scholarly journals Saccharide Analysis of Onion Outer Epidermal Walls

2021 ◽  
Author(s):  
Liza A. Wilson ◽  
Fabien Deligey ◽  
Tuo Wang ◽  
Daniel J. Cosgrove
Keyword(s):  
High Performance ◽  
Amperometric Detection ◽  
Dry Weight ◽  
Anion Exchange Chromatography ◽  
Enzymatic Digestion ◽  
Exchange Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
High Yield ◽  
Neutral Sugars ◽  
Acidic Methanolysis

AbstractBackgroundEpidermal cell walls have special structural and biological roles in the life of the plant. Typically they are multi-ply structures encrusted with waxes and cutin which protect the plant from dehydration and pathogen attack. These characteristics may also reduce chemical and enzymatic deconstruction of the wall for sugar analysis and conversion to biofuels. We have assessed the saccharide composition of the outer epidermal wall of onion scales with different analytical methods. This wall is a particularly useful model for cell wall imaging and mechanics.ResultsEpidermal walls were depolymerized by acidic methanolysis combined with 2 M trifluoracetic acid hydrolysis and the resultant sugars were analyzed by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Total sugar yields based on wall dry weight were low (53%). Removal of waxes with chloroform increased the sugar yields to 73% and enzymatic digestion did not improve these yields. Analysis by gas chromatography/mass spectrometry (GC/MS) of per-O-trimethylsilyl (TMS) derivatives of the sugar methyl glycosides produced by acidic methanolysis gave a high yield for galacturonic acid (GalA) but glucose (Glc) was severely reduced. In a complementary fashion, GC/MS analysis of methyl alditols produced by permethylation gave substantial yields for glucose and other neutral sugars, but GalA was severely reduced. Analysis of the walls by 13C solid-state NMR confirmed and extended these results and revealed 15% lipid content after chloroform extraction (potentially cutin and unextractable waxes).ConclusionsAlthough exact values vary with the analytical method, our best estimate is that polysaccharide in the outer epidermal wall of onion scales is comprised of homogalacturonan (~50%), cellulose (~20%), galactan (~10%), xyloglucan (~10%) and smaller amounts of other polysaccharides. Low yields of specific monosaccharides by some methods may be exaggerated in epidermal walls impregnated with waxes and cutin and call for cautious interpretation of the results.

scholarly journals Saccharide analysis of onion outer epidermal walls

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Liza A. Wilson ◽  
Fabien Deligey ◽  
Tuo Wang ◽  
Daniel J. Cosgrove
Keyword(s):  
High Performance ◽  
Amperometric Detection ◽  
Dry Weight ◽  
Anion Exchange Chromatography ◽  
Enzymatic Digestion ◽  
Exchange Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
High Yield ◽  
Neutral Sugars ◽  
Acidic Methanolysis

Abstract Background Epidermal cell walls have special structural and biological roles in the life of the plant. Typically they are multi-ply structures encrusted with waxes and cutin which protect the plant from dehydration and pathogen attack. These characteristics may also reduce chemical and enzymatic deconstruction of the wall for sugar analysis and conversion to biofuels. We have assessed the saccharide composition of the outer epidermal wall of onion scales with different analytical methods. This wall is a particularly useful model for cell wall imaging and mechanics. Results Epidermal walls were depolymerized by acidic methanolysis combined with 2M trifluoracetic acid hydrolysis and the resultant sugars were analyzed by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Total sugar yields based on wall dry weight were low (53%). Removal of waxes with chloroform increased the sugar yields to 73% and enzymatic digestion did not improve these yields. Analysis by gas chromatography/mass spectrometry (GC/MS) of per-O-trimethylsilyl (TMS) derivatives of the sugar methyl glycosides produced by acidic methanolysis gave a high yield for galacturonic acid (GalA) but glucose (Glc) was severely reduced. In a complementary fashion, GC/MS analysis of methyl alditols produced by permethylation gave substantial yields for glucose and other neutral sugars, but GalA was severely reduced. Analysis of the walls by 13C solid-state NMR confirmed and extended these results and revealed 15% lipid content after chloroform extraction (potentially cutin and unextractable waxes). Conclusions Although exact values vary with the analytical method, our best estimate is that polysaccharide in the outer epidermal wall of onion scales is comprised of homogalacturonan (~ 50%), cellulose (~ 20%), galactan (~ 10%), xyloglucan (~ 10%) and smaller amounts of other polysaccharides. Low yields of specific monosaccharides by some methods may be exaggerated in epidermal walls impregnated with waxes and cutin and call for cautious interpretation of the results.

