白骨壤酸性果胶多糖HAM-3-Ⅱb-Ⅱ的结构分析

以分离纯化得到的白骨壤酸性多糖HAM-3-Ⅱb-Ⅱ为研究对象, 采用高碘酸氧化-Smith降解、部分酸水解以及甲基化分析等技术对该多糖的结构进行分析. 结果表明, HAM-3-Ⅱb-Ⅱ为典型的鼠李半乳糖醛酸聚糖I 型酸性果胶类多糖, 主链骨架包括: 1,4-连接的α-D-GalpA构成的无分支的半乳糖醛酸聚糖(光滑区)和通过α-D-GalpA的O4位与1,2-和1,2,4-L-Rhap的O2交替相连构成的含有较多分支的鼠李半乳糖醛酸聚糖(毛发区). 由T-、1,6-、1,3,6-、1,4-、1,4,6-D-Galp和T-、1,2-、1,3-、1,5-、1,2,5-、1,3,5-Aaraf聚合成的AGⅠ型阿拉伯半乳聚糖、AGⅡ型阿拉伯半乳聚糖、半乳聚糖以及阿拉伯聚糖, 构成了HAM-3-Ⅱb-Ⅱ的侧链部分, 通过Rha残基的O4位与主链相连.     

当归多糖ASP3及其水解产物的NMR光谱分析

对当归多糖ASP3的糖链结构进行分析. 分别采用0.2 mol/L三氟乙酸(Trifluoroacetic acid, TFA)和内切-α-(1→4)-聚半乳糖醛酸酶(EndoPG)对ASP3进行部分酸水解和酶水解, 并对水解前后多糖组分的1D和2D NMR光谱特征进行分析. 实验结果表明, ASP3是一种果胶多糖. GalpA和Rhap位于多糖分子的主链, 由1→4-D-GalpA相连形成的“光滑区”(半乳糖醛酸聚糖)是其主要组成部分; 由α-(1→4)-GalpA通过O4位与α-(1→2)-和α-(1→2,4)-Rhap的O2位交替连接所形成的重复单元[→4)-α-GalpA-(1→2)-α-Rhap-(1→]构成具有较高分支的“毛发区”(富含中性糖侧链的鼠李半乳糖醛酸聚糖). Galp和Araf是中性糖侧链的主要组成, 通过Rhap残基的O4位与主链相连. 非还原性末端T-β-Galp, β-(1→3)-, β-(1→3,6)-, β-(1→4)-, β-(1→4,6)-Galp聚合形成以β-(1→3,6)-Galp为分支点的β-(1→6)-半乳聚糖和以β-(1→4,6)-Galp为分支点的β-(1→4)-半乳聚糖. T-α-Araf, α-(1→5)-Araf和α-(1→3,5)-Araf聚合形成以α-(1→3,5)-Araf为分支点的α-(1→5)-阿拉伯聚糖. 此外, 由α-(1→5)-阿拉伯聚糖通过α-(1→3)连接与β-(1→6)-半乳聚糖末端聚合形成阿拉伯半乳聚糖.     

当归多糖的水解特征及其水解产物分析

对当归多糖ASP3的水解特征及其水解产物的组成和红外光谱特征进行了研究。分别采用0.05、0.2和0.5mol/L三氟乙酸(trifluoroacetic acid,TFA)和内切-α-(1→4)-聚半乳糖醛酸酶对ASP3进行部分酸水解和酶水解,并研究其水解特征;结合GC、FT-IR等方法对其水解产物的组成和红外光谱特征进行分析。实验结果表明,ASP3是一种果胶多糖,主要由光滑区(半乳糖醛酸聚糖)和毛发区(富含中性糖侧链的鼠李半乳糖醛酸聚糖)两部分组成:GalA和Rha位于多糖分子的主链,由于Rha含量较低,大部分GalA相连形成半乳糖醛酸聚糖光滑区;Gal、Ara、Man及Glc位于多糖分子的支链,其中Gal以较高的聚合度(半乳聚糖)与主链相连,Ara以还原性末端或低聚寡糖的形式与主链相连或与半乳聚糖末端相连形成阿拉伯半乳聚糖。     

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%.     

