滇桂艾纳香水溶性多糖BRP-B的分离纯化及止血活性

用蒸馏水溶解滇桂艾纳香浸膏,从中提取多糖,通过膜分离、三氯乙酸法脱蛋白、二乙氨基乙基(DEAE)脱色、SephadexG10、SephadexG50凝胶柱色谱纯化,获得滇桂艾纳香水溶性多糖(BRP-B)。 由凝胶渗透色谱（HPGPC）确定BRP-B为相对分子质量分布均一的多糖,其数均分子量和质均分子量分别为2654和2716 Da。 以血浆复钙时间（PRT）为指标,研究BRP-B的凝血活性,结果显示BRP-B质量浓度为6.25×10-2 g/L时,凝血时间为248.52 s,凝血时间抑制率达22.42%。 小白鼠离体子宫实验结果显示,BRP-B质量浓度为1.67×10-2、1.97×10-2及2.85×10-2 g/L时能明显增加子宫平滑肌的收缩频率。     

新的滇桂艾纳香寡糖BROS结构分析

以滇桂艾纳香枝叶为原料,经陶瓷膜、有机膜分离,醇沉、Sevag法除蛋白,DEAE-纤维素柱层析和SephadexG- 10,SephadexG-50凝胶柱色谱纯化得到的BROS;经HPGPC检测分析表明,BROS为均一寡糖,MALDI-TOF-MS测定分子量为1314.用IR,HPLC,甲基化分析,GC-MS,NMR (1H NMR,13C NMR,1H)HCOSY,HMQC和HMBC)等方法对BROS结构进行表征,结果表明,该寡糖由1个葡萄糖(α-D-Glcp)和7个果糖(β-D-Fru组成,残基间以→2)Fruf-(1→链接,分子末端链接为a-Glcp-(1→,→2)-β-D-Fruf推出BROS的结构式为:β-D-Fruf1-(2→1)-β-D-Fruf2-(2→1)-β-D-Fruf3-(2→ 1)-β-D-Fruf4-(2→1)-β -D-Fruf5-(2→1)-β-D-Fruf6-(2→ 1)-β-D-Fruf7-(2→ 1)-a-D-Glcp.     

香云多糖的分子表征和稀溶液性质研究

The polysaccharide of lentinus edodes and polytictus versicolor has been fractionated by repeated precipitation method.All fractions and the unfractionated samples have been characterized by rapid dynamic membrane osmometry. For its aqueous solution, the second virial coefficient A₂ decreases as the molecular weight increases. The relationship is A₂= 2 slope (MnRT)-1/2.Determination of the distribution curve by means of fractional precipitation. Separation of a polysaccharide into six fractiona by a fractional precipitation carried out. The distribu-tion-curve of integral and differential is obtained. After according to the modified Elias'cloud-point titration method and using an Abbe's refractometer to define the clou-point,^[6-]8it was found that water/acetone (89:11 by vo-lume) is a θ solvent for the polymer at 25±0.05 C. For θ conditions,the intrinsic viscosities were determined by capillary viscometry. Thus a monodispersed [n]-M relationship has been obtained: [n]_θ=2.59×10^-2M^0.509 From the result above the unperturbed dimensi on(r²_θ)^1/2 was found to be 4.7×10^-9M^1/2.     

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.     

白术多糖的分离纯化与结构表征

采用UV, IR, NMR, GC-MS, 高碘酸氧化和Smith降解等物理化学方法对从白术根茎提取的白术多糖的纯度、理化性质和结构进行了表征. 以中药白术的根茎为原料, 通过热水(80 ℃)浸提和乙醇醇沉得到粗多糖, 再经DEAE-52阴离子交换柱层析分离和Sephadex G-200凝胶柱层析纯化, 得到一种水溶性的白术多糖(WAM). 经高效液相色谱(HPLC)分析, 多糖WAM是分子量约为3263的均一多糖. GC分析表明, WAM是由葡萄糖和半乳糖以摩尔比3.01:1构成的杂多糖. 甲基化分析、高碘酸氧化、Smith降解、部分酸水解、NMR和IR等分析结果表明, WAM具有多分支结构, 主链由β-D-1→3和β-D-1→3,6吡喃葡萄糖构成, 每个重复单元具有一个支链, 支链由β-D-半乳糖构成, 连接在主链葡萄糖的6位碳原子上.     

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.     

