Glycosyl-residue Composition Analyses Research Articles

Glycome Profiling and Bioprospecting Potential of the Himalayan Buddhist Handmade Paper of Tawang Region of Arunachal Pradesh.

The paper and pulp industry (PPI) is one of the largest industries that contribute to the growing economy of the world. While wood remains the primary raw material of the PPIs, the demand for paper has also grown alongside the expanding global population, leading to deforestation and ecological imbalance. Wood-based paper production is associated with enormous utilization of water resources and the release of different wastes and untreated sludge that degrades the quality of the environment and makes it unsafe for living creatures. In line with this, the indigenous handmade paper making from the bark of Daphne papyracea, Wall. ex G. Don by the Monpa tribe of Arunachal Pradesh, India is considered as a potential alternative to non-wood fiber. This study discusses the species distribution modeling of D. papyracea, community-based production of the paper, and glycome profiling of the paper by plant cell wall glycan-directed monoclonal antibodies. The algorithms used for ecological and geographical modeling indicated the maximum predictive distribution of the plant toward the western parts of Arunachal Pradesh. It was also found that the suitable distribution of D. papyracea was largely affected by the precipitation and temperature variables. Plant cell walls are primarily made up of cellulose, hemicellulose, lignin, pectin, and glycoproteins. Non-cellulosic cell wall glycans contribute significantly to various physical properties such as density, crystallinity, and tensile strength of plant cell walls. Therefore, a detailed analysis of non-cellulosic cell wall glycan through glycome profiling and glycosyl residue composition analysis is important for the polymeric composition and commercial processing of D. papyracea paper. ELISA-based glycome profiling results demonstrated that major classes of cell wall glycans such as xylan, arabinogalactans, and rhamnogalacturonan-I were present on D. papyracea paper. The presence of these polymers in the Himalayan Buddhist handmade paper of Arunachal Pradesh is correlated with its high tensile strength. The results of this study imply that non-cellulosic cell wall glycans are required for the production of high-quality paper. To summarize, immediate action is required to strengthen the centuries-old practice of handmade paper, which can be achieved through education, workshops, technical know-how, and effective marketing aid to entrepreneurs.

Comparison of four glycosyl residue composition methods for effectiveness in detecting sugars from cell walls of dicot and grass tissues

BackgroundThe effective use of plant biomass for biofuel and bioproduct production requires a comprehensive glycosyl residue composition analysis to understand the different cell wall polysaccharides present in the different biomass sources. Here we compared four methods side-by-side for their ability to measure the neutral and acidic sugar composition of cell walls from herbaceous, grass, and woody model plants and bioenergy feedstocks.ResultsArabidopsis, Populus, rice, and switchgrass leaf cell walls, as well as cell walls from Populus wood, rice stems, and switchgrass tillers, were analyzed by (1) gas chromatography–mass spectrometry (GC–MS) of alditol acetates combined with a total uronic acid assay; (2) carbodiimide reduction of uronic acids followed by GC–MS of alditol acetates; (3) GC–MS of trimethylsilyl (TMS) derivatives; and (4) high-pressure, anion-exchange chromatography (HPAEC). All four methods gave comparable abundance ranking of the seven neutral sugars, and three of the methods were able to quantify unique acidic sugars. The TMS, HPAEC, and carbodiimide methods provided comparable quantitative results for the specific neutral and acidic sugar content of the biomass, with the TMS method providing slightly greater yield of specific acidic sugars and high total sugar yields. The alditol acetate method, while providing comparable information on the major neutral sugars, did not provide the requisite quantitative information on the specific acidic sugars in plant biomass. Thus, the alditol acetate method is the least informative of the four methods.ConclusionsThis work provides a side-by-side comparison of the efficacy of four different established glycosyl residue composition analysis methods in the analysis of the glycosyl residue composition of cell walls from both dicot (Arabidopsis and Populus) and grass (rice and switchgrass) species. Both primary wall-enriched leaf tissues and secondary wall-enriched wood/stem tissues were analyzed for mol% and mass yield of the non-cellulosic sugars. The TMS, HPAEC, and carbodiimide methods were shown to provide comparable quantitative data on the nine neutral and acidic sugars present in all plant cell walls.

