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The degradation of three non-phenolic fl-Oo 4 diarylpropane lignin model compounds was studied in cultures of the white-rot fungus Phlebia radiata. The degradation pattern of the model compound 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-l,3-diol (I) was also compared with that of Phanerochaete chrysosporium under conditions where both fungi were cultivated without agitation in an oxygen atmosphere. Compound I was readily degraded by both fungi, and qualitatively the degradation patterns were quite similar. The product, after Ca-C a bond cleavage, was veratraldehyde (IV) which was almost stoichiometrically reduced to veratryi alcohol (V). However, large amounts of V were detected only in P. chrysosporiurn cultures. Experiments with the model compound 1-(4-ethoxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)propane-l,3-diol (II) showed that in the presence of II, the total amount of veratryl compounds accounted for [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33].LM in standing cultures of Phlebia radiata. The model compound 1-(3,4-dimethoxyphenyl)-2-(4-methoxyphenoxy) propane-l,3-diol (III) was more readily degraded than I and II. The results indicated that, in P. radiata cultures, the acting enzymes were lignin peroxidases and IV reducing enzyme, while laccase was less important.

Three different hexameric lignin model compounds were synthesised. Two different synthesis routes were used to obtain trimeric lignin model compounds containing ß-aryl ether bonds. The trimers were dimerised using enzymatic oxidation to hexamers containing ß-O-4 and 5-5' bonds. The hexamers were characterised with and 13 C NMR spectroscopy äs well äs with mass spectrometry.

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