱层析分离得两种主要成分LBPI和LBPII,经高效液相色谱鉴定,均为高均一性成分,分子量分别为9.17×10 ⁴和1.86×10 ⁴;经酸水解、乙酰化和气相色谱分析,确定LBPI的单糖组成为甘露糖、半乳糖和葡萄糖,LBPII的单糖组成为鼠李糖、甘露糖、半乳糖和葡萄糖;通过高碘酸氧化、甲基化和GC-MS进行结构分析,确定LBPI中葡萄糖残基连接方式为1→、1→4,6和1→3,6连接,半乳糖残基为1→6连接,甘露糖残基为1→3,6连接,LBPII中鼠李糖残基连接方式为1→连接,葡萄糖残基为1→、1→4、1→6、1→4,6和1→3,6连接,半乳糖残基为1→6连接,甘露糖残基为1→2,3,6连接。综上,两种多糖LBPI和LBPII均为多分支的中型杂多糖,但两者的单糖组成和连接方式存在差异,这两种多糖成分均为首次报道,可望为灵芝孢子粉的成分、活性研究和资源开发提供理论依据。     

短裙竹荪多糖Dd-S3P的分离纯化及其性质研究

短裙竹荪子实体经2％Na2CO3溶液提取,用蛋白酶法和Sevag法相结合除去蛋白,乙醇分级沉淀,级分3经DEAE－SephadexA－25柱层析纯化得到短裙竹蒸蒸荪多糖DdS3P．经测定该多糖为均一组分,分子量约为3．8×105,红外光谱呈现出典型的多糖吸收峰,含有α-型糖苷连接键,紫外扫描无核酸和蛋白质的特征吸收峰．纸层析和气相层析分析得知Dd－S3P含有D-葡萄糖（D－Glc）、D-甘露糖（D－Man）和D-木糖（D－Xyl）,其摩尔比为1．83：1．00：1．21．经动物试验表明此多糖对小鼠S-180有一定的抑制作用,抑瘤率约31．3％．     

猪肚菇多糖WPG1的相对分子质量测定及原子力显微镜观测

热水提取猪肚菇粗多糖中的酸性多糖WPG1,经凝胶纯化后用高效液相色谱（HPLC）测定其相对分子质量,用气相色谱对其单糖组成进行分析,用原子力显微镜（AFM）对其形态结构进行观测。结果表明：酸性多糖WPG1经SephacrylS-300凝胶层析纯化后得到WPG1-1和WPG1-2这2个组分; 经HPLC分析可知WPG1-1与WPG1-2均为单一组分,其相对分子质量分别为1.7×106和1.6×104; WPG1-1与WPG1-2的单糖组成主要是糖醛酸、甘露糖、葡萄糖和半乳糖; 原子力显微镜观测图分析表明WPG1-1为网链状聚集体结构,WPG1-2呈梭状聚集体,两者均非单链存在。     

当归水溶性多糖级分As-Ⅲa和As-Ⅲb的纯化鉴定与结构研究

当归热水抽提得到的粗多糖,经乙醇分级沉淀,ＤＥＡＥ纤维素分离和ＳｅｐｈａｄｅｘＧ１５０柱层析纯化,得到水洗脱级分Ａｓ—Ⅲａ和碱洗脱级分Ａｓ—Ⅲｂ两个多糖级分。经测定这两级分为均一组分。红外光谱呈现出典型的多糖吸收峰。气相色谱分析表明Ａｓ—Ⅲａ由葡萄糖组成,Ａｓ—Ⅲｂ由葡萄糖、甘露糖和阿拉伯糖组成。高碘酸氧化及Ｓｍｉｔｈ降解分析表明Ａｓ—Ⅲａ的单体通过α（１→３）糖苷键相连,Ａｓ—Ⅲｂ主要通过（１→４）和（１→６）糖苷键相连。     

灰树花多糖PGF-2的理化性质及化学结构的初步表征

本文利用仪器分析技术对灰树花多糖级分PGF-2的理化性质和化学结构进行了研究。灰树花粗多糖PGF经DEAE—Sephadex A-25柱层析分离得到一种多糖级分为糖蛋白质缀合物PGF-2,其多糖含量95.4%,纸层析及Sephadex G-200凝胶柱层析证实PGF-2为均一多糖;凝胶渗透色谱测定其数均分子量Mn为118 803 Dal,重均分子量Mw为119 612 Dal;经气相色谱分析PGF-2的糖基由葡萄糖、甘露糖和半乳糖组成,摩尔比为1:2.35:1.22;氨基酸分析结果表明PGF-2的蛋白质由16种氨基酸组成。红外光谱与核磁共振谱证实PGF-2主要存在α型糖苷键。由β-消除反应推断PGF-2中多糖与氨基酸的连接方式以-O-Ser连接。     

