Structural features of an anti-diabetic polysaccharide (TAP) from Tremella aurantia

The structure of an anti-diabetic polysaccharide (TAP) obtained from the fruiting bodies of Tremella aurantia was investigated by methylation analysis, Smith degradation, partial acid hydrolysis, 13C-NMR spectrometry, and enzymatic digestion. The results suggested that TAP was composed of (1-->3)-linked alpha-D-mannopyranosyl residues as a backbone, some of which were substituted at position 2 with (1-->3)-linked beta-D-xylopyranose side chains and with beta-D-glucopyransyluronic acid at position 4 linked to terminal alpha-D-mannopyranose.     

柘树根多糖的分离纯化及结构表征

以柘树[Cudrania tricuspidata(Carr.) Bur.]的根为材料, 经热水抽提、木瓜蛋白酶-Sevag法除蛋白、乙醇沉淀和DEAE-Sephadex A-50凝胶柱层析分离纯化, 得到一种水溶性的柘树根多糖(CPS-0). 采用HPLC、糖基组成分析、甲基化分析、GC、GC-MS、NMR(1H NMR, 13C NMR及HMQC)、元素分析、UV和IR等技术对CPS-0的纯度、性质、组成和结构进行表征. 结果表明, CPS-0仅含葡萄糖, 分子量为4.6×103, 主链由1,4-连接的α-D-葡萄糖残基组成, 其侧链由末端及1,4-连接的葡萄糖残基构成, 取代于主链分支点葡萄糖的6位, 平均每10个葡萄糖残基组成的重复单元中含有1个分支.     

Polysaccharides in fungi. XXIX. Structural features of two antitumor polysaccharides from the fruiting bodies of Armillariella tabescens.

An antitumor polysaccharide containing peptide moieties AT-HW ([alpha]D + 31 degrees in water) and an antitumor polysaccharide AT-AL ([alpha]D + 209 degrees in 1 M sodium hydroxide) were isolated from hot-water extract and the alkaline extract of the fruiting bodies of Armillariella tabescens, respectively. Chemical structures of AT-HW and AT-AL were investigated by a combination of chemical and spectroscopic methods. The results indicate that the major constituent of AT-HW (molecular weight, 105000), a heteroglycan, is composed primarily of beta-(1----6)-linked D-glucopyranosyl and D-galactopyranosyl residues, and contains their branched residues and terminal sugar (gluco-, manno-, and fucopyranose) residues, in addition to beta-(1----3)-linked D-glucopyranosyl residues, while AT-AL (molecular weight, 93000) is chiefly composed of alpha-(1----3)-linked D-glucopyranosyl residues.     

大粒车前子多糖组分PLP-1的结构表征

研究了由大粒车前子多糖分离纯化所得组分PLP-1的一级精细结构特征. 通过单糖组成分析、部分酸水解及甲基化分析,并结合NMR,GC和GC-MS等技术测定了PLP-1的一级结构. 结果表明,PLP-1由Ara（33.98%）,Xyl（58.23%）,Rha（2.36%）,Glc（2.23%）,Gal（2.36%）和Man（0.83%）组成,糖醛酸以GlcA形式存在. PLP-1中主要糖残基有α-T-linked Araf（9.58%）,β-T-linked Xylp（8.71%）,α-1,3-linked Araf（18.22%）,β-1,3-linked Xylp（8.05%）,β-1,4-linked Xylp（5.85%）,β-1,2,4-linked Xylp（16.98%）和β-1,3,4-linked Xylp（27.52%）,GlcA以α-T-linked GlcAp形式存在;此外还有1,2-linked Rhap,T-linked Glcp,1,6-linked Glcp,T-linked Galp,1,3-linked Galp和1,3,6-linked Galp等少量其它残基. 根据所得结果推断出PLP-1可能的一级结构.     

