Advances In Carbohydrate Chemistry Research Articles

Serum N-Glycome Diversity in Teleost and Chondrostrean Fishes.

Recent advances in carbohydrate chemistry, chemical biology, and mass spectrometric techniques have opened the door to rapid progress in uncovering the function and diversity of glycan structures associated with human health and disease. These strategies can be equally well applied to advance non-human health care research. To date, the glycomes of only a handful of non-human, non-domesticated vertebrates have been analyzed in depth due to the logistic complications associated with obtaining or handling wild-caught or farm-raised specimens. In contrast, the last 2 decades have seen advances in proteomics, glycoproteomics, and glycomics that have significantly advanced efforts to identify human serum/plasma biomarkers for various diseases. In this study, we investigated N-glycan structural diversity in serum harvested from five cultured fish species. This biofluid is a useful starting point for glycomic analysis because it is rich in glycoproteins, can be acquired in a sustainable fashion, and its contents reflect dynamic physiologic changes in the organism. Sera acquired from two chondrostrean fish species, the Atlantic sturgeon and shortnose sturgeon, and three teleost fish species, the Atlantic salmon, Arctic char, and channel catfish, were delipidated by organic extraction and the resulting protein-rich preparations sequentially treated with trypsin and PNGaseF to generate released N-glycans for structural analysis. Released N-glycans were analyzed as their native or permethylated forms by nanospray ionization mass spectrometry in negative or positive mode. While the basic biosynthetic pathway that initiates the production of glycoprotein glycan core structures is well-conserved across the teleost fish species examined in this study, species-specific structural differences were detected across the five organisms in terms of their monosaccharide composition, sialylation pattern, fucosylation, and degree of O-acetylation. Our methods and results provide new contributions to a growing library of datasets describing fish N-glycomes that can eventually establish species-normative baselines for assessing N-glycosylation dynamics associated with pathogen invasion, environmental stress, and fish immunologic responses.

The Biogeochemistry of Marine Polysaccharides: Sources, Inventories, and Bacterial Drivers of the Carbohydrate Cycle.

Polysaccharides are major components of macroalgal and phytoplankton biomass and constitute a large fraction of the organic matter produced and degraded in the ocean. Until recently, however, our knowledge of marine polysaccharides was limited due to their great structural complexity, the correspondingly complicated enzymatic machinery used by microbial communities to degrade them, and a lack of readily applied means to isolate andcharacterize polysaccharides in detail. Advances in carbohydrate chemistry, bioinformatics, molecular ecology, and microbiology have led to new insights into the structures of polysaccharides, the means by which they are degraded by bacteria, and the ecology of polysaccharide production and decomposition. Here, we survey current knowledge, discuss recent advances, and present a new conceptual model linking polysaccharide structural complexity and abundance to microbially driven mechanisms of polysaccharide processing. We conclude by highlighting specific future research foci that will shed light on this central but poorly characterized component of the marine carbon cycle.

Automated Chemical Oligosaccharide Synthesis: Novel Approach to Traditional Challenges.

Advances in carbohydrate chemistry have certainly made common oligosaccharides much more accessible. However, many current methods still rely heavily upon specialized knowledge of carbohydrate chemistry. The application of automated technologies to chemical and life science applications such as genomics and proteomics represents a vibrant field. These automated technologies also present opportunities for their application to organic synthesis, including that of the synthesis of oligosaccharides. However, application of automated methods to the synthesis of carbohydrates is an underdeveloped area as compared to other classes of biomolecules. The overarching goal of this review article is to present the advances that have been made at the interface of carbohydrate chemistry and automated technology.

The logic of automated glycan assembly.