链霉菌H03发酵液中具有抗菌活性多糖的分离纯化及其单糖组成分析

时链霉菌H03发酵产物进行了分离纯化,并对其进行了初步鉴定．对链霉菌H03发酵产物离心,采用减压蒸馏,乙醇沉淀,沉淀组分用Sevage法、盐析法去蛋白,用透析法除去小分子物质以及用Sephadex-100柱层析等技术进行纯化,纯化物质仍具有较强的抗菌活性、利用化学方法、紫外光谱、红外光谱、气质联用等方法分析该抗菌活性物质的理化性质．结果表明：从链霉菌的发酵产物中分离纯化得到的具有抗菌活性物质是多糖,这种多糖是由甘露糖、葡萄糖、半乳糖3种单糖组成的,其组成比例约为2：1：1．     

Formation of a soluble amylopectin-like polysaccharide in potato tubers

When potato sprouts or potato tuber slices were incubated with 0.1 m glucose 1-phosphate, a soluble amylopectin-like polysaccharide was excreted to the medium. This polysaccharide was found to be a very good primer for phosphorylase and a poor one for starch synthetase. Beside the formation of this extracellular polysaccharide, a more branched intracellular polysaccharide could be isolated. This polysaccharide was an excellent primer for starch synthetase. Fructose 6-phosphate, glucose 6-phosphate, fructose 1,6-diphosphate, glucose or sucrose could not substitute for glucose 1-phosphate. 2,4-Dinitrophenol or nitrogen did not affect the excretion of the polysaccharide. Some properties of these 2 polysaccharides are described.     

Pyrolysis of cellulose

Pyrolysis of cellulose under vacuum and atmospheric pressure gave a tar containing various amounts of 1,6-anhydro-β-D-glucopyranose, 1,6-anhydro-β-D-glucofuranose, α- and β-D-glucose, 3-deoxy-D-erythro-hexosulose, oligo- and polysaccharides, and some dehydration products. The polysaccharide fraction had no reducing end-group, was randomly linked, contained some furanoid rings, and was very similar to the polysaccharide condensation-product of 1,6-anhydro-β-D-glucose. These results are consistent with a series of inter- and intra-molecular transglycosylation and dehydration and rehydration reactions.     

紫芝细胞壁大分子量葡聚糖的纯化及结构鉴定

采用超微粉碎、热水浸提法从紫芝子实体水提残渣中获得细胞壁粗多糖,通过30%乙醇沉淀、20%醇洗的方法纯化出大分子量均一多糖GSCW30E-20E。苯酚硫酸法检测其多糖含量为98.03%,单糖组成分析显示其仅由葡萄糖组成,高效凝胶尺寸排阻色谱-多角度激光散射仪-示差折光检测技术测定其重均分子量为1.552×10 ⁶g/mol。通过红外光谱、甲基化及核磁共振分析对其结构进行解析,结果表明,GSCW30E-20E是一种β-D-葡聚糖,该多糖主链由β-(1,3)-糖苷键连接而成,每3个糖残基主链上通过β-(1,6)-糖苷键连有一个葡萄糖残基为支链。     

Purification and structural characterization of a new water-soluble neutral polysaccharide GLP-F1-1 from Ganoderma lucidum

A water-soluble neutral polysaccharide (GLP-F1-1) was isolated from the fruiting bodies of Ganoderma lucidum by DEAE Sepharose Fast Flow and Sephacryl S-500 High Resolution Chromatography. The neutral polysaccharide had an average molecular weight (Mw) of approximately 2.5×10(6) kDa. GC analysis showed that this polysaccharide was mainly composed of glucose and galactose in the molar ratio of 34:1. 1H and 13C NMR spectroscopy in combination with GC-MS technique indicated that the new polysaccharide had a backbone chain of 1,4-disubstituted-β-glucoseopyranose and 1,4,6-trisubstituted-β-glucoseopyranosyl, while the branched chains were mainly composed of 1,6-disubstituted-β-glucopyranosyl and 1,4-disubstituted-β-galactoseopyranosyl residues.     

pH-imprinted lipase catalyzed synthesis of dextran fatty acid ester

The application of enzymatic catalysis for the synthesis of polysaccharide-based surfactants was investigated. The polysaccharide dextran, a neutral bacterial polysaccharide consisting of -1,6 linked glucose units, was chemically modified by the attachment of hydrophobic groups through a transesterification reaction with a vinyl decanoate. A screening of commercially available lipases and protease for the synthesis of amphiphilic polysaccharides in DMSO suggested that lipase AY from Candida rugosa modified dextran T-40 with vinyl decanoate at the highest conversion. A pH-adjustment in a phosphate buffer at pH 7.5 prior to use is crucial to make this enzyme active in DMSO. The effect of enzyme concentration and mole ratio of fatty ester to dextran T-40 on the conversion and the rate of reaction were studied. Finally, investigation of the kinetics and regioselectivity of lipase AY-catalyzed modification offer a possibility to regulate the position and the extent of hydrophobic group attached to dextran. These two properties are fundamental for controlling the physico-chemical properties of the final polymeric surfactants.     

Structural features of immunologically active polysaccharides from Ganoderma lucidum.