桑叶多糖SJB的结构分析和蛋白酪氨酸磷酸酯酶PTP1B抑制活性

通过DEAE-纤维素和凝胶过滤柱色谱对桑叶碱提粗多糖进行分级分离, 获得均一多糖SJB, 进行结构鉴定. 采用蛋白酪氨酸磷酸酯酶PTP1B体外模型对SJB进行降血糖活性测定. 结果表明: SJB的相对分子质量为5.4×104, 由鼠李糖、阿拉伯糖、葡萄糖、半乳糖、半乳糖醛酸组成的酸性杂多糖; 主链由1,2-、1,2,4-连接的鼠李糖和1,4-、1,3,4-连接的半乳糖醛酸组成; 侧链包括末端、1,5-、1,3,5-连接的阿拉伯糖; 末端、1,4-连接的葡萄糖以及末端、1,3-、1,4-、1,6-连接的半乳糖, 主要通过鼠李糖的O4位和半乳糖醛酸的O3位与主链相连. 该多糖为首次从桑叶中获得的酸性杂多糖. 20 μg/mL SJB对PTP1B的抑制率为31.7%.     

Separation, purification and structure elucidation of a polysaccharide from root of Cudrania tricuspidata

A water-soluble polysaccharide (CPS-0) was obtained from the root of Cudrania tricuspidata (Carr.) Bur., by hot water extraction (70°C), deproteination using enzymolysis and Sevag method, precipitation with ethanol, and fractionation through DEAE-Sephadex A-50 chromatography. The purity of CPS-0 was determined by HPLC and the structure was elucidated by monosaccharide composition analysis, methylation analysis, GC, GC-MS, NMR spectral (¹H-NMR, ¹³C-NMR, HMQC), UV, IR, and elemental analysis. The CPS-0 was found to contain glucose residues only. The average repeating unit is a decasaccharide having a backbone consisting of 1,4-linked α-D-glucopyranosyl residues to which the side chain consisting of terminal and 1,4-linked α-D-glucopyranosyl residues was attached at position 6 of the branching residues. __________ Translated from Chemical Journal of Chinese Universities, 2007, 28(6): 1088–1091 [译自: 高等学校化学学报]     

The major pectic arabinogalactan having activity on the reticuloendothelial system from the roots and rhizomes of Saposhnikovia divaricata

The major acidic polysaccharide, named saposhnikovan A, was isolated from the roots and rhizomes of Saposhnikovia divaricata. It showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test. It is composed of L-arabinose: D-galactose: D-galacturonic acid in the molar ratio of 6:15:10, and its molecular weight was estimated to be 54000. About 35% of the D-galacturonic acid residues exist as the methyl esters. Methylation analysis, 13C-nuclear magnetic resonance, and controlled Smith degradation studies indicated that the polysaccharide has the alpha-1----4-linked D-galacturonan backbone bearing alpha-1----5-linked L-arabino-beta-3,6-branched D-galactan side chains.     

Polysaccharides of Algae 71*. Polysaccharides of the Pacific brown alga <Emphasis Type="Italic">Alaria marginata</Emphasis>

The polysaccharide composition in sporophylls of the brown alga Alaria marginata enriched with laminaran and sulfated polysaccharides was studied. It was shown that laminaran molecules had an average degree of polymerization about 30 and consisted mainly of 3-linked β-D-glucopyranose residues, having no more than 10% of 1→6 linkages. The majority of chains (about 60%) were terminated at "reducing" end by mannitol residue. Alginic acid of sporophylls contained mannuronic (M) and guluronic (G) acids residues distributed along the linear polymer molecules as MM, MG, and GG blocks at a ratio of 4: 1: 1. Fucoidan was found to be composed of fucose, galactose, and sulfate as the major constituents, while xylose, mannose, glucuronic acid, and acetate were the minor components. It was shown that fucoidan contained two major components: fucan sulfate, molecules of which are built up of 3-linked fucopyranose residues with branches and sulfate groups at different positions, and fucogalactan, also containing chains of 3-linked fucopyranose residues with branches at positions 4 together with highly branched galactan chains terminated by fucose residues. The fucoidan contained also sulfated glucuronomannan and sulfated glucuronan as minor components.     

