A number of model compounds resembling the fundamental bonding patterns of residual kraft lignin, including a series of stilbenes, were incubated with laccase from Trametes versicolor in the presence and absence of delignification `mediators' ABTS and HBT. The condensed kraft lignin model compounds seem to undergo initial degradation by laccase mainly via benzylic oxidation, demethylation and hydroxylation reactions. Phenolic 5-5', diphenylmethane and alpha-5 lignin models were found to be degraded mainly via side-chain oxidation reactions. Among the models studied, a phenolic stilbene was found to be the most reactive, yielding several products showing side-chain oxidation/transposition, demethoxylation and hydroxylation reactions. Non-phenolic 5-5', diphenylmethane and stilbene model compounds were found unreactive even in the presence of the laccase-mediator system. (C) 1998 Elsevier Science Ltd. All rights reserved.
Crestini, C., Argyropoulos, D. (1998). The early oxidative biodegradation steps of residual kraft lignin models with laccase. BIOORGANIC & MEDICINAL CHEMISTRY, 6(11), 2161-2169 [10.1016/S0968-0896(98)00173-4].
The early oxidative biodegradation steps of residual kraft lignin models with laccase
CRESTINI, CLAUDIA;
1998-01-01
Abstract
A number of model compounds resembling the fundamental bonding patterns of residual kraft lignin, including a series of stilbenes, were incubated with laccase from Trametes versicolor in the presence and absence of delignification `mediators' ABTS and HBT. The condensed kraft lignin model compounds seem to undergo initial degradation by laccase mainly via benzylic oxidation, demethylation and hydroxylation reactions. Phenolic 5-5', diphenylmethane and alpha-5 lignin models were found to be degraded mainly via side-chain oxidation reactions. Among the models studied, a phenolic stilbene was found to be the most reactive, yielding several products showing side-chain oxidation/transposition, demethoxylation and hydroxylation reactions. Non-phenolic 5-5', diphenylmethane and stilbene model compounds were found unreactive even in the presence of the laccase-mediator system. (C) 1998 Elsevier Science Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
