Some indazoles as alternative inhibitors for potato polyphenol oxidase.

Abstract

Fresh-cut vegetables and fruits have gained attention among consumers because of their fresh appearance, lack of pollution, nutrition, and convenience. However, in fresh-cut foods, enzymatic browning is the main problem. Polyphenol oxidase (PPO) is a vital enzyme involved in the process of enzymatic browning. In this study, PPO was purified from potato using Sepharose 4B-l-tyrosine-p-aminobenzoic acid affinity chromatography and the effect of some indazoles on the enzyme was determined. The enzyme was purified with a specific activity of 52,857.14EU/mg protein and 21.26-purification fold. Indazoles exhibited inhibitor properties for PPO with IC50 values in the range of 0.11-1.12mM and Ki values in the range of 0.15 ±0.04-3.55±0.88mM. Among these compounds, 7-chloro-1H-indazole was shown as the most potent PPO inhibitor (Ki : 0.15±0.04mM). Determination of the enzyme's inhibition kinetics will simplify the testing of candidate PPO inhibitors.