Characterization of neutral sugars and uronic acids after methanolysis and trimethylsilylation for recognition of plant gums

Bleton, Jean; Mejanelle, P.; Sansoulet, J.; Goursaud, S.; Tchapla, Alain

doi:10.1016/0021-9673(95)00308-8

Cited by 115 publications

(69 citation statements)

References 25 publications

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“…Small-scale hydrolyses were performed in the same fashion to the point of silica gel purification. These syrups were subjected directly to trimethylsilylation (3) and GC analysis (specifics: GC-17A GC [ (6,30). 2-Chloropropionic acid (R or S enantiomers; 260 l) was added after 30 min, and the solution was stirred at 65°C overnight.…”

Section: Methodsmentioning

confidence: 99%

Structural Characterization of the Released Polysaccharide of Desiccation-Tolerant Nostoc commune DRH-1

et al. 2000

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The microfossil record suggests that cyanobacteria or cyanobacteria-like prokaryotes were present on the primitive Earth in the Archaean era more than 3.5 billion years ago (28). The exquisite preservation of these microfossils is thought to reflect the intrinsic stability of the extracellular polysaccharide (EPS) and its ability to bind heavy metals as well as resist degradation (13). Extant cyanobacteria dominate the microbial populations of many extreme environments including soda lakes (Spirulina, Cyanospira), the nutrient-poor open ocean (Trichodesmium), thermal springs (Synechococcus and Mastigocladis), and the cold dry polar deserts (Chroococcidiopsis) (35). In these environments the cyanobacteria produce copious amounts of EPSs in the form of sheaths, slimes, and capsules. Very little is known about the diversity, mode of synthesis, structure, or properties of these biopolymers (19). A recent review emphasized the potential role of EPSs in the desiccation tolerance of prokaryotes (23). However, much further research is needed to resolve the specific mechanisms which biopolymers contribute to such a complex process.The terrestrial cyanobacterium Nostoc commune has a marked capacity for desiccation tolerance and can survive storage at Ϫ400 MPa (0% relative humidity) for centuries (23). The cells produce large amounts of an unusual excreted polysaccharide that contributes in at least four ways to the marked stabilization of cells during prolonged storage in the air-dried state, at low or high temperatures. First, the glycan inhibits fusion of membrane vesicles during desiccation and freezedrying (10) and acts as an immobilization matrix for a range of secreted enzymes which remain fully active after long-term air-dried storage (11,27,32). Second, the glycan provides a structural and/or molecular scaffold with rheological properties which can accommodate the rapid biophysical and physiological changes in the community upon rehydration and during recovery from desiccation. The glycan swells from brittle dried crusts to cartilaginous structures within minutes of rehydration. Third, the glycan matrix contains both lipid-and watersoluble UV radiation-absorbing pigments which protect the cell from photodegradation (12). Fourth, although epiphytes colonize the surfaces of Nostoc colonies, there is no penetration of the glycan due in part to a silicon-and calcium-rich pellicle and inherent resistance of the glycan to enzymatic breakdown. Preliminary structural work on one water-soluble UV-absorbing pigment (released from the glycan by acid hydrolysis) indicated the presence of an oligosaccharide (4), raising the possibility that the pigment may be covalently linked to the glycan in the desiccated state.An understanding of the biochemical and biophysical properties of such biopolymers and the isolation of genes and enzymes required for their synthesis and modification can lead to an understanding of the underlying principles of extremophile stability. Furthermore, one can envision the utilization of such materials f...

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Section: Methodsmentioning

confidence: 99%

Structural Characterization of the Released Polysaccharide of Desiccation-Tolerant Nostoc commune DRH-1

et al. 2000

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“…These could relate to apparent use of beeswax in the preparation of this mummy although, as reported for two votives analysed by Buckley et al (2004), they could also derive from a natural plant gum or gum-resin. Further work investigating the presence of saccharides is currently being undertaken using a water extraction (after Bleton et al, 1996;Ménager et al, 2014). These results will be published in due course if they add to our understanding of the substances used in the treatment of these votive bundles.…”

Section: Resinous Plant Exudatesmentioning

confidence: 99%

“…Figure 2 Protocol developed to facilitate the selection of samples from Egyptian votive animal mummies and maximize the structural and molecular information obtained from these sensitive artefacts without causing further damage. The scheme includes ongoing work to evaluate the saccharide content of these samples, based on the FTIR method of Ménager et al (2014)* and GC-MS method of Bleton et al (1996). ** When in sufficient abundance, oil/fat components will be analysed in future investigations using GC-C-IRMS (after Evershed, 2009 During the Late Period, influenced by the upheaval resulting from a series of external conquests and exposure to new ritual practices, this practice appears to have evolved to include the concept of votive mummies (Ikram, 2005).…”

Section: Archaeological Contextmentioning

confidence: 99%

Organic residue analysis of Egyptian votive mummies and their research potential

Brettell

Martin

Atherton-Woolham

et al. 2016

Studies in Conservation

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Vast numbers of votive mummies were produced in Egypt during the Late Pharaonic, Ptolemaic, and Roman periods. Although millions remain in situ, many were removed and have ultimately entered museum collections around the world. There they have often languished as uncomfortable reminders of antiquarian practices with little information available to enhance their value as artefacts worthy of conservation or display. A multi-disciplinary research project, based at the University of Manchester, is currently redressing these issues. One recent aspect of this work has been the characterization of natural products employed in the mummification of votive bundles. Using gas chromatography-mass spectrometry and the well-established biomarker approach, analysis of 24 samples from 17 mummy bundles has demonstrated the presence of oils/fats, natural waxes, petroleum products, resinous exudates, and essential oils. These results confirm the range of organic materials employed in embalming and augment our understanding of the treatment of votives. In this first systematic initiative of its kind, initial findings point to possible trends in body treatment practices in relation to chronology, geography, and changes in ideology which will be investigated as the study progresses. Detailed knowledge of the substances used on individual bundles has also served to enhance their value as display items and aid in their conservation.

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“…As for most TMS derivatives in EI-MS, small M-15 ions are identified and m/z 103 ((CH3)3SiOCH2 + ) and m/z (nx102)+1 (n being the number of carbon atoms in the chain of the alditol fragment) are recorded with their corresponding ion coming from a loss of 90 amu ((CH3)3SiOH). Monosaccharides can also be analyzed prior to reduction by NaBH4 or NaBD4, under their cyclic forms, but the chromatograms are more complicated due to the hemiacetal group in sugars which leads to multiple structures [29].…”

Section: Quality and Relative Quantities Of Monosaccharides: Alditol mentioning

confidence: 99%

Coupled Mass Spectrometric Strategies for the Determination of Carbohydrates at Very Low Concentrations: The Case of Polysaccharides Involved in the Molecular Dialogue Between Plants and Rhizobia

Poinsot¹,

Carpéné²,

Couderc³

2012

The Complex World of Polysaccharides

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Characterization of neutral sugars and uronic acids after methanolysis and trimethylsilylation for recognition of plant gums

Cited by 115 publications

References 25 publications

Structural Characterization of the Released Polysaccharide of Desiccation-Tolerant Nostoc commune DRH-1

Structural Characterization of the Released Polysaccharide of Desiccation-Tolerant Nostoc commune DRH-1

Organic residue analysis of Egyptian votive mummies and their research potential

Coupled Mass Spectrometric Strategies for the Determination of Carbohydrates at Very Low Concentrations: The Case of Polysaccharides Involved in the Molecular Dialogue Between Plants and Rhizobia

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