碱提水溶小皮伞多糖B3的研究

用ＧＣ,ＩＲ,ＮＭＲ,ＧＣ－ＭＳ及高碘酸氧化,Ｓｍｉｔｈ降解,甲基化分析,部分酸水解等方法确定了一个新的碱提水溶小皮伞多糖的一级结构,分子主链α－Ｄ－（１→４）。α－（ａ→６）Ｇｌｅ,且均连在主链的０－６上。     

山豆根木葡聚糖的研究

研究了山豆根中一种木葡聚糖的结构．用１ｍｏｌ／ＬＮａＯＨ提取,ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ－２５离子交换柱层析,Ｆｅｈｌｉｎｇ试剂分级得到山豆根木葡聚糖组分ＳＳｂ－１ＦＡ,用完全酸水解,甲基化分析,部分酸水解,三氧化铬氧化和１Ｈ,１３ＣＮＭＲ等方法对其结构进行研究．结果表明：ＳＳｂ－１ＦＡ的分子量为２．６×１０４,比旋光度［α］２０Ｄ＝＋１０．９°（ｃ０．２２,Ｈ２Ｏ）,由Ｌ－Ｆｕｃ,Ｄ－Ｘｙｌ,Ｄ－Ｇａｌ和Ｄ－Ｇｌｃ组成,摩尔比为：２．９２９．９７．５５９．８．ＳＳｂ－１ＦＡ由１→４连接的β－Ｄ－Ｇｌｃ残基构成主链,分枝有α－Ｄ－Ｘｙｌ（１→,β－Ｄ－Ｇａｌ（１→２）α－Ｄ－Ｘｙｌ（１→等类型,部分非还原末端由Ｌ－Ｆｕｃ（１→构成．     

树舌多糖Fb、Fc的结构研究

从树舌子实体中分离纯化出另两个级分Ｆｂ、Ｆｃ,经超速离心,电泳,ＳｅｐｈａｒｏｓｅＣＬ－４Ｂ柱层析等确定其均为质点、极性均一级分。经ＧＣ、ＩＯ＿４～－氧化,Ｓｍｉｔｈ降解,部分酸水解,甲基化及其产物ＧＣ,ＧＣ－ｍｓ分析,ＩＲ等分析确定Ｆｂ是由１→３甘露糖基构成主链,分枝点率及分枝率均较大;Ｆｃ由１→６和１→４甘露糖基构成主链,分枝点率及分枝率较少。     

化学修饰对金顶侧耳多糖抗病毒（CB_5）活性的影响

从金顶侧耳子实体中分离纯化一半乳甘露聚糖ＰＣ－３,其分子量约为６７ｋＤ,一级结构为α（１→６）糖苷键相连的Ｇａｌ构成分子的主链,部份残基Ｃ_２上带有分支,分支结构为α（１－２）Ｍａｎ－α（１－２）Ｍａｎ。按高碘酸氧化、部份酸水解,甲基化、硫酸化程序对ＰＣ－３的结构进行化学修饰;并分别将ＰＣ－３及其衍生物与柯萨奇病毒Ｂ_５进行体外实验,结果表明,ＰＣ－３经硫酸化后,显著地提高了抗病毒活性;而高碘酸氧化,甲基化,部份酸水解产物则降低了抗ＣＢ_５的活性。     

金顶侧耳多糖PC—4的结构确定与抗肿瘤活性的研究

３％氯乙酸浸提过的金顶侧耳子实体中分离纯化另一水溶性多糖ＰＣ－４。该多糖分子量经为１８９ｋＤ。纸层析与气相层析分析表明其为单一聚糖。经高磺酸氧化,Ｓｍｉｔｈ降解,甲基化,层析,气质联机分析,核磁其振（Ｈ－ＮＭＲ,１３Ｃ－ＮＭＲ）谱及红外光谱测定等,可确定Ｃ－４的主链结构由β－（１→３）糖苷键相连的葡萄糖构成,部份残基Ｃ６,上带有分支。约每５个糖残基有两个侧链,侧链仅为１个葡萄糖残基。     

