Comparative Studies on Dehydrogenative Polymerization of Coniferyl Alcohol by Laccases and Peroxidases. Part 1. Preliminary Results

Abstract Dehydrogenative polymerization of isoconiferin (IC; coniferyl alcohol γ-O-β-D-glucopyranoside) catalyzed by horseradish peroxidase (HRP) was carried out. The polymerization of IC proceeded in a homogeneous system, resulting in a water-soluble dehydrogenation polymer (IC-DHP). The degree of polymerization (DP) of IC-DHP was significantly higher than that of a standard dehydrogenative polymer (CA-DHP) obtained from coniferyl alcohol (CA) in a heterogeneous system. Under optimum conditions, the DP of IC-DHP was 44 (M n=1.5×104), whereas that for CA-DHP was only 11 (M n=3.0×103, as acetate). Spectroscopic analyses confirmed that IC-DHP has a lignin-like structure containing D-glucose moieties attached to the lignin side-chains. The D-glucose unit introduced into γ-O position of CA essentially influenced the water solubility and molecular mass of the resulting DHP.

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Generation of lignin polymer models via dehydrogenative polymerization of coniferyl alcohol and syringyl alcohol via several plant peroxidases involved in lignification and analysis of the resulting DHPs by MALDI-TOF analysis

Holzforschung ◽

10.1515/hf-2017-0125 ◽

2018 ◽

Vol 72 (4) ◽

pp. 267-274 ◽

Cited By ~ 3

Author(s):

Jun Shigeto ◽

Hiroki Honjo ◽

Koki Fujita ◽

Yuji Tsutsumi

Keyword(s):

Cell Wall ◽

Horseradish Peroxidase ◽

Molecular Size ◽

Coniferyl Alcohol ◽

Populus Alba ◽

Polymer Formation ◽

Polymer Models ◽

Plant Peroxidases ◽

Molecular Size Distribution ◽

Dehydrogenative Polymerization

AbstractThe mechanism of lignin dehydrogenative polymerization (DHP), made by means of horseradish peroxidase (HRP), was studied in comparison with other plant peroxidases. Interestingly, HRP is efficient for guaiacyl type polymer formation (G-DHPs), but is not efficient in the case of syringyl type DHPs (S-DHPs). It was previously demonstrated that lignification-relatedArabidopsisthalianaperoxidases, AtPrx2, AtPrx25 and AtPrx71, and cationic cell-wall-bound peroxidase (CWPO-C) fromPopulus albaare successful to oxidize syringyl- and guaiacyl-type monomers and larger lignin-like molecules. This is the reason why in the present study the DHP formation by means of these recombinant peroxidases was tested, and all these enzymes were successful for formation of both G-DHP and S-DHP in acceptable yields. CWPO-C led to S-DHP molecular size distribution similar to that of isolated lignins.

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Radical transfer system in the enzymatic dehydrogenative polymerization (DHP formation) of coniferyl alcohol (CA) and three dilignols

Holzforschung ◽

10.1515/hf-2018-0044 ◽

2019 ◽

Vol 73 (2) ◽

pp. 189-195 ◽

Cited By ~ 2

Author(s):

Yasuyuki Matsushita ◽

Masaya Okayama ◽

Dan Aoki ◽

Sachie Yagami ◽

Kazuhiko Fukushima

Keyword(s):

Molecular Weight ◽

Reaction Kinetics ◽

Consumption Rate ◽

Coniferyl Alcohol ◽

Clear Picture ◽

Transfer System ◽

Radical Transfer ◽

Dehydrodiconiferyl Alcohol ◽

Dehydrogenative Polymerization

Abstract No clear picture has yet been elaborated concerning the mechanism of lignin growth, and thus this topic is the focus of the present paper. Namely, the enzymatic dehydrogenative polymerization (DHP formation) of coniferyl alcohol (CA, as a monolignol) and three dilignols and their reaction kinetics were investigated. The dilignols [guaiacylglycerol-β-coniferyl ether (IβO4), dehydrodiconiferyl alcohol (IIβ5), and pinoresinol (IIIββ)] and CA as a monolignol [(3-OCD3)-coniferyl alcohol (CAOCD3)] were synthesized and subjected to enzymatic DHP formation. The dilignol derived from CAOCD3 could be identified by its higher molecular weight in comparison with the starting dilignols (IβO4, IIβ5, and IIIββ). Based on the observed consumption rate of the CA and its dilignols, it was proposed that a radical transfer system exists between the dilignols, which is generated from the CA and the starting substrates.

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Dehydrogenative Polymerization of Coniferyl Alcohol in Artificial Polysaccharides Matrices: Effects of Xylan on the Polymerization

Journal of Agricultural and Food Chemistry ◽

10.1021/acs.jafc.5b01070 ◽

2015 ◽

Vol 63 (18) ◽

pp. 4613-4620 ◽

Cited By ~ 18

Author(s):

Qiang Li ◽

Keiichi Koda ◽

Arata Yoshinaga ◽

Keiji Takabe ◽

Masatsugu Shimomura ◽

...