The substrate specificity of a glucoamylase with steroidal saponin-rhamnosidase activity from Curvularia lunata

In previous work, we studied and reported that an enzyme from Curvularia lunata 3.4381 had the novel specificity to hydrolyze the terminal rhamnosyl at C-3 position of steroidal saponin and obtained four transformed products; the enzyme was purified and ascertained as glucoamylase (EC 3.2.1.3 GA). In this work, the enzyme exhibiting steroidal saponin-rhamnosidase activity was systematically studied on 21 steroidal saponins and 6 ginsenosides. The results showed that the α-1,2-linked end-rhamnosyl residues at C-3 position of steroidal saponins could be hydrolyzed to corresponding secondary steroidal saponins, among which 18 compounds were isolated and identified, including 3 new secondary compounds. For the furostanosides having glucosyl residues at the C-26 position, hydrolysis occurred first at end-rhamnosyl at C-3 position to produce secondary furostanosides. The reaction of hydrolyzing glucosyl at C-26 position depended considerably on longer reaction times yielding the corresponding secondary spirostanosides (without rhamnosyl and glucosyl residues). The enzyme had the strict specificity for the terminal α-1,2-linked rhamnosyl residues of linear chain, or the terminal α-1,2-linked rhamnosyl residues with branched chain of 1,4-linked glycosyl residues of sugar chain at C-3 position of steroidal saponins, it was not specific for different aglycones, different glycons, and the number of glycon of sugar chain of steroidal saponin. The end-rhamnosyl of ginsenosides and p-nitrophenyl-α-l-rhamnopyranoside (pNPR) could not be hydrolyzed by the enzyme from C. lunata.     

Synthesis and conformational analysis of 6-C-methyl-substituted 2-acetamido-2-deoxy-beta-D-glucopyranosyl mono- and disaccharides

Several 6-C-substituted 2-acetamido-2-deoxy-beta-D-glucopyranosides (beta-D-GlcNAc monosaccharides 1a-3a and 1,4-linked disaccharides 1b-3b) were studied by solution NMR spectroscopy. Conformational analysis of the (6S)- and (6R)-C-methyl-substituted beta-d-GlcNAc monosaccharides indicates that the stereodefined methyl groups impose predictable conformational biases on the exocyclic C-5-C-6 bond, as determined by (1)H-(1)H and (13)C-(1)H coupling constants. Variable-temperature NMR experiments in methanol-d(4) were performed to determine DeltaDeltaH and DeltaDeltaS values derived from the two lowest energy conformers. These indicate that while the influence of 6-C-methyl substitution on conformational enthalpy is in accord with the classic principles of steric interactions, conformational preference in solution can also be strongly affected by other factors such as solvent-solute interactions and solvent reorganization.     

Sulfated Galactans of Champia indica and Champia parvula (Rhodymeniales,Rhodophyta) of Indian Waters

Sulfated galactans of the red seaweed species Champia indica and Champia parvula of Indian waters were extracted and purified by ion exchange chromatography. These were characterized by infrared and ¹³C NMR spectroscopy as well as by GC-MS analysis of alditol acetate derivatives produced by reductive hydrolysis/acetylation of sulfated and desulfated and their methylated samples. The sulfated galactans of these Champia species contained alternating β-(1→3)-linked galactopyranosyl units with sulfation at the 2-position and α-(1→4)-linked galactopyranosyl units having sulfation at both the 2- and 3-positions. Other minor substitutions included 6-O-methyl ether of the β-(1→3)-linked galactose residues only in Champia parvula.     

