Surface-Initiated Dehydrogenative Polymerization of Monolignols: A Quartz Crystal Microbalance with Dissipation Monitoring and Atomic Force Microscopy Study

Abstract

This work highlights a real-time and label-free method to monitor the dehydrogenative polymerization of monolignols initiated by horseradish peroxidase (HRP) physically immobilized on surfaces using a quartz crystal microbalance with dissipation monitoring (QCM-D). The dehydrogenative polymer (DHP) films are expected to provide good model substrates for studying ligninolytic enzymes. The HRP was adsorbed onto gold or silica surfaces or onto and within porous desulfated nanocrystalline cellulose films from an aqueous solution. Surface-immobilized HRP retained its activity and selectivity for monolignols as coniferyl and p-coumaryl alcohol underwent dehydrogenative polymerization in the presence of hydrogen peroxide, whereas sinapyl alcohol polymerization required the addition of a nucleophile. The morphologies of the DHP layers on the surfaces were investigated via atomic force microscopy (AFM). Data from QCM-D and AFM showed that the surface-immobilized HRP-initiated dehydrogenative polymerization of monolignols was greatly affected by the support surface, monolignol concentration, hydrogen peroxide concentration, and temperature.

Radicals from the gas-phase pyrolysis of a lignin model compound: p-coumaryl alcohol

“…1) that contains the cinnamyl alcohol group, is scarce. The majority of publications focus on the biological implications of p -CMA, particularly, microbiological formation, 24 oxidizing peroxidases, 25 biodegradation by Aspergillus flavus , 26 enzymic dehydrogenation or dehydrogenative polymerization, 27 etc . It was also suggested that the primary aliphatic hydroxyl group in the allylic side chain of the coniferyl alcohol is a site of transferable hydrogen, and the terminal oxygen-centered radical is suggested to be one of the four radicals that are formed during the thermolysis of coniferyl alcohol.…”

Alcohol acyl transferase 1 links two distinct volatile pathways that produce esters and phenylpropenes in apple fruit

“…Chavicol was synthesised by BBr 3 demethylation of estragole (Agharahimi and LeBel, ), and p ‐coumaryl alcohol by esterification of p ‐coumaric acid (Wang et al ., ) followed by DIBAL reduction to p ‐coumaryl alcohol (Quideau and Ralph, ). ( Z )‐ and ( E )‐isochavicol were synthesised as described by Lin et al .…”

First Syntheses of (±)‐Butesuperins A and B

“…Our synthesis began with the preparation of isoflavone 5 , coniferyl alcohol ( 8 ), and sinapyl alcohol ( 9 ), as illustrated in Scheme . Isoflavone 5 was produced by the coupling of commercially available pyrogallol ( 3 ) and phenylacetic acid 4 as reported in the literature, and cinnamyl alcohols 8 and 9 were obtained by reduction of respective ferulic acid ( 6 ) and sinapic acid ( 7 ) according to a literature procedure . With both isoflavone 5 and coniferyl alcohol ( 8 ) in hand, their assembly was examined under a number of conditions (Scheme and Table ).…”