Abstract
The ultraviolet spectrum of 1, 5-anhydro-D-fructose (1, 5-anhydro-D-arabino-hexo-2-ulose, 1, 5-AF) showed two absorption peaks at 215 and 266 nm, and the absorption at 215 nm was higher . The molar absorptivity at 215 nm was low (34 M-1· cm-1) and was unsuitable for the assay. The conven tional methods for the determination for total sugar were unsuitable for 1, 5-AF because the phenolsulfuric acid method gave only 15% value of glucose and no coloration by the anthrone-sulfuric acid method. On the other hand, 1, 5-AF reduced Cu2+ (the method of Somogyi and Nelson or neocuproine assay) and Fe3+(the method of Park and Johnson) even at 35°C. The former reaction enabled the specific determination of 1, 5-AF in the presence of the other hexoses and pentoses . Neocuproine assay for reducing sugars was sensitive (0-50μg/mL) to 1, 5-AF and could perform on a small scale (sample 20μL) on a microtitre plate.