scholarly journals Quantitative Analysis of Fructo-oligosaccharides in Gynura divaricata subsp. formosana by High Performance Anion Exchange Chromatography-Pulsed Amperometric Detection

2012 ◽  
Vol 7 (8) ◽  
pp. 1934578X1200700
Author(s):  
Shen-Chieh Chou ◽  
Shoei-Sheng Lee
Keyword(s):  
Quantitative Analysis ◽  
Anion Exchange ◽  
High Performance ◽  
Amperometric Detection ◽  
Dry Weight ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Fresh Weight ◽  
Pulsed Amperometric Detection ◽  
Limit Of Quantitation

High performance anion exchange chromatography-pulsed amperometric detection was employed in this study to conduct quantitative analysis of the inulin-related fructo-oligosaccharides present in Gynura divaricata subsp. formosana. Result obtained for the 1-kestose (GF2), nystose (GF3) and 1F-β-fructofuranosyl-nystose (GF4) contents were 146.60 ± 0.04, 24.70 ± 0.75 and 16.60 ± 0.91 μg/g, fresh weight, and 68.90 ± 0.02, 7.60 ± 1.34 and 149.30 ± 0.06 μg/g (mean ± RSD), dry weight, respectively. Using this method, the limit of quantitation was 20 μg/mL and the linear detectability between 0-250 μg/mL. The developed method provides a practical analysis for these low caloric value, prebiotic and non-digestible carbohydrates in the genus Gynura.

scholarly journals Enzymatic Synthesis and Characterization of Different Families of Chitooligosaccharides and Their Bioactive Properties

2021 ◽  
Vol 11 (7) ◽  
pp. 3212
Author(s):  
Noa Miguez ◽  
Peter Kidibule ◽  
Paloma Santos-Moriano ◽  
Antonio O. Ballesteros ◽  
Maria Fernandez-Lobato ◽  
...  
Keyword(s):  
High Performance ◽  
Chemical Characterization ◽  
Amperometric Detection ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Enzymatic Production ◽  
Bioactive Properties ◽  
Substrate Properties ◽  
Chitin Hydrolysis

Chitooligosaccharides (COS) are homo- or hetero-oligomers of D-glucosamine (GlcN) and N-acetyl-D-glucosamine (GlcNAc) that can be obtained by chitosan or chitin hydrolysis. Their enzymatic production is preferred over other methodologies (physical, chemical, etc.) due to the mild conditions required, the fewer amounts of waste and its efficiency to control product composition. By properly selecting the enzyme (chitinase, chitosanase or nonspecific enzymes) and the substrate properties (degree of deacetylation, molecular weight, etc.), it is possible to direct the synthesis towards any of the three COS types: fully acetylated (faCOS), partially acetylated (paCOS) and fully deacetylated (fdCOS). In this article, we review the main strategies to steer the COS production towards a specific group. The chemical characterization of COS by advanced techniques, e.g., high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and MALDI-TOF mass spectrometry, is critical for structure–function studies. The scaling of processes to synthesize specific COS mixtures is difficult due to the low solubility of chitin/chitosan, the heterogeneity of the reaction mixtures, and high amounts of salts. Enzyme immobilization can help to minimize such hurdles. The main bioactive properties of COS are herein reviewed. Finally, the anti-inflammatory activity of three COS mixtures was assayed in murine macrophages after stimulation with lipopolysaccharides.

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