Specific and Sensitive Determination Methods for 1,5-Anhydro-D-fructose.

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 (0-501a g/mL) to 1,5-AF and could perform on a small scale (sample 20 ,a L) on a microtitre plate.

Inhibition of <i>Agaricus </i>tyrosinase by 1, 5-anhydro-D-fructose and its application to anti-browning of food materials

“…このことは 1, 5-AF によるチロシナーゼ反 応の阻害の可能性を示す. 1, 5-AF は水中でケト型, エ ノール型, 水和型の平衡構造 16) をとり, 強い還元力を 持つ 17) . このうちケト型構造はチロシナーゼ反応を阻 害すると考えられているコウジ酸のピロン構造に類 似しており, 酵素との相互作用が期待できたため, 本 研究ではチロシナーゼに対する 1, 5-AF の阻害作用を 明らかにすることを試みた.…”