猴头菌水溶性多糖的分离纯化与结构表征

从猴头菌子实体中分离得到一种新型的水溶性杂多糖HEPF2,分子量大小为1.66′104Da,该多糖由岩藻糖、半乳糖和葡萄糖以1.00:3.69:5.42比例构成,同时也含有微量的3-O-甲基鼠李糖。进一步利用傅立叶变换红外光谱法、糖组成分析、甲基化分析、部分酸水解法和核磁共振法等方法进行结构鉴定,检测结果表明,该杂多糖中包含1→4、1→6结合的葡萄糖和1→6结合的半乳糖残基,连接于主链的侧链残基,包括岩藻糖残基、少数的端基葡萄糖和半乳糖残基。核磁共振法检测结果还表明,1→4结合葡萄糖为β构型,(1→6)结合半乳糖、(1→2,6)结合半乳糖和端基葡萄糖均为α构型。     

茶多糖TGC的结构表征

采用气相色谱-质谱联用技术(GC-MS)分析均一茶多糖TGC的单糖组成, 并与NMR, 圆二色谱、紫外扫描等其他分析方法结合, 对茶多糖TGC的一级结构及其在溶液中的构象加以探讨. 结果表明: 茶多糖TGC是由鼠李糖、阿拉伯糖、木糖、葡萄糖、甘露糖和半乳糖等6种单糖组成, 它在水溶液中应以有序的螺旋构象存在, 其一级结构为: 主链的骨架结构由鼠李糖、葡萄糖和半乳糖构成, 这3种单糖都有可能连接支链, 不接支链时其连接方式为β1→3, 支链主要由阿拉伯糖构成, 其连接方式可为β1→2, β1→3, β2→3三种, 木糖以β1→存在于主链和支链的末端.     

碱液提取箬叶多糖的纯化及其结构性质的研究

通过高碘酸氧化、Smith降解、部分酸水解分析、NMR分析等多种方法对以不同浓度的NaOH溶液箬叶中提取的两种多糖FⅢ-a及FⅣ-a进行了研究,结果表明二者均具有多分枝结构,FⅢ-a主链以α(1→3)连接的木糖为主,分子侧链由半乳糖、阿拉伯糖、葡萄糖醛酸构成,葡萄糖醛酸主要位于分子的末端;FⅣ-a主链由α(1→3)木糖和β(1→6)半乳糖构成,以阿拉伯糖、葡萄糖醛酸组成侧链,葡萄糖醛酸主要位于分子的末端.     

凉粉草胶的初级结构与流变性质的研究

凉粉草胶经过DEAE-Sepharose FF分离可以得到中性糖和酸性糖两种组分,其中中性糖的尖峰分子量Mp为5227,酸性糖的尖峰分子量为6566,前者的单糖组成(以摩尔百分比计)为半乳糖:葡萄糖:甘露糖:木糖:阿拉伯糖:鼠李糖=9.9∶15.3∶4.31∶1.48∶11.6∶1,后者的单糖组成为半乳糖:葡萄糖:甘露糖:木糖:阿拉伯糖:半乳糖醛酸:鼠李糖=2.66∶1∶0.37∶2.29∶12.5∶23.5∶5.99。两者再经Sephadex G-100凝胶色谱分离,均为单一对称峰,酸性糖经琼脂糖凝胶电泳,甲苯胺蓝显色为均一斑点,表明所分离得到的两种组分都为均一组分。紫外光谱分析表明两种糖都不含蛋白质或肽段,红外光谱分析表明NMBG和AMBG都具有多糖特征吸收峰,NMBG仅在872 cm-1附近有吸收峰,表明其结构中只有β-糖苷键,AMBG在896和858 cm-1附近有吸收峰,表明其结构中既有β-糖苷键,又有α-糖苷键。流变学实验表明在1%~5%(w/w)内中性糖不具有流变学性质,但酸性糖却表现出明显地流变学性质。     

