Determination of bonding patterns of carbon-13 specifically enriched dehydrogenatively polymerized lignin in solution and solid state

Lewis, Norman; Newman, James M.; Just, George; Ripmeister, J.

doi:10.1021/ma00174a006

Cited by 62 publications

(43 citation statements)

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“…Moreover, the resistance of most aromatic groups to chemical depolymerization treatments supports a prior hypothesis that these functionalities are located primarily within the cell wall (6). In contrast to these results for suberin, cutin from limes is found to be predominantly an aliphatic polyester (18,22), and lignins have been described as complex phenylpropanoid networks (10)(11)(12).…”

Section: Discussionsupporting

confidence: 73%

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¹³C Nuclear Magnetic Resonance Study of Suberized Potato Cell Wall

Garbow¹,

Ferrantello²,

Stark³

1989

Plant Physiol.

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High-resolution, solid-state 13C nuclear magnetic resonance (NMR) spectra are reported for suberized cell wall from potatoes (Solanum tuberosum L.). Through experiments combining the techniques of cross polarization and magic-angle spinning, we verified that suberin, like cutin, is a polyester and demonstrated that it also has phenylpropanoid groups characteristic of lignin. Roughly 50% of the suberized material consists of cell-wall polymers; aromatics and other unsaturated linkages outnumber methylene groups 2:1. In conjunction with traditional direct-polarization NMR results, these experiments provide support for prior suggestions that suberin and cell-wall components are chemically bonded via aromatic groups.Suberin and cutin are biopolymers with important protective functions in higher plants, serving as barriers against moisture loss for underground and aerial organs, respectively. For example, the formation of suberin within cell walls helps to prevent moisture loss and decay in potatoes, while the cuticular layer of fruits mitigates the effects of evaporation, wind, and fungal pathogens. Suberization also occurs as a defensive response, with polymer deposition occurring for approximately 1 week following wounding of the tissue. The ultrastructure, biosynthesis, and chemical identification of these materials have been the subject of much study during the past 20 years, with the goal of developing a molecular rationale for their physiological functions (5, 6).Spectroscopic analysis of intact cutin and suberin has been limited by their insolubility, and because the suberized cell wall forms an inseparable and chemically complex unit. Instead, research in this area has focused on characterization of the soluble, monomeric products of chemical depolymerization treatments. Using primarily GC-MS, both materials have been identified as polyesters. An incomplete picture of biopolymer structure emerges from such studies, however, since much of the plant material is resistant to degradation and the identification of monomeric constituents alone provides little clue as to how the units are linked together in living plants.A new spectroscopic approach to plant polyester structure ' (22). In the latter case, it was possible to determine the identity, number, and motional characteristics of the major carbon types and to develop a working model of cutin as a flexible netting with some cross-link constraints.In the current work, we present high-resolution naturalabundance '3C NMR results for suberized cell-wall tissue from wound-healing potatoes (18). CPMAS is employed to identify major chemical functionalities of both the suberin and cellwall components and to estimate the relative numbers of each carbon type present. These results allow compositional comparisons to be made with cutin, lignin, and the soluble depolymerization products of suberized potato tissue. In conjunction with traditional DPMAS, the CPMAS spectra are examined in light of proposed models for the attachment of suberin and polysaccharide co...

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Section: Discussionsupporting

confidence: 73%

“…Solution-state NMR and other physical evidence (7)(8)(9) (10,11,18,22); it also suggests that the aromatic domains of all three materials originate from deamination of L-phenylalanine (6, 1 1).…”

Section: Discussionmentioning

confidence: 93%

¹³C Nuclear Magnetic Resonance Study of Suberized Potato Cell Wall

Garbow¹,

Ferrantello²,

Stark³

1989

Plant Physiol.

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“…Dehydrogenatively polymerized (DHP) lignin was prepared from coniferyl alcohol as described (8). To After incubation periods of0, 24, and 96 hr, two 10-Al aliquots were taken and diluted with 990 Al of acetate buffer for enzyme assay (8).…”

Section: Methodsmentioning

confidence: 99%

“…Dehydrogenatively polymerized (DHP) lignin was prepared from coniferyl alcohol as described (8). To obtain uniformly high molecular weight fractions of dioxane-soluble material, 300-pl aliquots of DHP lignin (12.5 mg/ml of dimethylformamide) were passed through the Sephadex LH-20 column with anhydrous dioxane as the eluant.…”

Section: Introductionmentioning

confidence: 99%

Lignin degradation by peroxidase in organic media: A reassessment

Lewis¹,

Razal²,

Yamamoto³

1987

Proc. Natl. Acad. Sci. U.S.A.