树舌多糖Fb、Fc的结构研究

从树舌子实体中分离纯化出另两个级分Ｆｂ、Ｆｃ经超速离心,电泳,ＳｅｐｈａｒｏｓｅＣＬ－４Ｂ柱层析等确定其均为质点、极性均一级分。经ＧＣ、ＩＯ４＾－氧化,Ｓｍｉｔｈ降解,部分酸水解,甲基化及其产物ＧＣ、ＧＣ－ｍｓ分析,ＩＲ等分析确定Ｆｂ是由１→６和１→４甘露糖基构成主链,分枝点率及分枝率较少。     

滇重楼地上部分的配糖体

从滇重楼ＰａｒｉｓｐｏｌｙｐｈｙｌｌａＳｍ．ｖａｒ．ｙｕｎｎａｎｅｎｓｉｓ（Ｆｒ．）Ｈ－Ｍ,地上部分,分离出４个微量的配糖体,经光谱分析和化学降解证明其化学结构分别为２５Ｓ－异钮替皂甙元－３－Ｏ－α－Ｌ－鼠李吡喃糖基（１→２）［α－Ｌ－鼠李吡喃糖基（１→４）］－β－Ｄ－葡萄吡喃甙（Ａ）,２６－β－Ｄ－葡萄吡喃糖基－纽替皂甙元－３－Ｏ－α－Ｌ－鼠李吡喃糖基（１→２）［α－Ｌ－鼠李吡喃糖基（１→４）－β－Ｄ－葡萄吡喃糖甙（Ｂ）,山奈酚－３－Ｏ－β－Ｄ－葡萄吡喃糖基（１→６）－β－Ｄ－葡萄吡喃甙（Ｃ）,７－Ｏ－α－Ｌ－鼠李吡喃糖基－山奈酚－３－Ｏ－β－Ｄ－葡萄吡喃糖基（１→６）－β－Ｄ－葡萄糖甙（Ｄ）。     

眼镜王蛇蛇毒神经毒素CM—11二级结构单元的判定

眼镜王蛇毒液抽提物ＣＭ－１１为含７２个残基的长链神经毒素,对其进行了ＤＱＦ－ＣＯＳＹ,ＴＯＣＳＹ和ＮＯＥＳＹ等一系列２Ｄ－ＮＭＲ谱测定,通过系统地分析各种ＮＯＥ信息,化学位移的分布等数据推测了蛋白质有规律二级结构,最后利用ＭＣＤ主链引导法确定它的二级结构,其中有三段反平行β折叠股（Ｉ２０～Ｗ２６,Ｒ３７～Ａ４３和Ｖ５３～Ｓ５９）,一段α螺旋构象（Ｗ３０～Ｇ３５）和四个可能的转角（Ｐ７～Ｋ１０,Ｃ１     

低氧对肺动脉内皮细胞PDGF—B链释放及平滑肌细胞生长的影响

应用蛋白ｄｏｔｂｌｏｔ技术检测了低氧内皮细胞条件培养液（ＨＥＣＣＭ）和常氧内皮细胞条件培养液（ＮＥＣＣＭ）内ＰＤＧＦ相对含量,并利用［３Ｈ］－ＴｄＲ掺入法和流式细胞术观察了ＨＥＣＣＭ和ＮＥＣＣＭ及加入特异ＰＤＧＦ抗体对肺动脉平滑肌细胞（ＰＡＳＭＣ）生长的影响。结果表明,ＨＥＣＣＭ中的ＰＤＧＦ含量明显高于ＮＥＣＣＭ;ＨＥＣＣＭ能明显增强ＰＡＳＭＣ内ＤＮＡ合成,促进ＰＡＳＭＣ从Ｇｏ／Ｇ１期进入Ｓ期;当预先加入ＰＤＧＦ－Ｂ链抗体时,则会明显地抑制ＨＥＣＣＭ对ＰＡＳＭＣ的ＤＮＡ合成,阻止ＰＡＳＭＣ从Ｇｏ／Ｇ１期进入Ｓ期。结果提示,低氧时ＰＡＳＭＣ增殖与肺动脉内皮细胞分泌释放ＰＤＧＦ增加有关     