Carbohydrates are the most abundant biopolymers on earth and part of every living creature. Glycans are essential as materials for nutrition and for information transfer in biological processes. To date, in few cases a detailed correlation between glycan structure and glycan function has been established. A molecular understanding of glycan function will require pure glycans for biological, immunological, and structural studies. Given the immense structural complexity of glycans found in living organisms and the lack of amplification methods or expression systems, chemical synthesis is the only means to access usable quantities of pure glycan molecules. While the solid-phase synthesis of DNA and peptides has become routine for decades, access to glycans has been technically difficult, time-consuming and confined to a few expert laboratories. In this Account, the development of a comprehensive approach to the automated synthesis of all classes of mammalian glycans, including glycosaminoglycans and glycosylphosphatidyl inositol (GPI) anchors, as well as bacterial and plant carbohydrates is described. A conceptual advance concerning the logic of glycan assembly was required in order to enable automated execution of the synthetic process. Based on the central glycosidic bond forming reaction, a general concept for the protecting groups and leaving groups has been developed. Building blocks that can be procured on large scale, are stable for prolonged periods of time, but upon activation result in high yields and selectivities were identified. A coupling-capping and deprotection cycle was invented that can be executed by an automated synthesis instrument. Straightforward postsynthetic protocols for cleavage from the solid support as well as purification of conjugation-ready oligosaccharides have been established. Introduction of methods to install selectively a wide variety of glycosidic linkages has enabled the rapid assembly of linear and branched oligo- and polysaccharides as large as 30-mers. Fast, reliable access to defined glycans that are ready for conjugation has given rise to glycan arrays, glycan probes, and synthetic glycoconjugate vaccines. While an ever increasing variety of glycans are accessible by automated synthesis, further methodological advances in carbohydrate chemistry are needed to make all possible glycans found in nature. These tools begin to fundamentally impact the medical but also materials aspects of the glycosciences.

Pathogen-Derived Oligosaccharides Improve Innate Immune Response to Intracellular Parasite Infection

Pathogen glycolipids, including Leishmania spp. lipophosphoglycan (LPG) and Mycobacterium tuberculosis mannosylated lipoarabinomannan (ManLAM), modulate essential interactions with host phagocytic cells. Polysaccharide and lipid components promote immunomodulation. Owing to the stereochemistry required to synthesize oligosaccharides, the roles for oligosaccharides in the pathogenesis of infectious diseases have remained largely unknown. Recent advances in carbohydrate chemistry allowed us to synthesize pathogen surface oligosaccharides to discern their immune response-altering activities. Trimannose cap carbohydrates from ManLAM and LPG altered the production of proinflammatory cytokines via a toll-like receptor (TLR2)-mediated mechanism in vitro and in vivo. In vivo treatment with trimannose led to increased Th1-polarizing, IL-12p40-producing cells from the draining lymph nodes of treated Leishmania major-infected mice compared with cells from untreated infected mice. Trimannose treatment increased the production of other Th1 proinflammatory cytokines (ie, interferon-γ, IL-6, and tumor necrosis factor-α) critical for a productive immune response to either pathogen. This significant difference in cytokine production between trimannose cap sugar-treated and control groups was not observed in draining lymph node cells from TLR2(-/-) mice. Type of inflammation and rate of bead entry into macrophages and dendritic cells were different for trimannose-coated beads compared with control oligosaccharide-coated beads, indicating selective lectin receptor/oligosaccharide interactions mediating cell entry and cytokine production. These novel findings may prompt the development of targeted oligosaccharide adjuvants against chronic infections.

