Deoxysugar Research Articles

Major biochemical composition of dissolved high molecular weight organic matter in seawater

Abstract Ultrafiltered dissolved organic matter (UDOM) was isolated from surface, oxygen minimum, and deep waters of three ocean basins and its elemental as well as molecular-level aldose and amino acid compositions were determined. Surface concentrations account for 23–33% of total dissolved organic carbon, and are a factor of 2–3 greater than those in deeper waters. Oceanic UDOM has an extremely characteristic organic composition, clearly distinct from other marine materials such as fresh plankton, sinking particles or humic substances. Polysaccharides appear to be the major reactive component of UDOM. They have a distinctive aldose distribution rich in galactose and deoxy sugar that is almost ubiquitous regardless of depth or location, suggesting that UDOM carbohydrate is dominated by a very similar suite of polysaccharide throughout the ocean. In contrast, amino acids account for a relatively minor component of both total UDOM and of its organic nitrogen component. Amino acid distributions are similar to those from unfractionated seawater, and are not preferentially remineralized. In O2 minimum and deep ocean water, ultrafiltered material accounts for 18–25% of total dissolved organic carbon. Compositions are nearly invariant in these subsurface isolates, suggesting that ultrafiltered material is stable and unreactive throughout the subsurface ocean. Taken together with large compositional differences between UDOM and sinking particles, this observation suggests that dynamic aggregation is probably not an important formation or removal process for UDOM in the deep ocean. Amino acid and especially carbohydrate concentrations are lower in deep UDOM, but the overall molecular-level compositions remain similar to those from surface waters. This molecular-level homogeneity suggests that the UDOM biopolymers reflected in amino acid and carbohydrate data persist relatively unaltered in the deep ocean.

ChemInform Abstract: A Highly Sensitive HPLC Method to Discriminate Enantiomeric Amino Deoxy Sugars Based on the Derivatization with (S)‐(+)‐TBMB Carboxylic Acid.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Combined Enzymatic Synthesis of Nucleotide (Deoxy) Sugars from Sucrose and Nucleoside Monophosphates.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Preparation of Deoxy Sugars via Aldolase‐Catalyzed Synthesis of 1‐ Deoxy‐1‐thioketoses.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Substrate specificity of native dTDP-?-glucose-4,6-dehydratase: chemo-enzymatic syntheses of artificial and naturally occurring deoxy sugars

Substrate specificity of native dTDP-?-glucose-4,6-dehydratase: chemo-enzymatic syntheses of artificial and naturally occurring deoxy sugars

Substrate specificity of native dTDP- d-glucose-4,6-dehydratase: Chemo-enzymatic syntheses of artificial and naturally occurring deoxy sugars

Incubation of dTDP-glucose with the enzyme dTDP-glucose-4,6-dehydratase [EC 4.2.1.46] from wild type E. coli B yielded a mixture of 3- and 4-keto-6-deoxy sugars after work-up. Model experiments with chemically synthesized methyl 6-deoxy-4-keto-glucoside ( 9) revealed that dTDP-6-deoxy-α-d- ribo-hexopyran-3-ulose ( 3) is formed by keto-enol tautomerization during the isolation procedure from initially formed dTDP-6-deoxy-α-d- xylo-hexopyran-4-ulose ( 2). dTDP-3-deoxyglucose ( 4) and dTDP-3-azido-3-deoxyglucose ( 6) were substrates and showed Michaelis-Menten kinetics ( 4: K M = 200 μM and V max = 130 μmol/hmg; 6: K M = 300 μM and V max = 90 μmol/hmg). In 100-mg-scale experiments, both non-natural substrates gave the respective 6-deoxy-4-keto compounds, dTDP-3,6-dideoxy-α-d- erythro-hexopyran-4-ulose ( 5) and dTDP-3-azido-3,6-dideoxy-α-d- xylo-hexopyran-4-ulose ( 7), in yields ranging from 24 to 40%.

