| Abstrakt: |
A β-β′ linked lignin model compound, d,l-syringaresinol monobenzyl ether (Ib) was incubated with Fusarium solani M-13-1 in a shaking culture. From the culture filtrates, three compounds II, IIIb and IV were isolated and identified. Substrate Ib was oxidized at the α-position of the side chain to give a hemiketal, an α-hydroxylated compound IIA, which was then transformed to the ketoalcohol, 3-hydroxymethyl-2-(4-benzyloxy-3,5-dimethoxyphenyl)-4-(4-hydroxy-3,5-dimethoxybenzoyl)-tetrahydrofuran (IIB). These products were converted to a γ-lactone derivative, 6-oxo-2-(4-benzyloxy-3,5-dimethoxyphenyl)-3,7-dioxabicyclo-[3,3,0]-octane (IIIb), via alkyl-aryl cleavage. The syringyl moiety released from II by the cleavage reaction was identified as 2,6-dimethoxy- p-benzoquinone (IV). Incubation of 2,6-dimethoxyphenol (V) in fungal culures did not give the p-quinone IV. d,l-Syringaresinol dimethyl ether was not degraded and the etherated moiety of Ib was not attacked by the fungus, indicating that the degradation of d,l-syringaresinol was catalyzed by phenol oxidizing enzymes. The oxidation products of Ib with peroxidase/HO was investigated and discussed in relation to the degradation products of the fungus. [ABSTRACT FROM AUTHOR] |
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