Carbohydrate Research in the 20th Century

Robert V. Stick is a carbohydrate chemist; and so am I. Carbohydrate chemistry is a special branch of organic chemistry. The carbohydrates differ from the common organic chemicals in many ways: they do not dissolve in organic solvents, they cannot be distilled; and when a pure sugar is dissolved in water, a solution results that contains six different compounds. Carbohydrate chemists have their own journals and textbooks. Carbohydrate chemistry did not develop until the end of the 19th century; then Emil Fischer[1] determined the structures and configuration of all the simple sugars, established conversions, and studied their reactions. I worked for my Ph.D. degree in sugar chemistry with Zemplen, a former student of Fischer; he was not a brilliant chemist, and was a poor supervisor. When I completed my degree, I decided not to work on sugars any more: I thought that the problems there had already been solved by Fischer himself and his team. I went into the pharmaceutical industry. But soon I realised that my judgment was not right: there was plenty to learn still about the properties of sugars. Thus, we did not know why d-glucose is mainly in the β-pyranose form but d-mannose mainly the α-pyranose. Why does the equilibrium of d-glucose contains very little furanose but that of d-idose quite a lot? Why do some sugars readily form a 1,6-anhydride but others do not? When I obtained a university position in 1946, I returned to carbohydrate chemistry. In the middle of the century, three new methods revolutionized carbohydrate chemistry: NMR spectroscopy,[2] X-ray crystallography,[3] and conformational analysis.[4] NMR spectroscopy allowed the determination of the exact proportions of isomers in equilibrium; the X-ray method indicated the exact shapes of the molecules; and conformational analysis supplied the explanations and allowed predictions of behaviour. It became now much easier to deal with the structures and synthesis of complex carbohydrates, such as oligosaccharides and glycosides. And synthesis has been improved by new methods and new reagents, and by better control of conditions. Separation methods were also improved, for example chromatography – originally an analytical technique – was turned into an efficient method of preparative separation. When Stick established his group in the Department of Chemistry at the University of Western Australia his collaborators and Ph.D. students carried out a range of reactions with a variety of sugars. Many of the compounds thus obtained were natural products, but others were artefacts. These, of course, were compounds of interest to biochemists because they could be tested for potential biological activity. Soon many papers appeared on the biochemical behaviour of sugar derivatives. By now, there were biochemists in some chemistry departments and chemists in some biochemistry departments. Ideally, close cooperation was desired between them but, in fact, was seldom achieved. In most universities, the chemistry and the biochemistry departments are in different faculties and not even close to each other. [In my case, the two schools do not even inform each other of their seminars.] By contrast, by the time of the retirement of Robert Stick in 2008, his department had been renamed the School of Biomedical, Biomolecular and Chemical Sciences. The changes in carbohydrate chemistry are easily surveyed by looking at two sources of information: the series Advances in Carbohydrate Chemistry, published annually since 1945, and the programs of the International Symposia on Carbohydrate Chemistry, held biennially since 1960. The Advances contain chapters of current interest on carbohydrates; the symposia consist of talks on subjects in which work was currently carried out. Both indicate which way carbohydrate research is moving. Both organizations realised how much it was tending towards biochemistry. In 1989 Advances in Carbohydrate Chemistry added the words ‘and Biochemistry’ to its title; in 1980, the Symposia made room for biochemistry in the opposite way by omitting in Vancouver the word ‘Chemistry’ and becoming International Carbohydrate Symposia. Neither of these bodies used the term ‘Glycoscience’, much liked by some of the biochemists. [However, a recent book on carbohydrate chemistry and biochemistry is entitled Glycoscience; Chemistry and Chemical Biology. It contains more than 9000 references!] At the Symposium in Hamburg (in 2000), about one-third of the presented papers and the posters were on biochemistry and biotechnology. By then, interest in carbohydrates had grown very much: there were almost 1000 talks and posters presented. At the latest Symposium, in 2007 in Oslo, again about onethird of the papers and posters were on biochemical subjects. Curiously, the proportion was smaller for the plenary and invited lectures; apparently there were few biochemists on the organizing committee. Unfortunately, Robert Stick missed this meeting, his first absence in over 20 years. All this development affected Robert Stick’s interest and research too. Most of his work was published in the Australian Journal of Chemistry but gradually shifted to journals of

Surface glycans of Candida albicans and other pathogenic fungi: physiological roles, clinical uses, and experimental challenges.

