Preparation and Antioxidative Activity of 1, 5-Anhydrofructose

Abstract

A simple enzymic method for the preparation of 1, 5-anhydrofructose (1, 5-AF) and its antioxidative activity were investigated. α-1, 4-glucan lyase (EC 4 .2.2.13, GLase) was extracted and purified from red seaweed, Gracilaria verrrucosa. One-hundred-and-fifty grams of 1, 5-AF was obtained from 360 g of waxy maize starch by digestion with the purified GLase and the following purification of the product by ion-exchange resins and gel filtration. The purity of the product was 98 .6% by HPLC using an ionexchange resin (MC1 GEL CK08S). The product, 1, 5-AF, was identified by ^IH-¹³C COSY NMR, and the [α] _D²⁵ was -16.8°. The antioxidative activity of 1, 5-AF was examined by comparison with that of ascorbic acid (VC) for preventing the oxidation of linoleic acid . The antioxidative activity of 1, 5-AF was found to be approximately 1.8-fold that of VC by the methods using thiocyanate and 2-thiobarbituric acid.