Combined enzymatic synthesis of nucleotide (deoxy) sugars from sucrose and nucleoside monophosphates

The synthesis of NDP-glucose 3a-d (NA, C, U, dU) with sucrose synthase B was combined with the enzymatic synthesis of nucleoside diphosphates 2a-d from their corresponding nucleoside monophosphates 1a-d by different kinases A. Further combination with recombinant dTDP-glucose 4,6-dehydratase D enabled us to synthesize dUDP-6-deoxy-α-D- xylo-4-hexulose 5 from 1d on a preparative scale. By using the repetitive batch technique the enzymatic syntheses of nucleotide (deoxy) sugars 3a-d, 5 could be realized on a 0.1 – 0.5 g scale.

A Highly Sensitive HPLC Method to Discriminate Enantiomeric Amino Deoxy Sugars Based on the Derivatization With (S) - (+)-Tbmb Carboxylic Acid

Abstract A picomole determination of the absolute configurations of amino deoxy sugars was demonstrated through the derivatization at the anomeric carbon with a fluorescent chiral reagent, (S)-(+)-TBMB carboxylic acic, followed by the HPLC separations of the derived diastereomeric isomers. A new chemical procedure was developed to convert amino deoxy sugars into per-NH,O-acetylated glycosyl chlorides prior to derivatization with the reagent.

Biochemical characterization of lipopolysaccharides extracted from a hydrophobic strain of Pasteurella multocida.

Lipopolysaccharides were extracted from freeze-dried cells of Pasteurella multocida strain P-1581 (serotype 8) by the phenol-chloroform-petroleum ether method and biochemically analysed using standard procedures. The primary neutral sugars were glucose, galactose and heptose. No deoxy sugars were detected. Amino sugars included galactosamine, glucosamine and glucosamine-6-phosphate. 3-Deoxy-D-manno-2-octulosonic acid was present at a relatively low concentration. The analyses included identification and quantification of phosphate and alanine. The primary fatty acids and their approximate relative ratios were 3-hydroxytetradecanoate and tetradecanoate 2:1. Tetradecanoic acid was bound almost exclusively by ester linkages. 3-Hydroxytetradecanoic acid was bound primarily by amide linkages, although significant numbers of ester-bound residues were noted. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analyses indicated that the lipopolysaccharides were of low molecular weight.

Preparation of Deoxy Sugars via Aldolase-Catalyzed Synthesis of 1-Deoxy-1-thioketoses.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTPreparation of Deoxy Sugars via Aldolase-Catalyzed Synthesis of 1-Deoxy-1-thioketosesRachel Duncan and Dale G. DrueckhammerView Author Information Department of Chemistry, Stanford University, Stanford, California 94305 Cite this: J. Org. Chem. 1996, 61, 2, 438–439Publication Date (Web):January 26, 1996Publication History Received14 November 1995Published online26 January 1996Published inissue 1 January 1996https://doi.org/10.1021/jo9520093Copyright © 1996 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views249Altmetric-Citations19LEARN 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 Read OnlinePDF (106 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Aldehydes,Aldol reactions,Anions,Carbohydrates,Hydrolysis Get e-Alerts

Screening for cardiac glycosides in Schizobasis intricata

Traditional herbalists in Natal use Schizobasis intricata (Bak.) Bak, as a substitute for Bowiea volubilis Harv. ex Hook. This may be due to morphological confusion of the two species or they may elicit a similar biological response. Bowiea bulbs are known to contain cardiac glycosides. A phytochemical screening of S. intricata for cardiac glycosides was carried out, S. intricata contains 2-deoxy sugars, common components in the sugar moieties of cardiac glycosides, Comparative chromatographic screening showed that S. intricata bulbs do not contain cardenolides nor any Bowiea -type bufadienolides. Other unknown bufadienolides may, however, be present In this plant. Tradisionele kruiedoktors in Natal gebruik Schizobasis intricata (Bak.) Bak. as ’n altematief vir Bowiea volubilis Harv. ex Hook. Dit mag die gevolg wees van morfologiese verwarring of die twee spesies mag dieselfde biologiese reaksie tot gevolg hê. Dit is bekend dat Bowiea kardiale glikosiede bevat. ’n Fitochemiese ondersoek is gedoen op S. intricata vir kardiale glikosiede, S. intricata bevat 2-deoksi-suikers, ’n algemene komponent van kardiale glikosiede. Vergelykende chromatografiese ondersoeke het getoon dat S. intricata bolle nie kardenoliede of enige Bowiea- tipe bufadiëno-liede bevat nie. Ander onbekende bufadiënoliede mag egter in hierdie plant teenwoordig wees.