Complex Carbohydrates of Red Wine: Characterization of the Extreme Diversity of Neutral Oligosaccharides by ESI-MS

The major neutral oligosaccharides of a Carignan red wine have been characterized for the first time. The oligosaccharides were prepared after removal of phenolic compounds by polyamide chromatography and of polysaccharides by alcohol precipitation and then were fractionated by anion exchange and size-exclusion chromatography. In a second step, the glycosyl composition and linkages of wine oligosaccharides were determined. Oligosaccharide fractions were analyzed by mass spectrometry (MS) with an electrospray ionization (ESI) source and an ion trap mass analyzer after separation by hydrophilic interaction liquid chromatography on a Nucleodur HILIC column (zwitterionic sulfoalkyl betaine stationary phase). Glycosyl residue composition analysis showed the predominant presence of arabinose, with galactose, rhamnose, and mannose in lower proportion. Neutral oligosaccharides were present at a concentration of 185 mg/L in this wine. The MS spectra in the negative ion mode of the oligosaccharide fractions showed a series of oligosaccharidic structures corresponding to oligo-arabinans often linked to the basic unit α-l-Rhap-(1 → 4)-α-d-GalpA. The wine oligosaccharides identified correspond to arabino-oligosaccharides, rhamno-arabino-oligosaccharides, and different rhamnogalacturonan-arabino-oligosaccharides with DP ranging from 5 to 49, resulting from the degradation of grape cell wall pectins. Oligosaccharides have an extreme diversity, with more than 100 peaks detected in HPLC-ESI-MS spectra corresponding each to at least one oligosaccharidic structure.

Isolation of Carignan and Merlot red wine oligosaccharides and their characterization by ESI-MS

The oligosaccharides of Carignan and Merlot wines have been characterized for the first time. In a first step, this fraction was prepared after discoloration of the wines and was collected by elution on an HPSEC system. In a second step, the glycosyl composition and linkages of wine oligosaccharides were determined by several methods. High resolution MS spectra of the Carignan and Merlot oligosaccharide fractions were obtained on an AccuTOF mass spectrometer equipped with an electrospray ionization (ESI) source and a time-of-flight (TOF) mass analyser. Oligosaccharides were present at a concentration of 330 and 250 mg/L in Carignan and Merlot red wines, respectively. Glycosyl residue composition analysis showed the presence of mannose, arabinose, galactose, rhamnose, fucose, xylose, glucose, galacturonic acid, and glucuronic acid. We show that oligosaccharides are present in significant amounts in wines, that they result from the degradation of cell wall polysaccharides and that they have an extreme diversity, about 30 peaks in ESI–TOF spectra corresponding each to at least one oligosaccharidic structure. The ESI–TOF spectra in negative mode of the Carignan and Merlot oligosaccharides showed oligosaccharidic structures corresponding to oligogalacturonic acids, partially esterified by methyl group (trigalacturonic acid detected at m/ z 545, m/ z 559 and m/ z 573) or to the repetition of the basic unit [→4)-α- d-GalA p-(1→2)-α- l-Rha p-(1→] two ( m/ z 661), or three ( m/ z 983) times. These units can be substituted either by a hexose, or by a pentose, or by both, but also by deoxyhexose or uronic acid. The identification of [4-OMe-GlcA-[Xyl] 2-Xylitol] and [4-OMe-GlcA-[Xyl] 3-Xylitol] by MS n fragmentation performed on a mass spectrometer equipped with an ESI source and an ion trap mass analyser makes it possible to explain the presence of xylose in wines.

