纯品枸杞多糖对小鼠抗疲劳的效果

将纯品枸杞多糖分为５,１０,２０,５０,１００ ｍ ｇ·ｋｇ－ １ ·ｄ－ １等５ 个不同剂量的实验组,灌喂小鼠,观察其对小鼠抗疲劳的效果纯品枸杞多糖能显著地增加小鼠肌糖原、肝糖原储备量;提高运动前及游泳后 ９０ ｍ ｉｎ 及 １５０ｍ ｉｎ Ｌ Ｄ Ｈ 总活力;降低小鼠剧烈运动后血尿素氮增量,加快运动后血尿素氮的恢复速率;以１０ ｍ ｇ·ｋｇ－ １ ·ｄ－ １ 剂量组效果最佳 提示纯品枸杞多糖在提高机体对运动员负荷的适应能力,抵抗疲劳产生和加速疲劳的消除具有十分明显的作用     

羟乙基化牛膝多糖的合成及其活性研究

以环氧乙烷为羟乙基化试剂，在碱性水溶液中，对牛膝多糖进行羟乙基化，经 过丙酮沉淀、膜分离、Sephadex G-25柱层析等分离方法得到羟乙基化牛膝多糖纯 品，检测其理化性质，并通过甲基化、GC-MS分析，初步确证糖链中羟乙基主要取 代在葡萄糖6位和困糖的1位上。药理实验表明，羟乙基化牛膝多糖对荷Lewis肺癌 小鼠NK活性具有一定促进作用。     

海洋硫酸多糖911的荧光标记研究

硫酸多糖（911）的性末端的半缩醛基,通过还原胺化反应与酪胺（Tyr)的氨基共价偶联,911－Tyr中酪胺引入的仲氨基通过与异硫氰酸酯荧光素（FITC）进行亲核反应,实现对911还原末端的选择性荧光标记。用UV－Vis吸收光谱,^1H NMR和HPSEC对偶联与标记结果进行确证,从^1H NMR谱推测911与酪胺的偶联率及FITC为911－Tyr标记率分别为60％和80％。由于采用的是911末端选择性标记,对911的抗凝活性无明显影响,也无明显细胞的毒性。以荧光标记的911作为探针,对淋巴细胞有较强的选择性标记染色。该法适用于具有还原末端的多糖及寡糖的荧光标记。     

Interaction of albumin with polysaccharides containing ionic groups

It is very important to clarify the mechanisms of the interaction between components of organisms. In this report, the interaction between bovine serum albumin (BSA) and ionic polysaccharides were discussed. The fluorescence spectrum of tryptophan (Trp) in BSA changed as its conformation changed. On adding polysaccharide containing sulfonic acid residues (sulfonic‐type) at pH 7.4, a remarkable blue shift of the emission maximum (λ_em) of Trp was observed. This blue shift was decreased by adding NaCl. In contrast, polysaccharide containing carboxylic acid residues (carboxy‐type) scarcely changed Trp fluorescence at the same pH. At a pH lower than the isoelectric point (PI = 4.7–4.9) of BSA, a remarkable blue shift was observed not only by adding sulfonic‐type polysaccharide but also by adding carboxy‐type polysaccharide. Moreover, using the energy transfer method, in the pH region higher than the PI of BSA, carboxylic‐type polysaccharides may interact relatively weakly with the binding site II of BSA, but sulfonic‐type ones can selectively interact with binding site I weakly and with binding site II strongly. And in the pH region lower than the PI of BSA, carboxylic‐type polysaccharides interact with binding site II strongly. On the other hand, sulfonic‐type polysaccharides are bound to both binding site I and binding site II very strongly. Copyright © 1999 John Wiley & Sons, Ltd.     

海藻硫酸多糖抑制草酸钙结石形成的化学模拟

用体外模拟方法研究了从海藻异枝麒麟菜中提取的硫酸多糖(ESPS)对尿结石患者尿液中草酸钙晶体生长的影响. ESPS不但诱导与尿路细胞膜粘附力较弱的二水草酸钙晶体形成, 而且抑制一水草酸钙的生长和聚集, 归因于一水草酸钙的富钙(101)晶面与聚阴离子ESPS之间的静电相互作用. 上述结果表明, ESPS是一种抑制草酸钙结石的潜在绿色药物.     

