Studies on Sulfation of Lycium barbarum Polysaccharides

Polysaccharides can anti-virus, such as human immunodeficiency virus (HIV-1),[1] herpes simplex virus (HSV-1,HSV-2) and cytomegalovirus. Some of them are sulfates, e.g. dextran sulfate, heparin, sulfonation of chitosan and sulfated derivatives of Lentinan. Our results showed that sulfated derivatives of Lycium barbarum polysaccharides (LBP)have anti-HIV activity. Because the anti-HIV activity of LBP was deeply dependent on the molecular weight, the sulfation pattern and glycosidic branches besides degree of sulfation (DS), so we emphasized our work on the factors of DS.     

A Modular Approach to a Library of Semi‐Synthetic Fucosylated Chondroitin Sulfate Polysaccharides with Different Sulfation and Fucosylation Patterns

Fucosylated chondroitin sulfate (fCS)—a glycosaminoglycan (GAG) found in sea cucumbers—has recently attracted much attention owing to its biological properties. In particular, a low molecular mass fCS polysaccharide has very recently been suggested as a strong candidate for the development of an antithrombotic drug that would be safer and more effective than heparin. To avoid the use of animal sourced drugs, here we present the chemical transformation of a microbial sourced unsulfated chondroitin polysaccharide into a small library of fucosylated (and sulfated) derivatives thereof. To this aim, a modular approach based on the different combination of only five reactions was employed, with an almost unprecedented polysaccharide branching by O‐glycosylation as the key step. The library was differentiated for sulfation patterns and/or positions of the fucose branches, as confirmed by detailed 2D NMR spectroscopic analysis. These semi‐synthetic polysaccharides will allow a wider and more accurate structure–activity relationship study with respect to those reported in literature to date.     

Direct Identification of Tyrosine Sulfation by using Ultraviolet Photodissociation Mass Spectrometry

Sulfation is a common post-translational modification of tyrosine residues in eukaryotes; however, detection using traditional liquid chromatography-mass spectrometry (LC-MS) methods is challenging based on poor ionization efficiency in the positive ion mode and facile neutral loss upon collisional activation. In the present study, 193 nm ultraviolet photodissociation (UVPD) is applied to sulfopeptide anions to generate diagnostic sequence ions, which do not undergo appreciable neutral loss of sulfate even using higher energy photoirradiation parameters. At the same time, neutral loss of SO₃ is observed from the precursor and charge-reduced precursor ions, a spectral feature that is useful for differentiating tyrosine sulfation from the nominally isobaric tyrosine phosphorylation. LC-MS detection limits for UVPD analysis in the negative mode were determined to be around 100 fmol for three sulfated peptides, caerulein, cionin, and leu-enkephalin. The LC-UVPD-MS method was applied for analysis of bovine fibrinogen, and its key sulfated peptide was confidently identified.

Crystal Design of Barium Sulfate using Double-Hydrophilic Block Copolymers

Peach, peanut, fiber, and flower (see picture) crystal morphologies are achieved from the precipitation of simple minerals in the presence of specifically adsorbing polymers. These crystal design effects are illustrated using BaSO(4) and double-hydrophilic block copolymers, the latter featuring carboxylate, sulfonate, phosphonate, and aspartic acid groups.     

Sulfation: a new biocombinatorial tool

Considerable progress has been achieved in derivatization of glycopeptide antibiotics by using genetic engineering and in vitro enzymatic approaches. In this issue of Chemistry & Biology, the identification and application of a glycopeptide-specific sulfotransferase by Lamb et al. expands the tool box of biocombinatorial synthesis.     

Selective Sulfation of Chitin Derivatives for Biomedical Functions

The highest antithrombogenic activity was achieved by the N- and O-sulfation of partially N-deacetylated (70%) 6-O-carboxymethyl (0.60)-chitin (SCM-DAC-70) among various modified chitin derivatives. But a O-sulfated 6-O-carobxymethyl-chitin (SCM-chitin) was a quite in- ert heparinoid for the inhibition of blood clotting. It was also suggested that the distribution of N-sulfate and N-acetyl groups on the C-2 position of glucosamine residue might be essential to the selective adsorption of SCM-DAC-70 to antithrombin-III (AT-III) to inhibit thrombin activity. Kinetic evaluations demonstrated the noncompetitive inhibition of thrombin activity by SCM-DAC-70 and competitive inhibition of throm- bin by SCM-DAC-70-AT-III complex. We were unable to find such a specific inhibition by the SCM-DAC-70 complex with blood clotting factors other than AT-III. SCM-chitin was found to inhibit the metasta- sis of cancer cells at about 80–85% without any side effect different from those of heparin. It was suggested that the inhibition of metastasis of B16-BL6 melanoma cells was achieved by bifunctional inhibitions for heparanase and type IV collagenase without growth inhibition of cancer cells.     