Although fungi have always been with us as commensals and pathogens, fungal infections have been increasing in frequency over the past few decades. There is a growing body of literature describing the involvement of carbohydrate groups in various aspects of fungal disease. Carbohydrates comprising the cell wall or capsule, or as a component of glycoproteins, are the fungal cell surface entities most likely to be exposed to the surrounding environment. Thus, the fungus-host interaction is likely to involve carbohydrates before DNA, RNA, or even protein. The interaction between fungal and host cells is also complex, and early studies using whole cells or crude cell fractions often produced seemingly conflicting results. What was needed, and what has been developing, is the ability to identify specific glycan structures and determine how they interact with immune system components. Carbohydrate analysis is complicated by the complexity of glycan structures and by the challenges of separating and detecting carbohydrates experimentally. Advances in carbohydrate chemistry have enabled us to move from the foundation of composition analysis to more rapid characterization of specific structures. This, in turn, will lead to a greater understanding of how fungi coexist with their hosts as commensals or exist in conflict as pathogens.

Complex Carbohydrates in Drug Development

Publisher SummaryRecent advances in carbohydrate chemistry and biochemistry afford the opportunity to develop bioactive complex carbohydrates, per se, as drugs or as lead compounds in drug development. Complex carbohydrates are unique among biopolymers in their inherent potential to generate diverse molecular structures. While proteins vary only in the linear sequence of their monomer constituents, individual monosaccharides can combine at any of several sites on each carbohydrate ring, in linear or branched arrays, and with varied stereochemistry at each linkage bond. This chapter addresses some salient features of mammalian glycoconjugate structure and biosynthesis, and presents examples of the biological activities of complex carbohydrates. The chapter presents selected examples that will provide an accurate introduction to their pharmacological potential. In addition to their independent functions, oligosaccharides can modify the activities of proteins to which they are covalently attached. Many glycoprotein enzymes and hormones require glycosylation for expression and function. The chapter discusses the ancillary role of carbohydrates that is of great importance to the use of engineered glycoproteins as pharmaceuticals.

Advances in Carbohydrate Chemistry and Biochemistry Volume 42, edited by R. Stuart Tipson and Derek Horton, Academic Press, Orlando, FL, and London, U.K., 1984, xii + 394 pages + Author and Subject Indexes, $65.00, £49.00

Advances in Carbohydrate Chemistry and Biochemistry Volume 42, edited by R. Stuart Tipson and Derek Horton, Academic Press, Orlando, FL, and London, U.K., 1984, xii + 394 pages + Author and Subject Indexes, $65.00, £49.00

Advances in Carbohydrate Chemistry.

Advances in Carbohydrate Chemistry.

Advances in carbohydrate chemistry. Volume 13

Advances in carbohydrate chemistry. Volume 13

The Moving Front of Carbohydrates

Advances in Carbohydrate Chemistry, Vol. 13 Edited by Melville L. Wolfrom in association with R. Stuart Tipson. Pp. xi + 387. (New York: Academic Press, Inc.; London: Academic Books, Ltd., 1958.) 88s.

Advances in carbohydrate chemistry. Volume 10

Advances in carbohydrate chemistry. Volume 10

Advances in Carbohydrate Chemistry.

Advances in Carbohydrate Chemistry.

Advances in carbohydrate chemistry. Volume IX

Advances in carbohydrate chemistry. Volume IX

Advances in Carbohydrate Chemistry.

Advances in Carbohydrate Chemistry.

Advances in Carbohydrate Chemistry.

Advances in Carbohydrate Chemistry.

Advances in carbohydrate chemistry. Volume VII

Advances in carbohydrate chemistry. Volume VII

Advances in Carbohydrate Chemistry. Volume VI

ADVERTISEMENT RETURN TO ISSUEPREVBook and Media Revie...Book and Media ReviewNEXTAdvances in Carbohydrate Chemistry. Volume VIIrwin B. Douglass Cite this: J. Chem. Educ. 1953, 30, 2, 103Publication Date (Print):February 1, 1953Publication History Received3 August 2009Published online1 February 1953Published inissue 1 February 1953https://doi.org/10.1021/ed030p103.1RIGHTS & PERMISSIONSArticle Views85Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

Advances in carbohydrate chemistry. Volume V

Advances in carbohydrate chemistry. Volume V