Three polysaccharides, two heteroglycans (PL-1 and PL-4) and one glucan (PL-3), were solubilized from the fruit bodies of Ganoderma lucidum and isolated by anion-exchange and gel-filtration chromatography. Their structural features were elucidated by glycosyl residue and glycosyl linkage composition analyses, partial acid hydrolysis, acetolysis, periodate oxidation, 1D and 2D NMR spectroscopy, and ESI-MS experiments. The data obtained indicated that PL-1 had a backbone consisting of 1,4-linked alpha-D-glucopyranosyl residues and 1,6-linked beta-D-galactopyranosyl residues with branches at O-6 of glucose residues and O-2 of galactose residues, composed of terminal glucose, 1,6-linked glucosyl residues and terminal rhamnose. PL-3 was a highly branched glucan composed of 1,3-linked beta-D-glucopyranosyl residues substituted at O-6 with 1,6-linked glucosyl residues. PL-4 was comprised of 1,3-, 1,4-, 1,6-linked beta-D-glucopyranosyl residues and 1,6-linked beta-D-mannopyranosyl residues. These polysaccharides enhanced the proliferation of T- and B-lymphocytes in vitro to varying contents and PL-1 exhibited an immune-stimulating activity in mice.     

Evidence for the presence of glycogen in rat thymus

Chemical and biochemical analysis of the polysaccharide, present in rat thymus, indicate that it consists of glucose units alpha-1,4 and alpha-1,6 linked. Electron microscopy reveals the presence of a polysaccharide, similar to the beta-glycogen particles observed in liver and muscle with an average diameter of 20-30 nm. They are located in the cytoplasmic area of T-cells from the cortical region of the thymus. Enzymatic analysis indicates that the beta-particles contain a highly branched glucan with short external chains. Some of the enzymes of glycogen metabolism: synthase, phosphorylase and branching were for the first time partially purified from rat thymus and some of their properties were studied. Therefore, glycogen appeared to be synthesized in rat thymus.     

Cell-associated glucans of Burkholderia solanacearum and Xanthomonas campestris pv. citri: a new family of periplasmic glucans.

The cell-associated glucans produced by Burkholderia solanacearum and Xanthomonas campestris pv. citri were isolated by trichloroacetic acid treatment and gel permeation chromatography. The compounds obtained were characterized by compositional analysis, matrix-assisted laser desorption ionization mass spectrometry, and high-performance anion-exchange chromatography. B. solanacearum synthesizes only a neutral cyclic glucan containing 13 glucose residues, and X. campestris pv. citri synthesizes a neutral cyclic glucan containing 16 glucose residues. The two glucans were further purified by high-performance anion-exchange chromatography. Methylation analysis revealed that these glucans are linked by 1,2-glycosidic bonds and one 1,6-glycosidic bond. Our 600-MHz homonuclear and 1H-13C heteronuclear nuclear magnetic resonance experiments revealed the presence of a single alpha-1,6-glycosidic linkage, whereas all other glucose residues are beta-1,2 linked. The presence of this single alpha-1,6 linkage, however, induces such structural constraints in these cyclic glucans that all individual glucose residues could be distinguished. The different anomeric proton signals allowed complete sequence-specific assignment of both glucans. The structural characteristics of these glucans contrast with those of the previously described osmoregulated periplasmic glucans.     

Prion rods contain an inert polysaccharide scaffold

A polysaccharide consisting of mainly 1,4-linked glucose units was found associated with prion rods, which are composed mainly of insoluble aggregates of the N-terminally truncated prion protein (PrP 27-30) exhibiting the ultrastructural and tinctorial properties of amyloid. The polysaccharide differs in composition from the Asn-linked oligosaccharides and the GPI-anchor of the prion protein. Prion rods were prepared from scrapie-infected hamster brains using two different purification protocols. Prolonged digestion of rods with proteinase K reduced PrP by a factor of at least 500, leaving about 10% (w/w) of the sample as an insoluble remnant. Only glucose was obtained by acid hydrolysis of the remnant and methylation analysis showed 80% 1,4-, 15% 1,6- and 5% 1,4,6-linked glucose units. The physical and chemical properties as well as the absence of terminal glucose units indicate a very high molecular mass of the polysaccharide. No evidence was found for covalent bonds between PrP and the polysaccharide. The polysaccharide certainly contributes to the unusual chemical and physical stability of prion rods, acting like a scaffold. A potential structural and/or functional relevance of the polysaccharide scaffold is discussed.     

Branching enzyme assay: selective quantitation of the alpha 1,6-linked glucosyl residues involved in the branching points

Methods previously described for glycogen or amylopectin branching enzymatic activity are insufficiently sensitive and not quantitative. A new, more sensitive, specific, and quantitative one was developed. It is based upon the quantitation of the glucose residues joined by alpha 1,6 bonds introduced by varying amounts of branching enzyme. The procedure involved the synthesis of a polysaccharide from Glc-1-P and phosphorylase in the presence of the sample to be tested. The branched polysaccharide was then purified and the glucoses involved in the branching points were quantitated after degradation with phosphorylase and debranching enzymes. This method appeared to be useful, not only in enzymatic activity determinations but also in the study of the structure of alpha-D-glucans when combined with those of total polysaccharide quantitation, such as iodine and phenol-sulfuric acid.