野菊花中性多糖CIP-C的分离纯化及结构解析

以野菊花为原材料, 经热水提取、乙醇沉淀、DEAE-Sepharose Fast Flow和Sephacryl S-200 凝胶柱层析分离纯化, 得到1个水溶性的中性多糖CIP-C. 采用GC-MS、部分酸水解及甲基化分析等对该多糖的结构进行了解析. 结果表明, 该多糖主要由D-Man, D-Glc和D-Gal组成, 并含有少量的D-Fuc, L-Ara和D-Xyl, 其主链由β(或α)-D-1,4-Man, β-D-1,6-Glc和β-D-1,4-Gal组成, 而阿拉伯糖通过α-L-T-Araf和α-L-1,5-Araf连接形成阿拉伯聚糖支链或与β-D-1,4-Galp的O3位相连形成阿拉伯半乳聚糖支链.     

基于高效阴离子色谱-脉冲安培法优化阿拉伯木聚精单精组成分析

以大粒车前子来源阿拉伯木聚糖为研究对象,采用完全酸水解结合高效阴离子色谱-脉冲安培法测定单糖组成,系统优化酸的种类和浓度、水解温度和时间、水解后样品放置时间等水解条件.结果表明,将车前子多糖置于2 mol/L H2 SO4、120℃常压油浴条件下水解2 h时,效果较好,但水解后稀释液放置时间不宜超过6 h.大粒车前子多糖主要由阿拉伯糖(8.89%)和木糖(41.52%)组成,同时检测出半乳糖醛酸(0.73%)、葡萄糖醛酸(3.44%)和微量的半乳糖、葡萄糖,结果重现性良好.利用上述最优条件水解黍子壳、燕麦麸皮和青稞来源阿拉伯木聚糖并分析单糖组成,均获得较好结果.本研究为分析各种来源阿拉伯木聚糖的单糖组成提供了参考.     

金钗石斛免疫活性多糖DNP-W1B的结构特征

从金钗石斛茎中获得了1个均一多糖组分DNP-W1B, 采用化学与光谱学结合的手段对其一级结构进行了解析. 结果表明, DNP-W1B分子量为7.7×10⁵, 比旋度²⁰_D=+81.3°(c0.3, H₂O), 由葡萄糖、 阿拉伯糖和半乳糖3种单糖组成, 摩尔比为6.2:3.1:0.9. DNP-W1B主链由1,4-和1,6-连接的葡萄糖残基组成, 在主链1,6-连接葡萄糖残基的4位形成分支, 支链由末端半乳糖残基和阿拉伯糖残基组成. 初步的免疫活性实验结果表明, DNP-W1B在体外能促进免疫细胞的增殖.     

巴戟天中一种多糖的分离与结构表征

以巴戟天的根为原料, 经热水浸提、Sevag法除蛋白、乙醇沉淀和DEAE-Sepharose CL-6B离子交换柱层析, 得到一种水溶性的巴戟天多糖(MOPI-3). 通过UV、IR、NMR、GC-MS、高碘酸氧化、Smith降解和甲基化等物理化学方法对MOPI-3的纯度、理化性质和组成结构进行表征. 结果表明, MOPI-3分子量为36061, 是一种由阿拉伯糖、半乳糖和葡萄糖组成的杂多糖, 以α-1,3-吡喃葡萄糖和α-1,4-吡喃半乳糖为主链, 平均每5个葡萄糖连接一个半乳糖, 每个重复单元具有一个支链, 支链由3个呋喃阿拉伯糖以α-1,3-键型组成, 连接在主链葡萄糖的6位碳上, MOPI-3含有乙酰基, 连接在主链半乳糖的2位碳原子上.     

黄芪葡聚多糖的化学结构

从植物黄芪(Astragalus mongholicus Bunges)根的碱性水提取液中得到一水溶性多糖黄芪葡聚糖. 它由单一葡萄糖残基构成, 分子量为5x10^4. 甲基化、过碘酸盐氧化、Smith降解和部分水解后, 揭示了它是以1,4-葡萄糖残基为主链, 并在6-O有分枝、重复单元为10个葡萄糖残基的葡聚糖(结构如3所示).     