ChemInform Abstract: One‐Pot‐Synthesis of α‐Linked Deoxy Sugar Trisaccharides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Analysis of oligosaccharides containing 2-deoxy-α- d- arabino-hexosyl residues by the reductive-cleavage method

A mixture of oligosaccharides containing (1→4)-linked 2-deoxy-α- d- arabino-hexosyl (“2-deoxyglucosyl”) and (1→4)-linked α- d-glucosyl residues ( 1) was analyzed by reduction, permethylation (perethylation), degradation to monomers, and GLC-MS. Degradation was performed either by hydrolysis with subsequent reduction, by methanolysis, or by reductive cleavage, always followed by acetylation. Reductive cleavage turned out to be the method of choice for the acid-labile 2-deoxy sugars. The main degradation product formed during acid hydrolysis of 2-deoxy- d- arabino-hexosyl residues yielded, after reduction and acetylation, (4 R,S)-6- O-acetyl-2,3,5-trideoxyhexono-1,4-lactone ( 7). By methanolysis, in addition to the expected methyl glycosides, methyl 2,3,5-trideoxy-6- O-methyl-4-hexulosonate ( 12) is formed as a by-product. For determination of the distribution of chain lengths, the permethylated oligomers were separated by reversed-phase HPLC. For peak assignment, one isolated oligomer was investigated by FABMS and 1H NMR spectroscopy. The average degree of polymerization (dp) calculated from the HPLC chromatogram is in good agreement with the reductive-cleavage results.

Pathways and mechanisms in the biogenesis of novel deoxysugars by bacteria.

Science has long recognized the ubiquitously occurring deoxysugars as a novel and important class of carbohydrate, by virtue of the variety of potent and intriguing biological activities they exhibit. The study of the biosynthesis of these naturally vital molecules at a molecular level has received a great deal of attention in recent years, whether it be the well-established study of deoxyribonucleotide biosynthesis via ribonucleotide reductase or newer areas that include 3,6-dideoxyhexose construction and O antigen variation, as well as the emerging scrutiny of the biosynthesis of deoxysugar ligands of antibiotics and cardiac glycosides. This review attempts to update the various classes of deoxy, dideoxy, trideoxy, branched-chain, and amino sugars with respect to our current knowledge regarding the vast biological activities, genetics of formation, and molecular basis of their biosynthesis. In particular, the primary focus utilizes CDP-ascarylose biosynthesis, currently the best genetically and biochemically characterized dideoxysugar system, as a basis for comparison and postulation. This review helps display the elegant complexities of these essential natural saccharides and speculates upon tomorrow's potential applications.

Utility of glycosyl phosphites as glycosyl donors-fructofuranosyl and 2-deoxyhexopyranosyl phosphites in glycoside bond formation

The discussion of the ease of generating glycosyl donor properties in the important sugar categories (aldoses, ketoses, deoxy sugars, sugar uronates, and 3-deoxy-2-glyculosonates) implies that phosphites of ketoses and deoxy sugars, respectively, should be valuable donors. This is exhibited for fructofuranosyl phosphite 2 and for 2-deoxyhexopyranosyl phosphites 14a,b which are readily available and generally provide disaccharides in high yields.

One-pot-synthesis of α-linked deoxy sugar trisaccharides

Various α-linked 2,6-dideoxy- ribo-trisaccharides, models for part of the antibiotic kijanimicin, were synthesised by the N-iodosuccinimide method employing different pathways. The efficiency of a sequential synthesis suffered from side reactions of the axial HO-3, which are typical of digitoxosides. These problems did not arise in a straightforward polymerisation, performed as a one-pot-procedure. It afforded the trisaccharide directly from the monosaccharide precursor in 30% yield. A combination of the oligomerisation pathway and the sequential synthesis led to trisaccharides with different protecting group patterns. In these reactions different glycal and alcohol components were used and allowed to define the optimal partners in a sequential synthesis: the two components should ideally be of comparable reactivity.

