Functionality study of Na6PMo11FeO40 as a mushroom tyrosinase inhibitor

The inhibitory effects of iron-substituted phosphomolybdic acid (Na6PMo11FeO40, abbreviated as PMo11Fe) on mushroom tyrosinase were investigated. The Native-PAGE results show that PMo11Fe has an inhibitory effect on tyrosinase. A spectrophotometric analysis shows that PMo11Fe is a reversible and noncompetitive inhibitor with K-I= K-IS = 0.47 mmol L-1. The effects of PMo11Fe on the preservation of lotus root slices were studied. The results show that PMo11Fe can significantly slow the browning rate of lotus root slices, inhibit the activity of polyphenol oxidase (PPO), enhance the activity of peroxidase (POD) and superoxide dismutase (SOD), maintain high levels of glutathione (GSH), ascorbic acid (ASA) and sucrose and control the peroxidation degree of fresh-cut fruits and vegetables. This study may help to elucidate the design of mushroom tyrosinase inhibitors of polyoxometalates (abbreviated as POMs) and a theoretical basis for the use of POMs to inhibit fruit spoilage. (c) 2014 Elsevier Ltd. All rights reserved.