Improved procedures for the selective chemical fragmentation of rhamnogalacturonans

The structural characterization of branched rhamnogalacturonans (RGs) requires the availability of methods that selectively cleave the Rha p-(1→4)-α-GalA p linkage and thereby generate oligosaccharide fragments that are suitable for mass spectrometric and NMR spectroscopic analyses. Enzymic cleavage of this linkage is often ineffective, especially in highly branched RGs. Therefore, we have developed an improved chemical fragmentation method based on β-elimination of esterified 4-linked Gal pA residues. At least 85% of the carboxyl groups of the GalA residues in Arabidopsis thaliana seed mucilage RG is esterified using methyl iodide or 3-iodopropanol in Me 2SO containing 8% water and 1% tetrabutylammonium fluoride. However, β-elimination fragmentation at pH 7.3 and 120 °C is far more extensive with hydroxypropyl-esterified RG than with methyl-esterified RG. The non-reducing 4-deoxy-β- l - threo-hex-4-enepyranosyluronic acid residue formed by the β-elimination reaction is completely removed by treatment with aqueous N-bromosuccinimide, thereby simplifying the structural characterization of the chemically generated oligoglycosyl fragments. This newly developed procedure was used to selectively fragment the branched RG from peppergrass seed mucilage. The products were characterized using MALDI-TOF mass spectrometry, glycosyl residue composition analysis, and 1 and 2D NMR spectroscopy. Our data show that the most abundant low-molecular weight fragments contained a backbone rhamnose residue substituted at O-4 with a single sidechain, and suggest that peppergrass seed mucilage RG is composed mainly of the repeating unit 4-O-methyl-α- d-Glc pA-(1→4)-β- d-Gal p-(1→4)-[→4)-α- d-Gal pA-(1→2)-]-α- l-Rha p-(1→.

Moss and liverwort xyloglucans contain galacturonic acid and are structurally distinct from the xyloglucans synthesized by hornworts and vascular plants*

Xyloglucan is a well-characterized hemicellulosic polysaccharide that is present in the cell walls of all seed-bearing plants. The cell walls of avascular and seedless vascular plants are also believed to contain xyloglucan. However, these xyloglucans have not been structurally characterized. This lack of information is an impediment to understanding changes in xyloglucan structure that occurred during land plant evolution. In this study, xyloglucans were isolated from the walls of avascular (liverworts, mosses, and hornworts) and seedless vascular plants (club and spike mosses and ferns and fern allies). Each xyloglucan was fragmented with a xyloglucan-specific endo-glucanase and the resulting oligosaccharides then structurally characterized using NMR spectroscopy, MALDI-TOF and electrospray mass spectrometry, and glycosyl-linkage and glycosyl residue composition analyses. Our data show that xyloglucan is present in the cell walls of all major divisions of land plants and that these xyloglucans have several common structural motifs. However, these polysaccharides are not identical because specific plant groups synthesize xyloglucans with unique structural motifs. For example, the moss Physcomitrella patens and the liverwort Marchantia polymorpha synthesize XXGGG- and XXGG-type xyloglucans, respectively, with sidechains that contain a beta-D-galactosyluronic acid and a branched xylosyl residue. By contrast, hornworts synthesize XXXG-type xyloglucans that are structurally homologous to the xyloglucans synthesized by many seed-bearing and seedless vascular plants. Our results increase our understanding of the evolution, diversity, and function of structural motifs in land-plant xyloglucans and provide support to the proposal that hornworts are sisters to the vascular plants.

Polysaccharide Patterns During the Aging of Carignan noir Red Wines

A new method for the quantification of polysaccharides in wines has been applied to a series of Carignan noir red wines produced in 1996,1991,1989,1986,1981, and 1974. In parallel, the molecular weight distributions of polysaccharides have been followed by high-resolution size exclusion chromatography on a Superdex-75 HR column. Glycosyl-residue composition analyses revealed the presence of mannans, arabinogalactans, rhamnogalacturonans and galacturonans in all wines studied. Mannans were globally stable during the 23-year period studied, while the amount of pectic polysaccharides decreased slowly. Type II arabinogalactans and rhamnogalacturonan II decreased after approximately 15 years of storage. The homogalacturonan oligomers decreased dramatically during aging of wines. Small amounts of polysaccharides could be found in the insoluble pellet, indicating that slow hydrolytic phenomenon rather than solubilization may be involved in the slow decrease of polysaccharide concentration in wines.