一种乳酸菌胞外多糖糖链结构解析

以分离纯化得到的一种嗜热链球菌分泌的胞外多糖EPS03-1gm为研究对象, 采用气相色谱、分光光度及核磁共振技术对该多糖重复单位结构进行了解析. 结果表明, EPS03-1gm的单糖组成是葡萄糖和半乳糖, 不含糖醛酸和蛋白成分, 其重复单位中有4个糖基单元且都是6C糖. DEPT谱说明每个重复单位中有4个CH2, 用二维核磁共振谱和HMQC及HMBC谱分别对4个糖单元中的H和C进行了归属. 确定该多糖重复单位的糖链结构为: →3)-α-D-Galp-(1→3)-β-D-Galf-(1→3)-β-D-Glcp-(1→6)-β-D-Glcp-(1→.     

日香桂根的化学成分研究

利用硅胶和凝胶柱层析等方法对日香桂的化学成分进行了研究。从日香桂根的95%乙醇提取物中分离出7个单体化合物,分别为β-胡萝卜苷(1),连翘脂素(2),大黄酚(3),大黄素甲醚(4),β-谷甾醇(5),β-谷甾酮(6)和2-(4-羟基苯基)乙酸乙酯(7),其结构经1H NMR和13C NMR确证。2～4,6和7为首次从日香桂中发现;2为首次从该属中发现;3和4为首次从该科中发现。     

茯苓菌核多糖的分离和结构分析

分别用０．９％ＮａＣｌ不溶液，热水，０．５ｍｏｌ／Ｌ ＮａＯＨ水溶液和８８％甲酸从新鲜茯苓菌核体中提取出５种多糖：ＰＣ１，ＰＣ２，ＰＣ２－Ａ，ＰＣ３和ＰＣ４．用ＩＲ，ＨＰＬＣ，ＧＣ，＾１ＨＮＭＲ和＾１３Ｃ ＮＭＲ等方法分析了它们的组成和结构。结果表明，ＰＣ１，ＰＣ２和ＰＣ２－Ａ由Ｄ－葡萄糖，Ｄ－木糖，Ｄ－甘露糖和Ｄ－半乳糖组成，ＰＣ１和ＰＣ２－Ａ含葡萄糖醛酸，其葡萄糖含量随提取过程的进行逐渐增加。     

茶多糖的纯化及结构分析

从茶多酚生产的下脚料中,通过有机溶剂洗涤和凝胶色谱分离,得到一种水溶性多糖.经高效液相色谱分析,为单一茶多糖,其相对分子量为(10～10.5)×105;气相色谱分析表明,糖基由葡萄糖、半乳糖、阿拉伯糖、甘露糖和鼠李糖组成,其摩尔比为6.97:5.34:8.11:2.76:1.14;比色法测其总糖含量、蛋白含量、糖醛酸含量分别为90%、8.52%、27.65%.红外光谱和核磁共振分析表明,该多糖足由单糖通过β-糖苷键连接的,多糖链上络有糖醛酸、氨基或蛋白基团,同时含有α和β异头碳;x-衍射分析显示,随多糖纯度的提高,茶多糖更易结晶,且有不同的品体聚合物出现;DSC的分析表明,随茶多糖纯度的提高,热焓增加,峰温向高温漂移.     

Isolation and structural characterization of a low-molecular-weight pectic polysaccharide SHPPB-1 isolated from sunflower heads

A novel low-molecular-weight pectic polysaccharide was isolated from sunflower heads that are a useless side product produced from sunflower oil processing. The low-molecular-weight pectic polysaccharide was purified by using an optimized four-step procedure and named as SHPPB-1. The molecular weight of SHPPB-1 is about 1.69× 10⁴ Da. Structure characterizations of SHPPB-1 by monosaccharide composition, methylation analysis, and Fourier transform infrared (FT-IR) spectroscopy showed that SHPPB-1 is consisted of 1,4-linked α-D-GalpA and 1,4-linked 2-OAc-5-COOMe-α-D-GalpA with rare α/β-D-Rhap, α/β-D-Manp, and α/β-D-GalpA. This was combined with NMR spectroscopic analysis to propose a structure of SHPPB-1 as: →4)-[α/β-D-monosaccharide-(1→3)]-α-D-GalpA-(1→4)-2-OAc-5-COOMe-α-D-GalpA-(1→ .     