人参叶水溶性多糖——杂多糖P_N的纯化与结构初步确定

 从人参叶中提取的水溶性多糖经分离纯化得杂多糖P_N。P_N的分子量约为190万,单糖组成为阿拉伯糖、鼠李糖、木糖、半乳糖醛酸、半乳糖、葡萄糖及少量未知糖,单糖的摩尔比依次为8.1:0.8:1.0:1.6:12.5:4.1(未知糖除外)。经超离心分析,琼脂糖4B柱分析,玻璃纤维纸电泳和醋酸薄膜电泳鉴定等证明P_N为均一组份。经果胶酶降解,部分酸水解,高碘酸盐氧化,Smith降解,甲基化及其产物气相色谱(GLC)、气相色谱-质谱联用(GLC-MS)等结构分析表明P_N为多分支结构,分子的主链主要是由β-(1→3)连接的半乳糖组成,并在4—0和6—0上带有分支,平均每三个半乳糖有二个分支。     

地生枝顶孢胞外多糖的理化性质和结构初步分析

报道分离自地生枝顶孢Acremonium terricola RCEF0260菌株发酵滤液中的胞外多糖EPS-Ia的理化性质和一级结构。EPS-Ia分子量为416kD,至少含有D-甘露糖、D-葡萄糖、D-半乳糖、D-阿拉伯糖、D-木糖,各单糖摩尔比为4.46: 0.24: 2.38: 0.90: 0.19。糖醛酸含量为27.4%。硫酸基含量0.92%、蛋白质含量2.23%。氨基酸组成分析显示:EPS-Ia中含有17种常见氨基酸。EPS-Ia为型吡喃糖,含有1→3糖苷键,1→6糖苷键及1→2糖苷键,其中的糖肽键是N-糖苷键。     

高相对分子质量裂褶多糖的制备与结构鉴定

以裂褶菌（Schizophyllum commune）发酵生产的培养物为研究对象,经过活性炭脱色、Sevag法脱杂蛋白、乙醇沉淀得粗多糖,再经Sephadex G-200柱层析分离纯化得裂褶多糖纯品.通过Sephadex G-200凝胶层析法测得其平均分子质量为436kDa;由气相色谱、红外光谱、高碘酸氧化、Smith降解、^13C核磁共振等方法表征其化学结构,推测其结构为具有（1→6）分支的β-〔1-3）-D-葡聚糖：其组成重复单元应该含有3个主链糖基和一个单糖分支,主链的取代发生在C-1和C-3之间,即为1→3糖苷键;分支发生在C-1和C-6之间,即为1→6糖苷键,其中分支点在主链糖基的C-6上.     

蛹虫草胞外多糖的研究 Ⅰ.半乳甘露聚糖(CM-I)的纯化和结构研究

从蛹虫草菌体培养液中提取水溶性粗多糖经分离纯化,得一种含有少量蛋白的半乳甘露聚糖CM-Ⅰ,分子量2.7×10~4,[α]_D~(19)=+54.7°。糖组成摩尔比,半乳糖:甘露糖=6∶5。经高碘酸氧化,Smith降解,部分酸水解,半乳糖苷酶解,~1H-NMR分析,完全甲基化与GC及GC-MS分析,证明:多糖CM-Ⅰ具有高度分枝结构,其以β-(1→2)连接的甘露糖为主干,枝链由较大量的β-(1→6)半乳糖和较大量的β-(1→2)呋喃半乳糖构成,分别连接在主干的0—4和0—6上。     

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。     

南瓜多糖的单糖组成及其生理效应

南瓜多糖是南瓜中重要的活性成分,由葡萄糖、半乳糖、阿拉伯糖、葡萄糖醛酸等单糖组成,是一类主链上含有β-1,3糖苷键、侧链含有α-糖苷键的杂多糖。南瓜多糖具有降血糖、调理血脂、抑制肿瘤、抗氧化等生理作用。本文对南瓜多糖的化学组成和生理效应进行了综述,最后,对南瓜多糖的研究方向进行了展望。     

