Abstract
It was found by paper chromatography that a new derivative of L-ascorbic acid having reducing power on both 2,6-dichlorophenol-indophenol and silver nitrate was formed in the incubation mixture containing maltose, sodium L-ascorbate, thiourea and a partially purified α-glucosidase from Aspergillus niger. After purification by precipitation with lead acetate and by successive separation chromatographically on paper and on Sephadex column, the new derivative was isolated as powdered preparation and assumed to be ascorbic acid glucoside from various data, viz., R_F values, absorption spectra at acidic, neutral and alkaline pH, products by hydrolysis with a highly purified α-glucosidase from Aspergillus niger, and absorption spectra of reaction products with both 2,4-dinitrophenylhydrazine and diazotized p-nitroaniline. D-Araboascorbic acid also appeared to act as glucosyl acceptor, but was less efficient. The activity of the formation of ascorbic acid glucoside was observed in the molds belonging to Aspergillus and Penicillium, but not to Rhizopus.
