TRANSFORMATION OF 2-HYDROXYDIBENZOFURAN BY LACCASES OF THE WHITE-ROT FUNGI TRAMETES-VERSICOLOR AND PYCNOPORUS-CINNABARINUS AND CHARACTERIZATION OF OLIGOMERIZATION PRODUCTS
U. Jonas et al., TRANSFORMATION OF 2-HYDROXYDIBENZOFURAN BY LACCASES OF THE WHITE-ROT FUNGI TRAMETES-VERSICOLOR AND PYCNOPORUS-CINNABARINUS AND CHARACTERIZATION OF OLIGOMERIZATION PRODUCTS, Biodegradation, 8(5), 1997, pp. 321-328
Laccase, a ligninolytic enzyme, was secreted by each of the white rot
fungi Trametes versicolor and Pycnoporus us cinnabarinus during growth
in a nitrogen-rich medium ender agitated conditions. After addition o
f 2-hydroxydibenzofuran to cell-free supernatants of the cultures, yel
low precipitates were formed. These precipitates were poorly soluble i
n water and therefore readily separated from the supernatant. The prod
ucts formed were more hydrophobic than the substrate, as indicated by
their longer retention times on a reverse phase high-performance liqui
d chromatography column. Mass spectrometric analysis of the purified p
roducts indicated the formation of oligomers. Analysis of the mixture
of products by gas chromatography and mass spectrometry after derivati
zation with diazomethane suggested the formation of at least three dim
eric and nine trimeric, products. Carbon-carbon and carbon-oxygen bond
s were identified in the dimers and trimers, respectively. The nuclear
magnetic resonance spectrum of the main dimer suggested coupling of t
he two monomers at the carbon one position.