草苁蓉根、茎水溶性多糖BRT的结构特征

本文以长白山区珍贵野生药用植物草苁蓉为研究对象 .草苁蓉又名“不老草” ,具有滋补强壮、益寿延年之功及补肾壮阳、润肠止血之效 ,为国家三级重点保护植物[1] .近年的研究发现 ,草苁蓉醇提物不仅可以清除体内的游离基 ,而且还可以显著增强机体的免疫能力 ,同时对草苁蓉化学成分的研究也在逐步深入[2 ] ,但对于草苁蓉多糖的系统研究尚未见报道 .为了更全面地认识和利用草苁蓉这一珍贵的植物资源 ,同时也为探讨多糖的结构与功能的关系 ,本文对草苁蓉根、茎的水溶性多糖ＢＲＴ组分进行了结构测定方面的研究 .1　材料和方法1 1　材料为本研究…     

Degradation of unsaturated polysaccharide derived from acidic polysaccharide of Fusarium sp. M7-1 by a bacterium isolated from soil

A soil bacterium, strain no. 19, capable of using unsaturated polysaccharide derived from acidic polysaccharide of Fusarium sp. M7-1 as a sole source of carbon was isolated. The bacterium degraded about 70% of the total sugar content. Results from analysis of the degraded polysaccharide showed that the bacterium degraded the β(1→6) galactofuranoside linkage as well as the unsaturated glucuronic acid residues linked to the galactofuranoside residues via the α(1→2) linkage.     

Structural Analysis of the Extracellular Polysaccharide Produced by Sphaerotilus natans

An extracellular polysaccharide (EPS) was recovered and purified from the culture fluid of a sheathed bacterium, Sphaerotilus natans. Glucose, rhamnose, and aldobiouronic acid were detected in the acid hydrolysate of EPS by thin-layer chromatography (TLC). The aldobiouronic acid was found to be composed of glucuronic acid and rhamnose by TLC and gas-liquid chromatography analyses of the corresponding neutral disaccharide. The structure of EPS was identified by methylation linkage analysis and nuclear magnetic resonance. Additionally, partial acid hydrolysates of EPS were prepared and put through fast atom bombardment-mass spectrometry to determine the sugar sequence of EPS. The resulting data showed that EPS produced by S. natans is a new gellan-like polysaccharide constructed from a tetrasaccharide repeating unit, as shown below.

→4)-α-D-Glcp-(1→2)-β-D-GlcAp-(1→2)-α-L-Rhap- (1→3)-β-L-Rhap-(1→     

东北红豆杉多糖的化学研究

利用水提醇沉提取东北红豆杉多糖TP,经超滤得到超滤外液TP-1和内液TP-2。TP-2进行部分酸水解和凝胶柱层析分离纯化,得到TP-2-1a。通过对理化性质、分子量、单糖组成和甲基化测定结果分析,确定其分子量分布在7.0 kDa左右,糖组成由Rha、Man、Gal、Glu、GalA和GlcA构成,摩尔比为:16.9∶1.0∶15.5∶1.3∶9.9∶2.5,中性糖以Gal的1→3、1→4连接为主,在1→3连接的O-6位上有分支;Rha以1→2连接为主,在O-4位上有分支;Man以1→4、1→6连接为主;Glu以1→3、1→4连接为主;非还原末端主要是Gal及少量的Man、Glu和Rha。酸性糖以1→4连接GalA为主,无分支。该多糖为首次从东北红豆杉中分离得到。     

安络小皮伞中水溶性多糖的研究——Ⅰ.甘露聚糖 FP_1 的纯化与结构研究

从安络小皮伞水溶性多糖中分离纯化得一甘露聚糖 FP_1。分子量约为24万。经红外光谱、~+H-NMR 谱和亲和层析指明为β-甘露聚糖。结构分析采用高碘酸氧化、Smith 降解、完全甲基化 GC、GC-MS 与~(13)C-NMR 分析,分子的主链是β-D-(1→6)连接的甘露糖,支链为β-(1→3),β(1→2)甘露糖,分别连接在主链的 O-3和 O-2上。     

Structural investigations on the non-starchy polysaccharides of oat bran

Digestion of oat bran with hog pancreatic α-amylase to hydrolyze starch (～50%) results in solubilization of much β-d-glucan (9%) which is the main non-starchy polysaccharide. This soluble β-d-glucan has been shown by methylation analysis and specific enzymic hydrolysis to contain linear chains with (1→3) and (1→4) linkages in the proportions 1 : 2·6. Compositional and linkage analysis studies on the water-insoluble residue have shown the presence of further β-d-glucan (5%) and arabinoxylan (3%), but only traces of cellulose (<0·5%).     