化学修饰对金顶侧耳多糖抗病毒（CB5）活性的影响

从金侧耳子实体中分离纯化一半乳甘露聚糖ＰＣ－３,其分子量约为６７ＫＤ,一级结构ａ（１→６）糖苷键相连的Ｇａｌ构成分子的主链,部份残基Ｃ２上带有分支,分支结构为ａ（１－２）Ｍａｎ－ａ（１－２）Ｍａｎ。按高碘酸氧化、部份酸水解、甲基化、硫酸程序对ＰＣ－３的结构进行化学修饰;并分别将ＰＣ－３及其衍生物与柯萨厅病毒Ｂ５进行体外实验,结果表明,ＰＣ－３经硫酸化后,显著地提高了抗病毒活性;而高碘酸氧化,甲基化     

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。     

Action of alpha-1,6-glucan glucohydrolase on oligosaccharides derived from dextran

The action of α-1,6-glucan glucohydrolase on α-(1→6)-D-glucosidic linkages in oligosaccharides that also contain an α-(1→2)-, α-(1→3)-, or α-(1→4)-D-glucosidic linkage has been investigated. The enzyme could hydrolyse α-(1→6)-D-glucosidic linkages from the non-reducing end, including those adjacent to an anomalous linkage. α-(1→6)-D-Glucosidic linkages at branch points were not hydrolysed, and the enzyme could neither hydrolyse nor by-pass the anomalous linkages. These properties of α-1,6-glucan glucohydrolase explain the limited hydrolysis of dextrans by the exo-enzyme. Hydrolysis of the main chain of α-(1→6)-D-glucans will always stop one D-glucose residue away from a branch point. The extent of hydrolysis by α-1,6-glucan glucohydrolase of some oligosaccharide products of the action on dextran of Penicillium funiculosum and P. lilacinum dextranase, respectively, has been compared. Differences in the specificity of the two endo-dextranases were revealed. The Penicillium enzymes may hydrolyse dextran B-512 to produce branched oligosaccharides that retain the same 1-unit and 2-unit side-chains that occur in dextran.     

Growth-inhibitory activity of the d-mannan of saccharomyces cerevisiae X2180-1A-5 mutant strain against mouse-implanted sarcoma 180 and ehrlich-carcinoma solid tumor

The d-mannan of Saccharomyces cerevisiae X2180-1A-5 mutant strain, which possesses a main chain composed of α-(1→6) linked d-mannopyranosyl residues and a small proportion of branches composed of α-(1→2)- and α-(1→3)-linked d-mannopyranosyl residues, showed strong growth-inhibitory activity against mouse-implanted Sarcoma 180 and Ehrlich-carcinoma solid tumor. The observation that the level of this activity was nearly identical with that of the d-mannan of a wild-type strain of bakers' yeast, which possesses a high proportion of branches composed of α-(1→2)- and α-(1→3)-linked d-mannopyranosyl residues, suggests that the branches are not essential for antitumor activity. The partial acid-degradation products of both d-mannans, the molecular weight of which was one-third of that of each parent d-mannan, had only one half of the antitumor activity of the parent d-mannans. This suggests that molecular size is the most important factor for the differences in activity of the polysaccharides of wild and mutant strains.     

Glycans from streptococcal cell-walls: the molecular structure of an antigenic diheteroglycan of D-glucose and L-rhamnose from Streptococcus bovis

The monosaccharide sequence and glycosidic bond-types have been determined for an antigenic diheteroglycan of D-glucose and L-rhamnose from the cell wall of Streptococcus bovis, strain C3, by use of an integrated analytical scheme based on methylation analysis, periodate oxidation, oxidation with chromium trioxide, enzymic hydrolysis, and chemical degradation. A typical molecule of the glycan consists of a main chain of L-rhamnosyl residues and isomaltose side-chains, with 16 repetitions of the structure, -α-L-rhamnosyl-(1→3)-[α-D)-glucosyl-(1→6)-α-D-glucosyl-(1→2)]-α-L-rhamnosyl-(1→2)-α-L-rhamnosyl-, linked alternately by α-L-(1→3) and α-L-(1→2) linkages. The isomaltose side-chains of the glycan are the immunodeterminant groups. The new antigenic glycan is ideally suited for use in the preparation of anti-isomaltose antibodies, which should be of value in the detection of other antigens having isomaltose determinants.     