黑小麦麦麸戊聚糖的部分酸水解特征与甲基化分析

研究了黑小麦麦麸戊聚糖(AEPH)的部分酸水解特征及其糖链的取代度和取代方式等结构信息. 分别采用0.02, 0.1和0.2 mol/L的三氟乙酸(Trifluoroacetic acid, TFA)对AEPH进行部分酸水解, 结合甲基化分析、 GC-MS和HPLC等方法对AEPH的糖链结构和相对分子质量分布进行了分析. 结果表明, 戊聚糖AEPH的糖残基主要由阿拉伯糖(Araf)和木糖(Xylp)组成. 其取代度(A/X), 即Araf与Xylp的比值为0.60, 并具有较高的相对分子质量(M_w=3.81×10⁵). AEPH的主链由Xylp残基通过1→4连接形成木聚糖. 主链Xylp在O2, O3或O2/O3位被Araf单取代或双取代. 非取代(u)、 单取代(m)和双取代(d)Xylp残基的组成比例为57.7∶22.0∶6.2. 非取代与取代Xylp的比值为2.1, 双取代与单取代Xylp比值(d/m)为0.3. Araf主要以非还原性末端T-Araf以及通过1→2和1→5连接形成低聚阿拉伯糖的形式与主链Xylp相连, 或与T-Xylp相连形成戊聚糖分子的支链.     

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.     

Acid-base properties of 2,3,4,5-tetrahydro-1H-naphtho[2,3-b]-1,4-diazepine-2,4,6, 11-tetraone

It is shown that 2,3,4,5-tetrahydro-1H-naphtho[2,3-b]-1,4-diazepine-2,4,6,11-tetraone, which has acid properties, undergoes methylation to give an N,N-di-methyl derivative, whereas it gives products of substitution of the hydrogen atoms of the methylene group in its reactions with bromine and salicylaldehyde. Treatment of 2,3,4,5-tetrahydro-1H-naphtho[2,3-b]-1,4-diazepine-2,4,6,11-tetrone with aqueous alkali or secondary aliphatic amines with heating is accompanied by opening of the diazepine ring to give hydrolysis (2-carboxyacetamido-3-hydroxy-1,4-naphthoquinones) or aminolysis (N-alkylaminomalonyl-2,3-diamino-1,4-naphthoquinones) products.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1132–1136, August, 1978.     

Structure Analysis of Pectin SB1-1 from the Root of Panax ginseng

A water-soluble pectin SB1-1 was isolated and purified from the root of Panax ginseng C. A. Mey. The HPLC analysis indicates that SB1-1 is homogenous. Its molecular weight was estimated via gel filtration to be 10000. The GC analysis indicated that it contains the monosaccharides of GalA, Gal, Ara and Rha. Their molar ratio is 2.10 : 1.00 : 0.12 : 0.13. Partial hydrolysis with acid, pectinase treatment, periodate oxidation, Smith degradation, methylation analyses, GC/MS analyses and NMR analyses were used for the structure analyses of SB1-1. The results reveal that SB1-1 has a lower branched structure. The main chain is composed of GalA and Gal; the inner part is a-1,4-linked-GalA; the border is 1,4-linked-Gal. Some of the 1,4-linked-GalA and 1.4-linked-Gal residues are substituted at O6. On an average, there is one branch for every ten hexose residues. The side chain is composed of 1,6-linked-Gal and 1,3,6-linked-Gal. The nonreduced end is composed of Rha, Ara and Gal. The main glycosidic link of SB1-1 has an a configuration.     

