Biotransformations oxidation with laccases

In extension to the above experiments the usefulness of the laccase/[G2]-PEG5k-[G2] complex for biotransformations of highly hydrophobic substrates is evaluated with BP and HBT. The reaction is followed by UV-Vis spectroscopy. Figure 7. It is seen that, despite the notable difference in the intensities, the spectral characteristics of reaction mixtures with BP (Figure 7A) are rather similar to those of mixtures without BP (Figure 7B). Obviously HBT is not spectroscopically suitable as mediator for the analysis of laccase mediated transformations of BP, since previous studies have shown that it can also be oxidized by laccase, and the reaction produces) possess absorption maxima in the same spectral region as the BP quinones (19, 20). 

Some microbial pathogens can circumvent the defensive response of plants by biotransforming the antimicrobial stilbenoids in a multi-step oxidative detoxification process [106], Research has shown that the pathogenicity of B. cinerea strains is positively correlated with these fungi s production of blue-copper oxidases known as stilbene oxidases or laccases [127,128]. These enzymes are polyphenol oxidases capable of catalyzing the oxidation and polymerization of numerous phenolic substrates [129,130,131,132]. It has been shown that 1 is readily transformed in the presence of B. cinerea culture medium filtrates that contain laccases [107]. Recently, six resveratrol dimers (restrytisols A-C... 

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