Structural studies of plant gum from sap of the lac tree, Rhus vernicifera

The plant gum isolated from sap of the lac tree, Rhus vernicifera (China), was separated into two fractions having mol. wt. 84,000 and 27,700 by aqueous-phase gel-permeation chromatography. The fractions contain d-galactose (65 mol%), 4-O-methyl-d-glucuronic acid (24 mol%), d-glucuronic acid (3 mol%), l-arabinose (4 mol%), and l-rhamnose (3 mol%). Smith degradation of the carboxyl-reduced polysaccharides gives products of halved molecular weight, and these consist of a β-(1→3)-linked galactopyranan main chain and side chains made up of galactopyranose residues. Peripheral groups, such as α-d-Galp-, α-d-Galp-(1→6)-β-d-Galp-, 4-O-methyl-β-d-GlcpA-, and 4-O-methyl-β-d-GlcpA-(1→6)-β-d-Galp-, are attached to this interior core through β-(1→3)- or β-(1→6)-linkages.     

Étude complémentaire de la structure de trois galactoxyloglucanes (amyloïdes) de graines

D-Galacto-D-xylo-D-glucans (amyloids) from Balsamina, Tropaeolum, and Tamarindus seeds behave in a similar manner in the presence of various glycosidase preparations: slow depolymerization by enzymes from several germinated or non-germinated seeds, and hydrolysis into monosaccharides and oligosaccharides by commercial cellulase and hemicellulase preparations from fungi. A purified cellulase from Penicillium notatum gave a dialyzable fraction almost exclusively composed of α-D-xylopyranosyl-(1→6)-D-glucose residues and a nondialyzable fraction composed of chains of β-D-(1→4)[withsome (1→3)]-glucopyranosyl residues; β-D-galacto-pyranosyl-(1→2)-α-D-xylosyl groups are linked to some of the β-D-glucosyl residues at 0-6. The presence of (1→3)-linkages in the D-glucan chain of the Balsamina was verified by methylation and sequential periodate oxidation-borohydride reduction; the distribution of the substituents on the D-glucan chain is not regular. The main D-glucan backbone, where the β-D-glucosyl residues are partly linked at 0-6 to β-D-galactosyl-(1→2)-D-xylosyl groups, is linked to D-glucan chains where almost all the D-glucose units are linked at 0-6 by one α-D-xylosyl group. The presence of 3,6-di-O-methyl-D-glucose after permethylation and hydrolysis suggests that the xyloglucan chains are linked to 0-2 of the D-glucosyl units of the galactoxyloglucan backbone.     

Immobilization of Chloroplast Photosystems

Highly branched α-glucan molecules exhibit low digestibility for α-amylase and glucoamylase, and abundant in α-(1→3)-, α-(1→6)-glucosidic linkages and α-(1→6)-linked branch points where another glucosyl chain is initiated through an α-(1→3)-linkage. From a culture supernatant of Paenibacillus sp. PP710, we purified α-glucosidase (AGL) and α-amylase (AMY), which were involved in the production of highly branched α-glucan from maltodextrin. AGL catalyzed the transglucosylation reaction of a glucosyl residue to a nonreducing-end glucosyl residue by α-1,6-, α-1,4-, and α-1,3-linkages. AMY catalyzed the hydrolysis of the α-1,4-linkage and the intermolecular or intramolecular transfer of maltooligosaccharide like cyclodextrin glucanotransferase (CGTase). It also catalyzed the transfer of an α-1,4-glucosyl chain to a C3- or C4-hydroxyl group in the α-1,4- or α-1,6-linked nonreducing-end residue or the α-1,6-linked residue located in the other chains. Hence AMY was regarded as a novel enzyme. We think that the mechanism of formation of highly branched α-glucan from maltodextrin is as follows: α-1,6- and α-1,3-linked residues are generated by the transglucosylation of AGL at the nonreducing ends of glucosyl chains. Then AMY catalyzes the transfer of α-1,4-chains to C3- or C4-hydroxyl groups in the α-1,4- or α-1,6-linked residues generated by AGL. Thus the concerted reactions of both AGL and AMY are necessary to produce the highly branched α-glucan from maltodextrin.     