Synthesis, Cardiovascular Activity, and Electrochemical Oxidation of Nitriles of 5-Ethoxycarbonyl-2-methylthio-1,4-dihydropyridine-3-carboxylic Acid

Nitriles of 4-aryl-5-ethoxycarbonyl-2-methylthio-1,4-dihydropyridine-3-carboxylic acid have been obtained by the methylation of 1,4-dihydropyridine-2-thiolates; of 1,4-dihydropyridine-2(3H)-thiones in the presence of a stoichiometric amount of piperidine, and of a mixture of 1,4,5,6-tetrahydro- and 1,4-dihydropyridine-2-thiolates with methyl iodide. One-pot multicomponent synthesis has also been used in the condensation of ethyl 2-arylmethyleneacetoacetate, 2-cyanothioacetamide, piperidine, and methyl iodide; of ethyl acetoacetate, 3-aryl-2-cyanothioacrylamide, piperidine, and methyl iodide; and of ethyl acetoacetate, an aromatic aldehyde, 2-cyanothioacetamide, piperidine, and methyl iodide. The latter, a five-component method, takes place rapidly and under mild conditions, it is efficient (yields of 75-96%, economy of time, labour, and resources) and green (there is no need to synthesize lachrymators, such as 3-aryl-2-cyanothioacrylamides).The cardiovascular activity and the electrochemical oxidation of the synthesized 2-methylthio-1,4-dihydropyridines have been investigated. A comparative analysis has been carried out of the ability towards electrochemical oxidation as a function of the electronic properties of the substituent at position 4 of the heterocycle.     

Polysaccharides fromSpirulina platensis

A lipoglucan and a lipopolysaccharide have been isolated from an aqueous phenol extract of the cells ofSpirulina platensis. The carbohydrate moiety of the lipopolysaccharide consists of residues of rhamnose, glucose, 2-keto-3-deoxymanno-octanic acid, and glucosamine. A 2,3-di-O-methylpentose and a 2-O-methyl-6-deoxyhexose have been detected as minor components, and the presence of galactose, mannose, and xylose residues in trace amounts is possible. The lipid component of the biopolymers includes residues of glucosamine and of fatty acids: myristic, palmitic, and stearic. The carbohydrate chain of the lipoglucan is constructed of 1,4-bound glucose residues. The side chains are attached to the main chain by 1,6-glycosidic bonds. The polysaccharide component of the liposaccharide is constructed mainly of rhamnose residues linked by 1,3- and 1,2-bonds and of glucose residues linked by 1,4-bonds.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 135–139, March–April, 1983.     

Polysaccharides from the inflorescences ofMatricaria matricarioides

Fractionation of the polysacchride complex of the inflorescences of pineapple weed has given a galacturonan and a pectic acid. The structures of the galacturonan and pectic acid have been studied by the methods of enzymatic hydrolysis, periodate oxidation, and exhaustive methylation. It has been established that the galacturonan is a linear polysaccharide consisting of D-galacturonic acid residues in the pyranose form with -14-bonds. The main polysaccharide chain of the pectic acid consists of D-galacturonic acid residues in the pyranose form, D-galactose, L-arbinose, and D-xylose residues are covalently bound to carbon atoms 2 or 3 of the main chain of the polysaccharide.I. P. Pavlov Medical Institute, Ryazan'. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 481–486, July–August, 1985.     

Synthesis and Rearrangement of Mono and Bis-(p-Fluorophenyl)Hydrazones of Dehydro-L-Ascorbic Acid

Abstract

The mono- and bis-(p-fluorophenyl)hydrazones of dehydro-L-ascorbic acid were prepared. Oxidation of the bis(hydrazone) afforded 3,6-anhydro-3-C-(p-fluorophenylazo) L-xylo-2-hexul osono-1,4-1 actone-2-(p-fluorophenyl)hydrazone. Rearrangement of the bis(hydrazone) gave T-(p-fluorophenyl)-3-(L-threo-glycerol-1-yl)-pyrazoli n-4,5-di one-4-(p-fluorophenyl)hydrazone, whose periodate oxidation gave 3-formyl-1-(p-fluorophenyl pyrazol in-4.5-dione-3-4-(p-fluorophenyl)hydrazone that upon reduction gave 1-(p-fluorophenyl)-3-hydroxymethyl pyrazol in-4,5-dione-4-(p-fluorophenyl)hydrazone. The compounds were characterized as their acetates and benzoates.