甘草多糖螺旋结构的原子力显微镜研究

用原子力显微镜(AFM)对甘草多糖的微观结构进行观察, 实验结果表明, 甘草多糖主要由葡萄糖、阿拉伯糖和半乳糖组成. 甘草多糖分子的稀溶液铺展在Ni^2＋处理的云母片上, 经干燥, 乙醇固定后, 获得稳定、重复的图像. 甘草多糖分子具有高度分枝的结构, 并且糖链间形成环状、柱状或近似于螺旋状的结构. 甘草多糖链呈多股紧密的螺旋结构, 这种现象可能与该多糖中分子间的Van der Waals相互作用以及糖链间氢键缔合有关.     

硫酸化高山红景天多糖(RSASL)的制备及鉴定

从高山红景天中分离出一种酸性杂多糖（ＲＳＡ）．该多糖由阿拉伯糖（Ａｒａ）、鼠李糖（Ｒｈａ）、半乳糖（Ｇａｌ）、木糖（Ｘｙｌ）、葡萄糖（Ｇｌｃ） 与半乳糖醛酸（ＧａｌＡ）组成,其单糖摩尔比为１．００∶３ ．２３∶０ ．２６∶０ ．３４∶０ ．８４∶１０．２４．用氯磺酸－吡啶法制备硫酸化高山红景天多糖（ＲＳＡＳＬ）．用离子色谱法测定ＲＳＡＳＬ 中Ｓ的质量分数为１１．０１％ ,其硫酸基取代度为０．８５．用红外光谱,紫外光谱,Ｓｅｐｈａｒｏｓｅ ＣＬ－４Ｂ柱层析,激光解吸电离飞行时间质谱等方法鉴定,ＲＳＡＳＬ均显示了多糖硫酸酯的特征     

Structure Determination of Cellulose Esters via Subsequent Functionalization and NMR Spectroscopy

New paths for the fast and reliable analysis of cellulose esters (CE) via subsequent functionalization and ¹H NMR spectroscopy were studied. Perpropionylation of the CE is an inexpensive and efficient method. For cellulose diacetates used as representative ester well resolved ¹H NMR spectra were obtained, which can be used for the calculation of the over all degree of substitution (DS) and the partial DS values at position 2, 3, and 6. No transesterification occurs during the subsequent acylation and a standard deviation of S² = 1.32 x 10⁻⁴ was found for a series of experiments. In case of more complex ester structures especially with extended aliphatic moieties per-4-nitrobenzoylation need to be applied prior to NMR measurements. The spectra obtained can be completely assigned and applied for the calculation of DS values.     

对比生物体系以及合成体系中单核铜氧物种对碳氢键和氧氢键活化的理论研究展望

由于具有较好的催化性能,含过渡金属的酶一直备受研究者的关注.其中,铜作为生物体中含量仅次于铁和锌的过渡金属,在新陈代谢过程中发挥着重要作用.铜酶广泛存在于自然界中,该类生物大分子涉及电子转移、氧化还原、氧气的运输与活化等生物化学过程.多种铜酶在氧气活化方面表现出引人注目的 性质,例如:颗粒状甲烷单加氧酶(pMMO)、多...     

SYNTHESIS AND CATIONIC RING-OPENING POLYMERIZATION OF 1, 4-ANHYDRO-2, 3-DI-O-(P-AZIDOBENZYL)-α-D-RIBOPYRANOSE

New highly stereoregular 2, 3 -di- O-(p-azidobenzyl )-(1 →5 ) - α-D -ribofuranan was synthesized byselective ring-opening polymerization of 1, 4-anhydro-2, 3 - di-O -(p-azidobenzyl )-α-D -ribopyranose(ADABR) using phosphorus pentafluoride or tin tetrachloride as catalyst at low temperature indichloromethane. The monomer was obtained by the reaction of p - bromomethyl -phenyleneazide with 1, 4 -anhydro-α-D-ribose in DMF. The structure of poly(ADANR) was identified by specific rotation and ~(13)C-NMR spectroscopy. Acid chloride-AgCl_4 complex catalyst such as CH_2=C(CH_3)C~+OClO_4~- used in thepolymerization resulted in polymers with mixed structures, i.e. (1→5)-α-D-ribofuranosidic and (1→4)-β-D-ribopyranosidic units. However, with C_6H_5C~+OClO_4~- as catalyst, pure (1→5)-α-D-ribofuranan was obtained.The effects of catalyst, polymerization temperature and time on polymer stereoregularity were examined, andthe mechanism of the ring-opening polymerization was discussed.