Keyword(s):

Coniferyl Alcohol ◽

Dehydrogenative Polymerization

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Diversity of the olfactory sensilla in caddisflies (Trichoptera)

Zoosymposia ◽

10.11646/zoosymposia.10.1.20 ◽

2016 ◽

Vol 10 (1) ◽

pp. 224-233 ◽

Cited By ~ 8

Author(s):

VLADIMIR D. IVANOV ◽

STANISLAV I. MELNITSKY

Keyword(s):

Comparative Study ◽

Comparative Studies ◽

Olfactory Sensilla ◽

Preliminary Results ◽

Antennal Flagellum ◽

Structural Types ◽

Sensory Structures ◽

Rich Material

Antennal segments in Trichoptera are provided with various sensilla showing the maximal diversity on the antennal flagellum. Comparative studies of cuticle parts of sensilla provide rich material on various sensory structures. Preliminary results of a comparative study of the antennal surface in 28 families of Trichoptera reveal more than 17 structural types of the cuticular microstructures. Some of them (microtrichia, scales, and 2 specialized types of trichia) are apparently not sensilla. The diversity of sensory structures is illustrated and discussed in connection with taxonomy and evolution.

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Monolignol dehydrogenative polymerization in vitro in the presence of dioxane and a methylated β-β′ dimer model compound

Holzforschung ◽

10.1515/hf.2008.099 ◽

2008 ◽

Vol 62 (5) ◽

Cited By ~ 1

Author(s):

Anders Holmgren ◽

Liming Zhang ◽

Gunnar Henriksson

Keyword(s):

Model Compound ◽

Coniferyl Alcohol ◽

Enzymatic Oxidation ◽

High Solubility ◽

Dimer Model ◽

Homogeneous Polymerization ◽

Lignin Polymerization ◽

C Nmr ◽

Dehydrogenative Polymerization

Abstract Lignin formation is believed to occur by polymerization of resonance-stabilized monolignol radicals formed by enzymatic oxidation. Recently, different hypotheses suggested that lignin polymerization is influenced by surfaces in the cell wall which can be polysaccharides or proteins. The latter is called the proteinaceous dirigent sites/template polymerization hypothesis. According to another hypothesis, lignin itself is believed to act as a template and replicate its primary structure. In this work, dehydrogenative polymerization (DHP) of the lignin precursor coniferyl alcohol was performed in vitro in the presence and absence of pinoresinol dimethyl ether (a β-β′ dimer model). Another peculiarity of the experiments was the presence of dioxane which afforded a high solubility of the reactants. The question was whether the presence of β-β′ dimer model would change the structure of the DHP formed. The DHPs were analyzed by quantitative 13C NMR, GC-FID, and GC-MS. The dimer model as a template in the homogeneous polymerization state (in solution) did not influence the DHP structure.

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Effects of a Biologically Relevant Antioxidant on the Dehydrogenative Polymerization of Coniferyl Alcohol

Biomacromolecules ◽

10.1021/bm800704k ◽

2008 ◽

Vol 9 (12) ◽

pp. 3378-3382 ◽

Cited By ~ 3

Author(s):

Anders Holmgren ◽

Gunnar Henriksson ◽

Liming Zhang

Keyword(s):

Coniferyl Alcohol ◽

Biologically Relevant ◽

Dehydrogenative Polymerization

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The O–C diagrams of minor planets − a new approach to modelling the rotation

International Astronomical Union Colloquium ◽

10.1017/s0252921100031407 ◽

1999 ◽

Vol 173 ◽

pp. 185-188

Author(s):

Gy. Szabó ◽

K. Sárneczky ◽

L.L. Kiss

Keyword(s):

Error Analysis ◽

Time Dependence ◽

Theoretical Work ◽

Minor Planet ◽

Minor Planets ◽

New Approach ◽

Preliminary Results ◽

Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

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Cyclic Evolution of Sunspots: Gleaning New Results from Old Data

International Astronomical Union Colloquium ◽

10.1017/s0252921100064411 ◽

2000 ◽

Vol 179 ◽

pp. 163-165

Author(s):

S. K. Solanki ◽

M. Fligge ◽

P. Pulkkinen ◽

P. Hoyng

Keyword(s):

Sunspot Number ◽

Sunspot Cycle ◽

Preliminary Results ◽

Butterfly Diagram

AbstractThe records of sunspot number, sunspot areas and sunspot locations gathered over the centuries by various observatories are reanalysed with the aim of finding as yet undiscovered connections between the different parameters of the sunspot cycle and the butterfly diagram. Preliminary results of such interrelationships are presented.

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