Origins and processing of organic matter in the Amazon River as indicated by carbohydrates and amino acids

Aldose, amino acid, and elemental compositions were determined for flux‐weighted samples of coarse (>63 µm) and fine (<63 µm) particulate organic material and ultrafiltered (>1,000 Daltons) dissolved organic matter collected at three sites along the Brazilian Amazon River and six of its major tributaries. Concentrations of total organic C (TOC) were relatively uniform (550±100 µM) at all sites, with DOC comprising the major (50–100%) component. An average of 77% of the total DOC was isolated by ultrafiltration.The greatest compositional differences observed in the Amazon River system were among the coarse, fine, and dissolved organic fractions. All coarse particulate fractions were nitrogen‐poor (atomic C : N = 21) and exhibited stable carbon isotope, aldose, and amino acid compositions similar to those of angiosperm tree leaves. Coarse particulate organic materials, although the least degraded of the three fractions, had lost appreciable carbohydrate and had immobilized excess nitrogen of apparent bacterial origin. Fine particulate materials were more nitrogen‐rich (C : N = 9) than coarse counterparts and had lower total aldose yields and glucose percentages. Fine particles gave greater total yields of amino acids, characterized by high ratios of basic vs. acidic components. Coexisting dissolved organic materials recovered by ultrafiltration were nitrogen‐poor (C : N = 27–52) and yielded the lowest amounts of aldoses, among which deoxy sugars were concentrated. Dissolved fractions gave extremely low yields of amino acids in mixtures that were enriched in nonprotein components and in acidic vs. basic molecules. These yield and composition patterns are consistent with a “regional chromatography” model in which highly degraded leaf material is solubilized and then partitioned between soil minerals and water during transport to the river, resulting in suspended fine particulate organic materials of soil origin that are nitrogen‐rich and coexisting dissolved organic substances that are nitrogen‐poor.

A new stereoselective route to branched-chain nitro and amino sugars: synthesis of both enantiomers of decilonitrose and avidinosamine

Short, efficient, and highly diastereoselective syntheses of the title carbohydrates (15, 21, and 22), components of new anthracycline antibiotics, on a gram scale from readily available keto sugar precursors 6 and 17 are described. The syntheses feature the smooth and clean addition of organocerium compounds to benzyloxyimino derivatives 7 and 18; which provide the branched-chain hydroxyamino sugars (9, 20) bearing an equatorial methyl group with complete regio- and stereocontrol. Treatment of oximino deoxy sugars (7, 18) with methyllithium resulted in β-elimination and afforded pyranoid 1-enol 3-one oximes (8, 19)

Synthesis of Some Specifically Deoxygenated D-Hexopyranosyl Phosphates

Abstract A number of diphenyl α-glucopyranosyl and xylopyranosyl phosphates (4, 7, 11. 15, 19, and 25) were prepared from their respective glycosyl chlorides by reaction with silver diphenyl phosphate. These sugar phosphates are of interest as enzyme substrates in deoxy sugar biosynthesis.

Photochemical Reactions of Carbohydrate Triflates

AbstractThe photochemical reactions of eight carbohydrate trifluoromethanesulfonates (triflates) have been investigated in methanol in the presence of potassium iodide. For those compounds which do not contain an aromatic chromophore, photolysis results in two types of reaction. One type produces deoxy sugars by replacement of the trifluoromethylsulfonyloxy (triflyloxy) group with a hydrogen atom. The second type of reaction generates partially protected sugars by replacement of the trifluoromethylsulfonyl (triflyl) group with a hydrogen atom. When the triflate being irradiated also has a protecting group containing an aromatic ring (i.e., benzyl, benzoyl, or p-tolylsulfonyl group), removal of the protecting group is the exclusive reaction pathway.