Metabolism of a phenylcoumaran substructure lignin model compound in ligninolytic cultures ofPhanerochaete chrysosporium

✍ Scribed by Fumiaki Nakatsubo; T. Kent Kirk; Mikio Shimada; Takayoshi Higuchi

• Publisher: Springer
• Year: 1981
• Tongue: English
• Weight: 617 KB
• Volume: 128
• Category: Article
• ISSN: 0302-8933
• DOI: 10.1007/bf00405924

✦ Synopsis

The degradation of the phenylcoumaran substructure model compound methyl dehydrodiconiferyl alcohol by the white-rot wood decay fungus Phanerochaete chrysosporium was investigated using culture conditions optimized for lignin oxidation. Initial attack was in the cinnamyl alcohol side chain, which was oxidized to a glycerol structure. This was subsequently converted by loss of the two terminal carbon atoms, C~, and C~,, to yield a C~,-aldehyde structure, which was further oxidized to the C~,-acid compound. The next detected intermediate, a phenylcoumarone, was produced by double bond formation between C~ and C~, and oxidation of the C~-alcohol to an aldehyde group. Further oxidation of C~ to an acid yielded the next intermediate. The final identified degradation product was veratric acid. No products from the 5-substituted aromatic ring, and no phenolic products, were found. The initial glycerol-containing intermediate was a mixture of the threo and erythro forms, and no optical activity could be found, suggesting that its formation might have involved nonstereospecific C~. -C~ epoxidation followed by non-enzymatic hydrolysis of the epoxide.