Isolation and structural characterization of β- d-glucosyluronic acid and 4- O-methyl β- d-glucosyluronic acid-containing oligosaccharides from the cell-wall pectic polysaccharide, rhamnogalacturonan I

Rhamnogalacturonan I (RG-I), a pectic polysaccharide isolated from the walls of suspension-cultured sycamore cells, was shown by glycosyl-residue composition analysis to contain d-glucosyluronic acid (Glc pA) residues (1 mol%) and 4- O-methyl- d-glucosyluronic acid (4- O-Me-Glc pA) residues (0.5 mol%). These monosaccharides were shown, by glycosyl-linkage analysis, to be present in RG-I as terminal nonreducing residues. The glycosyl sequences containing Glc pA and 4- O-Me-Glc pA were determined by structurally characterizing the acidic oligosaccharides released by partial acid hydrolysis of RG-I. Six acidic oligosaccharides were purified by semipreparative high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and characterized by glycosyl-residue and glycosyl-linkage composition analyses, GLC-CIMS, GLC-EIMS, electrospray MS (ESMS), and 1H NMR spectroscopy. We propose that three of the acidic oligosaccharides characterized, 4- O-Me-β- d-Glc pA-(1 → 6)- d-Gal, β- d-Glc pA-(1 → 6- d-Gal, and β- d-Glc pA-(1 → 4)- d-Gal, originate from the galactosyl-containing side chains of RG-I. The three other acidic oligosaccharides characterized, α- d-Gal pA-(1 → 2)- l-Rha, α- d-Gal pA-(1 → 2)-α l-Rha p-(1 → 4)-α- d-Gal pA-(1 → 2)-α- l-Rha, and α- d-Gal pA-(1 → 2)-α- l-Rha p-(1 → 4)-α- d-Gal pA-(1 → 2)-α- l-Rha p-(1 → 4)-α- d-Gal pA-(1 → 2 )-α- l-Rha, were generated by partial hydrolysis of the RG-I backbone. No evidence was obtained for the presence of galactosyluronic acid in the side chains of RG-I. To our knowledge this is the first report that rhamnogalacturonan I contains glycosyluronic acid or 4- O-methyl glucosyluronic acid residues.

Purification and characterization of biologically active 1,4-linked α- d-oligogalacturonides after partial digestion of polygalacturonic acid with endopolygalacturonase

A procedure is described for generating and purifying biologically active (1 → 4)-linked α- d-oligogalacturonides (oligogalacturonides). Oligogalacturonides are generated by treatment of polygalacturonic acid (PGA) with a homogeneous fungal α-(1 → 4)-endopolygalacturonase (EPG). Oligogalacturonides with a dp greater than seven were selectively precipitated in the presence of sodium acetate and ethanol. Oligogalacturonides with a dp less than 11 and modified oligogalacturonides remained soluble. Oligogalacturonides with a dp between 10 and 15 were purified from the resolubilized NaOAc-ethanol-precipitated material using Q-Sepharose fast-flow anion-exchange chromatography followed by semipreparative high performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Approximately 70 mg of each homogeneous oligogalacturonide (dp between 10 and 15) was obtained from 10 g of EPG-treated PGA. The tridecagalacturonide fraction was selected for chemical and structural characterization and was shown to be homogeneous by glycosyl-residue composition analysis, HPAEC-PAD, FABMS, and 1H NMR spectroscopy. The purified tridecagalacturonide elicited phytoalexin accumulation in soybeans and induced flower formation and inhibited root formation in tobacco thin-cell-layer explants.