Water- and alkali-soluble glucans from oak lichen

A water-soluble glucan, [α]²_D +217° (water), and an alkali-soluble glucan,

+152° (sodium hydroxide), have been isolated from the oak lichen Evernia prunastri (L.) Ach. On the basis of methylation analysis, periodate oxidation, and partial acid hydrolysis, the water-soluble polysaccharide has been shown to be a neutral, slightly branched glucan with a main chain composed of (1→3)- and (1→4)- linked glucopyranose residues in the ratio 1?:1. Branching occurs most probably at position 2 of (1→4)-linked glucopyranose residues. On the basis of optical rotation and i.r. spectral data, and enzymic hydrolysis, the α-D configuration has been assigned to the glycosidic linkages. Likewise, the alkali-soluble polysaccharide was shown to be a neutral, branched glucan with a main chain composed of (1→3)- and (1→4)-linked α-D-glucopyranose residues in the ratio 6:1. Each of the (1→4)-linked units was a branch point involving position 6. The presence of some β-D linkages is not excluded since hydrolysis with β-D-glucosidase occurred to a small extent.     

Purification and characterization of highly branched α-glucan-producing enzymes from Paenibacillus sp. PP710

Highly branched α-glucan molecules exhibit low digestibility for α-amylase and glucoamylase, and abundant in α-(1→3)-, α-(1→6)-glucosidic linkages and α-(1→6)-linked branch points where another glucosyl chain is initiated through an α-(1→3)-linkage. From a culture supernatant of Paenibacillus sp. PP710, we purified α-glucosidase (AGL) and α-amylase (AMY), which were involved in the production of highly branched α-glucan from maltodextrin. AGL catalyzed the transglucosylation reaction of a glucosyl residue to a nonreducing-end glucosyl residue by α-1,6-, α-1,4-, and α-1,3-linkages. AMY catalyzed the hydrolysis of the α-1,4-linkage and the intermolecular or intramolecular transfer of maltooligosaccharide like cyclodextrin glucanotransferase (CGTase). It also catalyzed the transfer of an α-1,4-glucosyl chain to a C3- or C4-hydroxyl group in the α-1,4- or α-1,6-linked nonreducing-end residue or the α-1,6-linked residue located in the other chains. Hence AMY was regarded as a novel enzyme. We think that the mechanism of formation of highly branched α-glucan from maltodextrin is as follows: α-1,6- and α-1,3-linked residues are generated by the transglucosylation of AGL at the nonreducing ends of glucosyl chains. Then AMY catalyzes the transfer of α-1,4-chains to C3- or C4-hydroxyl groups in the α-1,4- or α-1,6-linked residues generated by AGL. Thus the concerted reactions of both AGL and AMY are necessary to produce the highly branched α-glucan from maltodextrin.     

Characterization of a water-soluble glucan from angelica acutiloba

A water-soluble glucan, AR-Glucan, from the roots of Angelica acutiloba was obtained homogeneous as determined by ultracentrifugal analysis, electrophoresis, and gel filtration. AR-Glucan was composed Of d-glucose, and its MW was estimated to be 13 500. Methylation analysis indicated that AR-Glucan contained 4-O- and 4,6-di-O-substituted glucosyl residues. ¹H and ¹³C NMR data accorded with the results of methylation analysis, and the glycosidic linkages in AR-Glucan were shown to have the α-configuration. The results of β-amylase, α-amylase, and pullulanase treatments of AR-Glucan showed that it contained (1 → 4) linked α-d-glucosyl side chains of long chain length such as amylopectin. Thus, AR-Glucan is a (1 → 4) linked α-d-glucan to which are attached glucosyl side chains at O-6 of the glucosyl residues of the main chain.