C-2 AND C-3 OXIDATION OF D-GLC, AND C-2 OXIDATION OF D-GAL BY PYRANOSE DEHYDROGENASE FROM AGARICUS-BISPORUS

The quinone-dependent sugar oxidoreductase, pyranose dehydrogenase pur ified from the basidiomycete Agaricus bisporus catalyzed C-2 and C-3 o xidation of D-Glc to D-arabino-hexos-2-ulose (2-keto-D-Glc) and, prefe rentially, D-ribo-hexos-3-ulose (3-keto-D-Glc). The two aldoketoses ac cumulated only transiently in the reaction mixture being continually c onverted to the same end-product, D-erythro-hexos-2,3-diulose (2,3-dik eto-D-Glc). D-Gal was oxidized by pyranose dehydrogenase and 1,4-benzo quinone exclusively at C-2 to produce D-lyxo-hexos-2-ulose (2-keto-D-G al). Structures of the enzyme reaction products were deduced from thei r N,N-diphenylhydrazone derivatives. (C) 1998 Elsevier Science Ltd. Al l rights reserved.