scholarly journals Solid-state NMR spectroscopic studies of 13C,15N,29Si-enriched biosilica from the marine diatom Cyclotella cryptica

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Felicitas Kolbe ◽  
Helena Leona Ehren ◽  
Simon Kohrs ◽  
Daniel Butscher ◽  
Lukas Reiß ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Organic Compounds ◽  
Solid State Nmr ◽  
Cell Walls ◽  
Organic Matrix ◽  
Marine Diatom ◽  
Distance Information ◽  
Silica Phase ◽  
Cyclotella Cryptica

AbstractDiatoms are algae producing micro- and nano-structured cell walls mainly containing amorphous silica. The shape and patterning of these cell walls is species-specific. Herein, the biosilica of Cyclotella cryptica, a centric marine diatom with a massive organic matrix, is studied. Solid-state NMR spectroscopy is applied to gain deeper insight into the interactions at the organic–inorganic interface of the cell walls. The various organic compounds like polysaccharides as well as proteins and long-chain polyamines (LCPAs) are detected by observation of heteronuclei like 13C and 15N whereas the silica phase is studied using 29Si NMR spectroscopy. The sensitivity of the NMR experiments is strongly enhanced by isotope-labeling of the diatoms during cultivation with 13C, 15N and 29Si. The presence of two different chitin species in the biosilica is demonstrated. This observation is supported by a monosaccharide analysis of the silica-associated organic matrix where a high amount of glucosamine is found. Moreover, the Rotational Echo Double Resonance (REDOR) experiment provides distance information for heteronuclear spins. 13C{29Si} REDOR experiments reveal proximities between different organic compounds and the silica phase. The closest contacts between silica and organic compounds appear for different signals in the 13C-chemical shift range of 40–60 ppm, the typical range for LCPAs.

scholarly journals Solid-state NMR spectroscopic studies of 13C,15N,29Si-enriched biosilica from the marine diatom Cyclotella cryptica

2020 ◽  
Author(s):  
Felicitas Kolbe ◽  
Helena Leona Ehren ◽  
Simon Kohrs ◽  
Daniel Butscher ◽  
Lukas Reiß ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Organic Compounds ◽  
Solid State Nmr ◽  
Cell Walls ◽  
Organic Matrix ◽  
Marine Diatom ◽  
Distance Information ◽  
Silica Phase ◽  
Cyclotella Cryptica

Abstract Diatoms are algae producing micro- and nano-structured cell walls mainly containing amorphous silica. The shape and patterning of these cell walls is species-specific. Herein, the biosilica of Cyclotella cryptica, a centric marine diatom with a massive organic matrix, is studied. Solid-state NMR spectroscopy is applied to gain deeper insight into the interactions at the organic-inorganic interface of the cell walls. The various organic compounds like polysaccharides as well as proteins and long-chain polyamines (LCPAs) are detected by observation of heteronuclei like 13C and 15N whereas the silica phase is studied using 29Si NMR spectroscopy. The sensitivity of the NMR experiments is strongly enhanced by isotope-labeling of the diatoms during cultivation with 13C, 15N and 29Si. The presence of two different chitin species in the biosilica is demonstrated. This observation is supported by a monosaccharide analysis of the silica-associated organic matrix where a high amount of glucosamine is found. Moreover, the Rotational Echo Double Resonance (REDOR) experiment provides distance information for heteronuclear spins. 13C{29Si} REDOR experiments reveal proximities between different organic compounds and the silica phase. The closest contacts between silica and organic compounds appear for different signals in the 13C-chemical shift range of 40–60 ppm, the typical range for LCPAs.

scholarly journals Solid-state NMR spectroscopic studies of 13C,15N,29Si-enriched biosilica from the marine diatom Cyclotella cryptica

2020 ◽  
Author(s):  
Felicitas Kolbe ◽  
Helena Leona Ehren ◽  
Simon Kohrs ◽  
Daniel Butscher ◽  
Lukas Reiß ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Organic Compounds ◽  
Solid State Nmr ◽  
Cell Walls ◽  
Organic Matrix ◽  
Marine Diatom ◽  
Distance Information ◽  
Silica Phase ◽  
Cyclotella Cryptica

Abstract Diatoms are algae producing micro- and nano-structured cell walls mainly containing amorphous silica. The shape and patterning of these cell walls is species-specific. Herein, the biosilica of Cyclotella cryptica, a centric marine diatom with a massive organic matrix, is studied. Solid-state NMR spectroscopy is applied to gain deeper insight into the interactions at the organic-inorganic interface of the cell walls. The various organic compounds like polysaccharides as well as proteins and long-chain polyamines (LCPAs) are detected by observation of heteronuclei like 13C and 15N whereas the silica phase is studied using 29Si NMR spectroscopy. The sensitivity of the NMR experiments is strongly enhanced by isotope-labeling of the diatoms during cultivation with 13C, 15N and 29Si. The presence of two different chitin species in the biosilica is demonstrated. This observation is supported by a monosaccharide analysis of the silica-associated organic matrix where a high amount of glucosamine is found. Moreover, the Rotational Echo Double Resonance (REDOR) experiment provides distance information for heteronuclear spins. 13C{29Si} REDOR experiments reveal proximities between different organic compounds and the silica phase. The closest contacts between silica and organic compounds appear for different signals in the 13C-chemical shift range of 40 – 60 ppm, the typical range for LCPAs.

scholarly journals Xylan Structure and Dynamics in Native Brachypodium Grass Cell Walls Investigated by Solid-State NMR Spectroscopy

ACS Omega ◽  
2021 ◽  
Author(s):  
Pu Duan ◽  
Samuel J. Kaser ◽  
Jan J. Lyczakowski ◽  
Pyae Phyo ◽  
Theodora Tryfona ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Cell Walls ◽  
Solid State Nmr Spectroscopy ◽  
Structure And Dynamics

scholarly journals A New Methodological Approach to Correlate Protective and Microscopic Properties by Soft X-ray Microscopy and Solid State NMR Spectroscopy: The Case of Cusa’s Stone

2021 ◽  
Vol 11 (13) ◽  
pp. 5767
Author(s):  
Veronica Ciaramitaro ◽  
Alberto Spinella ◽  
Francesco Armetta ◽  
Roberto Scaffaro ◽  
Emmanuel Fortunato Gulino ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Methodological Approach ◽  
Polymer Chains ◽  
General Question ◽  
Protective Agent ◽  
Vapour Permeability ◽  
X Ray ◽  
Solid State Nmr Spectroscopy

Hydrophobic treatment is one of the most important interventions usually carried out for the conservation of stone artefacts and monuments. The study here reported aims to answer a general question about how two polymers confer different protective performance. Two fluorinated-based polymer formulates applied on samples of Cusa’s stone confer a different level of water repellence and water vapour permeability. The observed protection action is here explained on the basis of chemico-physical interactions. The distribution of the polymer in the pore network was investigated using scanning electron microscopy and X-ray microscopy. The interactions between the stone substrate and the protective agents were investigated by means of solid state NMR spectroscopy. The ss-NMR findings reveal no significant changes in the chemical neighbourhood of the observed nuclei of each protective agent when applied onto the stone surface and provide information on the changes in the organization and dynamics of the studied systems, as well as on the mobility of polymer chains. This allowed us to explain the different macroscopic behaviours provided by each protective agent to the stone substrate.

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