Structure of an Extracellular Polysaccharide from a Strain of Lactic Acid Bacteria

A new extracellular polysaccharide (EPS-I) isolated and purified from Z222, a strain of Lactic acid bacteria has been investigated. Sugar composition analysis, methylation analysis and ^1H NMR and ^13C NMR spectroscopy reveal that the EPS-I is composed of a pentasaccharide repeating unit. The sequence of sugar residue was determined by using two-dlmensional NMR spectroscopy, including heteronudear multiple-bond correlation(HMBC) and nuclear overhauser effect spectroscopy (NOESY).     

鬼毛针中碱溶多糖的结构和生物活性

鬼毛针多糖;抗肿瘤活性;鬼毛针中碱溶多糖的结构和生物活性     

铁皮石斛原球茎多糖DCPP3c-1的分离纯化及结构初步分析

铁皮石斛原球茎粗多糖(DCPP)经阴离子交换纤维素柱(DEAE-2)和凝胶柱(Sephadex G-200)依次层析,分离纯化得灰色多糖DCPP3c-1.其纯度经比旋光度法、柱层析、紫外扫描检测,组分和结构经薄层层析、高效液相色谱、红外光谱及高碘酸钠氧化等试验分析.结果显示DCPP3c-1为均一组分,相对分子质量为72.4 ku.由甘露糖、鼠李糖、半乳糖醛酸、葡萄糖、半乳糖和阿拉伯糖组成,其分子物质的量之比为1.120 4:1:1.046:23.354:3.828:1.046.分子中1→6残基占14%,1→2或1→4残基占40.7%,1→3键占45.3%.红外光谱显示其具有多糖特征吸收峰,并存在吡喃糖苷键.DCPP3c-1是首次从液体悬浮培养的原球茎中分离得到的新型酸性杂多糖组分.     

ACD/Structure Elucidator: 20 Years in the History of Development

The first methods associated with the Computer-Assisted Structure Elucidation (CASE) of small molecules were published over fifty years ago when spectroscopy and computer science were both in their infancy. The incredible leaps in both areas of technology could not have been envisaged at that time, but both have enabled CASE expert systems to achieve performance levels that in their present state can outperform many scientists in terms of speed to solution. The computer-assisted analysis of enormous matrices of data exemplified 1D and 2D high-resolution NMR spectroscopy datasets can easily solve what just a few years ago would have been deemed to be complex structures. While not a panacea, the application of such tools can provide support to even the most skilled spectroscopist. By this point the structures of a great number of molecular skeletons, including hundreds of complex natural products, have been elucidated using such programs. At this juncture, the expert system ACD/Structure Elucidator is likely the most advanced CASE system available and, being a commercial software product, is installed and used in many organizations. This article will provide an overview of the research and development required to pursue the lofty goals set almost two decades ago to facilitate highly automated approaches to solving complex structures from analytical spectroscopy data, using NMR as the primary data-type.     

Structural Characterization of a Polysaccharide from Gastrodia elata and Its Bioactivity on Gut Microbiota

A novel homogeneous polysaccharide named GEP-1 was isolated and purified from Gastrodia elata (G. elata) by hot-water extraction, ethanol precipitation, and membrane separator. GEP-1, which has a molecular weight of 20.1 kDa, contains a polysaccharide framework comprised of only glucose. Methylation and NMR analysis showed that GEP-1 contained 1,3,6-linked-α-Glcp, 1,4-linked-α-Glcp, 1,4-linked-β-Glcp and 1,4,6-linked-α-Glcp. Interestingly, GEP-1 contained citric acid and repeating p-hydroxybenzyl alcohol as one branch. Furthermore, a bioactivity test showed that GEP-1 could significantly promote the growth of Akkermansia muciniphila (A. muciniphila) and Lacticaseibacillus paracasei (L. paracasei) strains. These results implied that GEP-1 might be useful for human by modulating gut microbiota.     

Structural Features of a Polysaccharide from Centella asiatica

Centella asiatica has been used as remedy for sodation, stabilization and against lepra, anabrosis1 in the oriental countries. The low-molecular-weight constituents in Centella asiatica have been investigated1. However, no polysaccharides have been reported. 1BI was the first polysaccharide isolated from C. asiatica, which had immunostimulating activity in vitro. In present study, we report the structural features of 1BI. Experimental Extraction, isolation and purification Dried C.…