Sulfation of polysaccharides with sodium pyrosulfate in dimethyl sulfoxide

Sulfo esters of cellulose, dextran, starch, and amylopectin with a degree of substitution equal to 0.1–1.1 were prepared in the system constituted by sodium pyrosulfate and dimethyl sulfoxide. The intrinsic viscosity of aqueous solutions of sulfo polysaccharides was determined, and their anticoagulant activity was evaluated.     

Sulfation of dextran with chlorosulfonic acid in organic solvents

Solutions of chlorosulfonic acid in dichloroethane and formamide are suggested for incorporation of sulfo groups into macromolecules of polysaccharides. The influence of temperature, reaction duration, and reactant ratio on the yield of sulfated dextran and also the influence of the reaction conditions on hydrolytic stability of the polymer were studied.     

间接分光光度法测定多糖硫酸酯中硫酸根

提出了一种间接分光光度法测定多糖硫酸酯中硫酸根含量的方法。取一定量的经水解后的试样溶液,加入已知且过量的氯化钡标准溶液使试样溶液中的硫酸根以BaSO4形式沉淀析出,放置5 min后,加入已知且过量的标准铬酸钾溶液使过量钡离子以BaCrO4形式沉淀析出,经离心使沉淀与溶液分离。定量移取上层清液,于pH 3.4的HOAc-NaOAc缓冲溶液中加入邻联甲苯胺,使与过量的CrO24-反应生成蓝绿色产物,于624 nm波长处测得其吸光度。结果表明硫酸根质量在50~250μg之间服从比耳定律。对方法的精密度和回收率作了试验,测得相对标准偏差(n=6)为1.55%,平均回收率为99.25%。     

Sulfation of carboxy starch with sodium pyrosulfate in dimethyl sulfoxide

Chemical modification of potato carboxy starch in the sodium pyrosulfate— dimethyl sulfoxide system was studied with the aim of preparing water-soluble highly substituted sulfo esters. The dependence of the degree of sulfo group substitution on the reaction conditions was studied in detail. The optimal conditions ensuring formation of water-soluble sulfo esters of carboxy starch with the maximal sulfur content were determined. The carboxy starch sulfo ester samples synthesized were characterized by elemental analysis, IR and ¹³C NMR spectroscopy, and high-performance exclusion chromatography.     

Sulfate anion templation of a neutral pseudorotaxane assembly using an indolocarbazole threading component

The first example of anion templated pseudorotaxane formation between two neutral components in solution and in surface assembled monolayers is described.     

Retention Behaviors of Uronic Acid-containing Polysaccharides and Neutral Polysaccharides in HPGPC

The determination of molecular weights (Mw) of polysaccharides has served as an important process since the physical properties of the polysaccharides are closely related to their Mw and/or molecular weights distribution (MWD). For Mw and MWD determinations, high performance gel permeation chromatography (HPGPC) has gained wide acceptance as a preferred method due to its high sensitivity, speed and reproducibility. In chromatography, it is well known that the molecular weights are determ…     

Polysaccharides of Achillea asiatica

Tomsk Medical Institute. Institute of the Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 136–137, January–February, 1988.     

Multistage Tandem Mass Spectrometry of Chondroitin Sulfate and Dermatan Sulfate

Chondroitin/dermatan sulfate (CS/DS) is a glycosaminoglycan (GAG) found in abundance in extracellular matrices. In connective tissue, CS/DS proteoglycans play structural roles in maintaining viscoelasticity through the large number of immobilized sulfate groups on CS/DS chains. CS/DS chains also bind protein families including growth factors and growth factor receptors. Through such interactions, CS/DS chains play important roles in neurobiochemical processes, connective tissue homeostasis, coagulation, and cell growth regulation. Expression of DS has been observed to increase in cancerous tissue relative to controls. In earlier studies, MS(2) was used to compare the types of CS/DS isomers present in biological samples. The results demonstrated that product ion abundances reflect the types of CS/DS repeats present and can be used quantitatively. It was not clear, however, to which of the CS/DS repeats the product ions abundances were sensitive. The present work explores the utility of MS(3) for structural characterization of CS/DS oligosaccharides. The data show that MS(3) product ion abundances correlate with the presence of DS-like repeats in specific positions on the oligosaccharide chains.