74516-89-5Relevant articles and documents
Rare keto-aldoses from enzymatic oxidation: Substrates and oxidation products of pyranose 2-oxidase
Freimund, Stefan,Huwig, Alexander,Giffhorn, Friedrich,Koepper, Sabine
, p. 2442 - 2455 (2007/10/03)
Pyranose oxidases are known to oxidise D-glucose, D-xylose and L- sorbose to keto-aldoses, biochemically interesting compounds that may also be used for synthetic purposes in a variety of reactions. In this study pyranose oxidase from the basidiomycete Peniophora gigantea was investigated, and it was found that this enzyme is able to oxidise a broad variety of substrates very effectively. In analogy to its natural mode of action, most substrates are oxidised regioselectively in position 2. Certain compounds, however, are converted into 3-keto derivatives, and the enzyme even exhibits transfer potential, that is, disscharides are formed from β-glycosides of higher alcohols. Substrates that may be oxidised at C-2 in yields between 40-98% are D-allose, D-galactose, 6-deoxy-D-glucose, D-gentiobiose, α-D-glucopyranosyl fluoride and the very interesting 3-deoxy-D-glucose. 1,5-Anhydro-D-glucitol (1-deoxy-D-glucose) is very effectively oxidised in position 2 in 98% yield and additionally gives a product of dioxidation at C-2 and C-3 upon prolonged reaction time Selective oxidation at C-3 was found for 2-deoxy-D-glucose in very good yields and for methyl β-D-gluco- and methyl β-galactopyranoside in lower yields. All oxidation products were unequivocally characterised by NMR spectroscopy and/or chemical derivatisation. In addition, the kinetic data of the enzymatic reactions were determined for all substrates. On the basis of these data and the structural characteristics of the substrates, a model for the minimal structural requirements of the enzyme-substrate interaction is suggested. The enzyme presumably uses two different binding modes for the regioselective C-2 and the C-3 oxidations, which are described.
