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Polymerization of coniferyl alcohol by Mn 3+ ‐mediated (enzymatic) oxidation: Effects of H 2 O 2 concentration, aqueous organic solvents, and pH
Author(s) -
TaboadaPuig Roberto,
LúChau Thelmo A.,
Moreira María T.,
Feijoo Gumersindo,
Lema Juan M.,
Fagerstedt Kurt,
OhraAho Taina,
Liitiä Tiina,
Heikkinen Harri,
Ropponen Jarmo,
Tamminen Tarja
Publication year - 2017
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1002/btpr.2562
Subject(s) - dhps , chemistry , polymerization , hydrogen peroxide , aqueous solution , coniferyl alcohol , monomer , lignin , nuclear chemistry , organic chemistry , polymer , inorganic chemistry , polymer chemistry , plasmodium falciparum , malaria , immunology , biology
The objective of this study was to evaluate the ability of one versatile peroxidase and the biocatalytically generated complex Mn(III)‐malonate to polymerize coniferyl alcohol (CA) to obtain dehydrogenation polymers (DHPs) and to characterize how closely the structures of the formed DHPs resemble native lignin. Hydrogen peroxide was used as oxidant and Mn 2+ as mediator. Based on the yields of the polymerized product, it was concluded that the enzymatic reaction should be performed in aqueous solution without organic solvents at 4.5 ≤ pH ≤ 6.0 and with 0.75 ≤ H 2 O 2 :CA ratio ≤ 1. The results obtained from the Mn 3+ ‐malonate‐mediated polymerization showed that the yield was almost 100%. Reaction conditions had, however, effect on the structures of the formed DHPs, as detected by size exclusion chromatography and pyrolysis‐GC/MS. It can be concluded that from the structural point of view, the optimal pH for DHP formation using the presently studied system was 3 or 4.5. Low H 2 O 2 /CA ratio was beneficial to avoid oxidative side reactions. However, the high frequency of β–β linkages in all cases points to dimer formation between monomeric CA rather than endwise polymerization. © 2017 American Institute of Chemical Engineers Biotechnol. Prog. , 34:81–90, 2018