This enzyme catalyses one of the steps in the anhydrofructose pathway, which leads to the degradation of glycogen and starch via 1,5-anhydro-D-fructose [1,2]. The other enzymes involved in this pathway are EC?4.2.1.110?(aldos-2-ulose dehydratase), EC?4.2.1.111?(1,5-anhydro-D-fructose dehydratase) and EC?4.2.2.13?[exo-(1¡ú4)-¦Á-D-glucan lyase]. Ascopyrone P is an anti-oxidant [2].