Laccase catalyzed covalent coupling of fluorophenols increases lignocellulose surface hydrophobicity.
This work presents for the first time the mechanistic evidence of a laccase-catalyzed method of covalently grafting hydrophobicity enhancing fluorophenols onto Fagus sylvatica veneers. Coupling of fluorophenols onto complex lignin model compounds guaiacylglycerol beta-guaiacyl ether and syringylglycerol beta-guaiacyl ether was demonstrated by LC-MS and NMR. Laccase-mediated coupling increased binding of 4-[4-(trifluoromethyl)phenoxy]phenol (4,4-F3MPP) and 4-(trifluoromethoxy)phenol (4-F3MP) to veneers by 77.1% and 39.2%, respectively. XPS studies showed that laccase-catalyzed grafting of fluorophenols resulted in a fluorine content of 6.39% for 4,4-F3MPP, 3.01% for 4-F3MP and 0.26% for 4-fluoro-2-methylphenol (4,2-FMP). Grafting of the fluorophenols 4,2-FMP, 4-F3MP and 4,4-F3MPP led to a 9.6%, 28.6% and 65.5% increase in hydrophobicity, respectively, when compared to treatments with the respective fluorophenols in the absence of laccase, in good agreement with XPS data.
Kudanga
Tukayi
T
Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, A-8010 Graz, Austria.
Prasetyo
Endry Nugroho
EN
Widsten
Petri
P
Kandelbauer
Andreas
A
Jury
Sandra
S
Heathcote
Carol
C
Sipilä
Jussi
J
Weber
Hansjoerg
H
Nyanhongo
Gibson S
GS
Guebitz
Georg M
GM
D002851:Chromatography, High Pressure Liquid; D029964:Fagus / Q000737:chemistry*; D006140:Guaifenesin / Q000031:analogs & derivatives* / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D042845:Laccase / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D010636:Phenols / Q000378:metabolism*; D056951:Photoelectron Spectroscopy; D013499:Surface Properties; D014934:Wood / Q000378:metabolism*
D010636:Phenols; C036909:lignocellulose; D006140:Guaifenesin; C046052:guaiacylglycerol-beta-guaiacyl ether; D008031:Lignin; D042845:Laccase