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

Holzforschung ◽  
2019 ◽  
Vol 73 (2) ◽  
pp. 189-195 ◽  
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.

scholarly journals Dependence of reaction kinetics on molecular weight in hydrodenitrogenation of shale oil.

1995 ◽  
Vol 28 (1) ◽  
pp. 122-124
Author(s):  
Soon-Yong Jeong ◽  
James W. Bunger ◽  
Jeong-Kwon Suh ◽  
Jung-Min Lee
Keyword(s):  
Molecular Weight ◽  
Reaction Kinetics ◽  
Shale Oil

Studies on the dehydrogenative polymerizations of monolignol β-glycosides. Part 2: Horseradish peroxidase-catalyzed dehydrogenative polymerization of isoconiferin

Holzforschung ◽  
2006 ◽  
Vol 60 (5) ◽  
pp. 513-518 ◽  
Author(s):  
Yuki Tobimatsu ◽  
Toshiyuki Takano ◽  
Hiroshi Kamitakahara ◽  
Fumiaki Nakatsubo
Keyword(s):  
Horseradish Peroxidase ◽  
Water Solubility ◽  
Homogeneous System ◽  
Degree Of Polymerization ◽  
Coniferyl Alcohol ◽  
Water Soluble ◽  
Optimum Conditions ◽  
Spectroscopic Analyses ◽  
Dehydrogenation Polymer ◽  
Dehydrogenative Polymerization

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.

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 ◽  
2018 ◽  
Vol 72 (4) ◽  
pp. 267-274 ◽  
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.

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

2015 ◽  
Vol 63 (18) ◽  
pp. 4613-4620 ◽  
Author(s):  
Qiang Li ◽  
Keiichi Koda ◽  
Arata Yoshinaga ◽  
Keiji Takabe ◽  
Masatsugu Shimomura ◽  
...  
Keyword(s):  
Coniferyl Alcohol ◽  
Dehydrogenative Polymerization

The influence of molecular weight and chemical structure of soft segment in reaction kinetics with tolyl isocyanate

2001 ◽  
Vol 37 (8) ◽  
pp. 1685-1693 ◽  
Author(s):  
A Eceiza ◽  
K de la Caba ◽  
V Gascón ◽  
M.A Corcuera ◽  
I Mondragon
Keyword(s):  
Molecular Weight ◽  
Reaction Kinetics ◽  
Chemical Structure ◽  
Soft Segment
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