山茱萸酸性多糖FCP5-A的分离纯化与结构表征

从山茱萸中提取出水溶性粗多糖, 经柱色谱分离纯化得到一种酸性多糖组分FCP5-A. 采用高效凝胶渗透色谱法(HPGPC)测定其为均一性多糖, 平均分子量为8.7×104. 经IR、GC、部分酸水解、13C NMR及甲基化分析等方法对该多糖的化学结构进行了表征. 结果表明, 该多糖由鼠李糖、阿拉伯糖、半乳糖及半乳糖醛酸组成, 其摩尔比为1∶5.7∶0.6∶1.2. FCP5-A为多分支结构, 由-2)Rha(1-及-4)GalA(1-构成主链, 在鼠李糖的4位存在分支; 支链主要由高度分支的阿拉伯糖构成, 此外还存在-3)Gal(1-; 末端残基为Ara(1-及Gal(1-. 结果提示, FCP5-A为一种新的山茱萸酸性分支多糖.     

Constituents of seed of Malva verticillata. VII. Structural features and reticuloendothelial system-potentiating activity of MVS-I, the major neutral polysaccharide.

The structural features of MVS-I, the major neutral polysaccharide isolated from the seeds of Malva verticillata L., were elucidated by controlled Smith degradation, methylation analysis, partial acid hydrolysis and enzymic degradation studies. It has a backbone chain composed of beta-1,3-linked D-glucose and D-galactose residues having branches composed of alpha-1,5-linked L-arabinosyl beta-1,4-linked D-galactose and of beta-1,4-linked D-galactosyl beta-1,3-linked D-glucose residues at position 6 of a part of D-galactose units as side chains. MVS-I showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test.     

Isolation and structural characterisation of okara polysaccharides

Okara is a byproduct generated during tofu or soymilk production processes. Crude polysaccharide (yield 56.8%) was isolated by removing fat, protein and low molecular weight carbohydrates from initial okara. Crude okara polysaccharide was further divided into four soluble fractions and an insoluble residue fraction by extracting with 0.05 M EDTA + NH(4) oxalate, 0.05 M NaOH, 1 M NaOH and 4 M NaOH, with yields of 7.7%, 3.6%, 20.7%, 16.0% and 27.9%, respectively. Arabinose, galactose, galacturonic acid, xylose and glucose (only for the insoluble fraction) were the major constituent sugars. The primary sugar residues of okara polysaccharides were 1,4-linked β-galactopyranose, 1,5- and 1,3-linked α-arabinofuranose, 1,5-linked α-xylofuranose, 1,2-linked, 1,2,4-linked and terminal α-rhamnopyranose (or fucopyranose), and 1,4-linked β-glucopyranose (only for the insoluble fraction), indicating okara polysaccharides might contain galactan, arabinan, arabinogalactan, xylogalacturonan, rhamnogalacturonan, xylan, xyloglucan and cellulose.     

新型1,2,3-三唑类化合物的合成及抗菌构效关系

根据活性基团拼接原理, 以4-取代-苯胺为原料, 经重氮化、 关环和缩合反应合成了17个化合物1-(4-取代苯基)-5-取代苯基亚氨基-4-取代-1,2,3-三唑(7a~7c和13a~13d)和1-(4-取代苯基)-5-取代苄基氨基-4-取代-1,2,3-三唑(5a~5c, 10a~10c和14a~14d), 其中化合物5a~5c, 7b, 7c, 10a, 10c, 13b~13d和14b~14c为新化合物, 对所制备化合物的结构进行了表征. 生物活性测试结果表明, 所有化合物均表现出一定的抑菌活性, 对大肠杆菌的抑菌活性均优于氟康唑; 化合物7a和10c对金黄色葡萄球菌的抑制活性明显优于氟康唑; 而化合物13a和13d则对白色念球菌表现出良好的抑制活性, 与三氯生相当.     