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The effect of horseradish peroxidase/H202 in organic medium (dioxane/aqueous buffer, pH 5, 95:5) on the depolymerization of synthetic (dehydrogenatively polymerized) lignin was reinvestigated. In contrast to previous claims [Dordick, J. S., Marietta, M. A. & Klibanov, A. M. (1986) Proc. Natl. Acad. Sci. USA 83, 6255-6257], our results demonstrated that vigorous depolymerization of this substrate did not occur. Further, during this treatment ferulic acid was not a significant biodegradation product.It is well-established that certain fungi are capable of biodegrading structural polymers in plant material. Of particular interest are the white-rot fungi, such as Phanerochaete chrysosporium (1, 2), which can, to some extent, degrade lignin. Much effort has been expended towards understanding these biochemical conversions at the molecular level (3). In 1983, an enzyme (ligninase) isolated from P. chrysosporium was described as having powerful lignin-degrading capabilities (4). The substrate used for biodegradation in this study was not lignin per se, but instead an aqueous acetone extract of spruce wood, which had been methylated with 14CH31. More detailed investigations revealed that these ligninases were, in fact, peroxidase isoenzymes and, as such, did not vigorously degrade lignin. Indeed, it has now been reported that ligninase treatment of nonmethylated lignin results in both polymerization and depolymerization of the phenolic material (5). This is in general agreement with previous studies using horseradish peroxidase in aqueous media, from which it was concluded that although internal rearrangement of the lignin substrate can occur, the net effect was not that of lignin depolymerization (6). Thus, the report (7) that horseradish peroxidase/H202 in organic medium (dioxane/10 mM acetate buffer, pH 5, 95:5) could vigorously depolymerize both synthetic and natural lignin was so surprising as to warrant independent verification. MATERIALS AND METHODS Gel-Filtration Chromatography. A low-pressure liquid chromatography system was employed that used Sephadex LH-20 packed in an SR 10/50 column (Pharmacia). The Sephadex gel was swollen in the liquid phase for 3 hr before packing and then was equilibrated with six column volumes. Each column was calibrated with polystyrenes of molecular weight 2000, 800 (Pressure Chemical, Pittsburgh), and 1000 (Polymer Laboratory, Church Stretton, England) and dibenzyl malonate (molecular weight 284; Aldrich). The eluant was monitored at 280 nm, using an LKB Bromma 2158 Uvicord SD detector. Elution was either with eluant A (0.1 M LiCl in redistilled N,N-dimethylformamide) or eluant B (anhydrous dioxane).Purification of Dioxane. A mixture of dioxane (3 liters) plus concentrated HCl (37.5 ml) in water (300 ml) was refluxed for 12-18 hr under N2. The solution was cooled to room temperature and excess solid KOH was added with stirring. The dioxane was decanted from the thick, dark aqueous layer that resulted and was stored over KOH (150 g of KOH per liter of dioxane). The dioxane...

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“…In a theoretical model of lignin synthesis, Jurasek (1995) predicted an irregular shape of lignin macromolecules growing freely without interference from the other molecules (hemicellulose and cellulose), and spherical shape in the proximity of cellulose or hemicellulose layers. Since naturally occurring lignin cannot be isolated in unaltered form, enzymatically polymerized dehydrogenate polymer (DHP) of coniferyl alcohol, obtained in vitro, is used as the best model compound for the purpose of structural studies of lignin (Lewis et al 1988). Using scanning tunneling microscopy (STM) images of DHP, combined with gel permeation chromatography (GPC) measurements (Radotic et al 1994), it was shown that lignin has a well-ordered structural organization with fractal dimensionality, even if it is synthesized in vitro.…”

Section: Introductionmentioning

confidence: 99%

Visualization of artificial lignin supramolecular structures

et al. 2000

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Summary:In this paper we are presenting the results of our environmental scanning electron microscopy (ESEM) investigation of the lignin model compound-enzymatically polymerized coniferyl alcohol, also known as dehydrogenate polymer (DHP). The goals of this study were to visualize the supramolecular organization of DHP polymer on various substrates, namely graphite, mica, and glass, and to explore the influence of substrate surface properties and associated collective phenomena on the lignin self-assembled supramolecular structure. Based on results obtained with ESEM, combined with previously published results based on scanning tunneling microscopy (STM) and electron spin resonance (ESR) technique, we looked at lignin structure ranging from a monomer on a fraction of nanometer scale to a large aggregate on a fraction of millimeter scale, therefore using six orders of magnitude range of size. Herein, we are presenting evidence that there are at least four different levels of the supramolecular structure of lignin, and that its supramolecular organization is well dependent on the substrate surface characteristics, such as hydrophobicity, delocalized orbitals, and surface-free energy.

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Determination of bonding patterns of carbon-13 specifically enriched dehydrogenatively polymerized lignin in solution and solid state

Cited by 62 publications

References 3 publications

¹³C Nuclear Magnetic Resonance Study of Suberized Potato Cell Wall

¹³C Nuclear Magnetic Resonance Study of Suberized Potato Cell Wall

Lignin degradation by peroxidase in organic media: A reassessment

Visualization of artificial lignin supramolecular structures

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Determination of bonding patterns of carbon-13 specifically enriched dehydrogenatively polymerized lignin in solution and solid state

Cited by 62 publications

References 3 publications

13C Nuclear Magnetic Resonance Study of Suberized Potato Cell Wall

13C Nuclear Magnetic Resonance Study of Suberized Potato Cell Wall

Lignin degradation by peroxidase in organic media: A reassessment

Visualization of artificial lignin supramolecular structures

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Product

Resources

About

¹³C Nuclear Magnetic Resonance Study of Suberized Potato Cell Wall

¹³C Nuclear Magnetic Resonance Study of Suberized Potato Cell Wall