Structure of l-arabino-d-galactan-containing glycoproteins from radish leaves

Two l-arabino-d-galactan-containing glycoproteins having a potent inhibitory activity against eel anti-H agglutinin were isolated from the hot saline extracts of mature radish leaves and characterized to have a similar monosaccharide composition that consists of l-arabinose, d-galactose, l-fucose, 4-O-methyl-d-glucuronic acid, and d-glucuronic acid residues. The chemical structure features of the carbohydrate components were investigated by carboxyl group reduction, methylation, periodate oxidation, partial acid hydrolysis, and digestion with exo- and endo-glycosidases, which indicated a backbone chain of (1→3)-linked β-d-galactosyl residues, to which side chains consisting of α-(1→6)-linked d-galactosyl residues were attached. The α-l-arabinofuranosyl residues were attached as single nonreducing groups and as O-2- or O-3-linked residues to O-3 of the β-d-galactosyl residues of the side chains. Single α-l-fucopyranosyl end groups were linked to O-2 of the l-arabinofuranosyl residues, and the 4-O-methyl-β-d-glucopyranosyluronic acid end groups were linked to d-galactosyl residues. The O-α-l-fucopyranosyl-(1→2)-α-l-arabinofuranosyl end-groups were shown to be responsible for the serological, H-like activity of the l-arabino-d-galactan glycoproteins. Reductive alkaline degradation of the glycoconjugates showed that a large proportion of the polysaccharide chains is conjugated with the polypeptide backbone through a 3-O-d-galactosylserine linkage.     

Strucrural investigation of Klebsiella serotype K7 polysaccharide

Methylation analysis of and partial hydrolysis studies on the Klebsiella K7 capsular polysaccharide and its carboxyl-reduced derivative indicated the recurrence of D-glucopyranuronic acid, D-mannopyranose, and D-glucopyranose residues, linearly linked in a specific manner, in the molecular structure. D-Galactopyranose and pyruvic acid residues are linked to the main chain on the D-mannose residues (at O-3) and the D-glucose residues (at O-4 and O-6), respectively; the simplest interpretation of this evidence is that nine sugar residues and pyruvic acid constitute a repeating unit. The sequence →3)-β-D-GlcAp-(1→2)-α-D-Manp-(1→2)-α-D-Manp-(1→3)-D-Glcp→ was demonstrated by the isolation from the polysaccharide of an aldotetraouronic acid of this structure.     

13C NMR structural investigation of scleroglucan

This paper concerns the ¹³C NMR signal assignment in the DMSO of a neutral polysaccharide, scleroglucan. The previously proposed chemical structure is confirmed. The ¹³C NMR spectrum shows that scleroglucan is a regular poly (A, B, C, D) type glucan. The relaxation times of the different series of carbon atoms demonstrate that a single, pendant glucose group is attached to each third monomer along the main chain of what is a β(1 → 3)-glucan. Partial acid hydrolysis gives a spectrum analogous to that of the β(1 → 3)-d-glucan, curdlan, and confirms the structure of the polymer backbone.In aqueous solution, no signal has been obtained due to the existence of a rigid, ordered conformation as demonstrated by optical rotation; in the presence of sodium hydroxide, a conformational transition is produced just as with curdlan. The conclusion is that the behaviour of scleroglucan in solution is similar to that of other β(1 → 3)-d-glucans even though it is more soluble.     

Primary structure and configuration of tea polysaccharide

Polysaccharide is a class of natural macromole-cules of which many species have been found to carry significant biological activities. Although the research on activities of saccharide has been at a lower level in the past comparing to those of proteins and nucleic acids, much progress has been made in recent years because of accelerated activities worldwide[1]. Such progress has been made mostly in areas of structural analysis, and researches on structure-activity relation-ships. The biologic…