Reticuloendothelial system-activating polysaccharides from rhizomes of Panax japonicus. I. Tochibanan-A and -B

From rhizomes of Panax japonicus (Araliaceae), two polysaccharides named tochibanan-A and -B, which show reticuloendothelial-potentiating activity in the carbon clearance test in mice, were isolated. The structure of tochibanan-A (molecular mass: 23,000) was elucidated as a linear beta-1,4-D-galactan. Tochibanan-B (molecular mass: 40,000) consists of D-galactose (87.1%), L-arabinose, D-glucose and D-galacturonic acid and has a beta-D-(1----4)-linked galactopyranosyl backbone possessing GalA-(1----6)-Gal, Ara-(1----5)-Ara, Gal, and Glc side chains. The structure around the branching points and the repeating unit were investigated and a possible structure of tochibanan-B is proposed.     

Structural Studies on Galactomannans From Brazilian Seeds

Abstract

Chemical structures of galactomannans from the native Brazilian species, M. scabrella, S. barbatiman and S. parahy-bum were studied. Their seeds, on aqueous extraction, furnished high yields of viscous galactomannans, whose mannose to galactose ratios were 1.1:1, 1.5:1, and 3.0:1, respectively. The polysaccharides were analysed by methylation, periodate oxidation and chromium trioxide oxidation. The results, confirmed by ¹³C NMR spectroscopy, indicated expected structures of legume galactomannans, namely a polymeric main chain of (l→4) -linked β-D-mannopyranosyl residues substituted at 0–6 by single unit α-D-galactopyranosyl side-chains. ¹³C NMR spectra showed clear splitting of the O-substituted resonances of C-4 of the β-D-mannosyl residues depending on the nearest-neighbour probabilities, indicating a random arrangement of the D-galactosyl groups in all of the three galactomannans.     

An acidic polysaccharide having immunological activities from the rhizome of Cnidium officinale.

An acidic polysaccharide, designated as cnidirhan AG, was isolated from the rhizomes of Cnidium officinale Makino. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 5.1 x 10(4). It showed pronounced reticuloendothelial system-potentiating activity in a carbon clearance test, and had a remarkable effect on both anti-complementary and alkaline phosphatase-inducing activities. It is composed of L-arabinose: D-galactose: D-glucuronic acid in the molar ratio of 2:6:1, in addition to small amounts of O-acetyl groups. Methylation analysis, carbon-13 nuclear magnetic resonance, controlled Smith degradation and limited acid hydrolysis indicated that the core structural features of cnidirhan AG include a backbone chain composed of beta-1,3-linked D-galactose residues. Some of the galactose units in the backbone carry beta-D-galactosyl side chains at position 6. Both alpha-L-arabinosyl arabinose side chains and terminal beta-D-glucuronic acid residues are linked to the core galactan units.     

用不保护或少保护的糖基受体合成寡糖*

用不保护或少保护的葡萄糖、甘露糖、鼠李糖作为糖基受体,经由糖原酸酯的中间体,能高区选和立体选地合成寡糖. α-(1→6)-连接的甘露寡糖、β-(1→6)-连接的葡萄寡糖、3,6-支化的甘露寡糖及葡萄寡糖用此方法能用很简单步骤合成,如具有重要生物活性的寡糖植保素激活剂葡萄六糖、具有抗肿瘤活性的香菇多糖的活性片段,以及一些具有重要生理功能的多糖的重复单元等.本文同时简述了用少保护的半乳糖和氨基葡萄糖为糖基受体合成寡糖的进展.     

Constituents of the seed of Malva verticillata. VIII. Smith degradation of MVS-VI, the major acidic polysaccharide, and anti-complementary activity of products.

The controlled Smith degradation of MVS-VI, the major acidic polysaccharide having remarkable anti-complementary activity isolated from the seeds of Malva verticillata L., was performed. Methylation analysis of both the primary and the secondary Smith degradation products indicated that the core structural features of MVS-VI include a backbone chain composed of beta-1,3-linked D-galactose residues. The majority of galactose units in the backbone carry side chains composed of beta-1,3- and beta-1,6-linked D-galactosyl residues at position 6. The controlled Smith degradation products showed considerable anti-complementary activity.