Synthesis, antioxidant and anti-tyrosinase activity of 1,2,4-triazole hydrazones as antibrowning agents

A series of 1,2,4-triazole hydrazones (1-16) were synthesized, and their inhibitory activities and mechanisms on tyrosinase were investigated by ultraviolet spectrophotometry, fluorescence quenching, molecular docking study, etc. Most of compounds possessed potent tyrosinase inhibitory activity. Thereinto, compound 9 presented the superior activity with IC50 of 0.9 mu M, which was markedly lower than the standard kojic acid (IC50 = 64.1 mu M). Compound 9 not only interacted with copper ions in the active center of the enzyme but also bound to the enzyme-substrate complex, indicating that it was a competitive-noncompetitive mixed inhibitor. Additionally, it also displayed potent DPPH scavenging activity. Antibrowning test showed that compound 9 effectively reduced the enzymatic browning of fresh-cut potatoes. Furthermore, compound 9 exhibited low cytotoxic activity against human normal cell line with IC50 of 49.9 mu M. Overall, the present study suggests that these compounds may serve as lead molecules for developing novel antibrowning agents in food industry.

Automated summary

A series of 1,2,4-triazole hydrazones were synthesized and evaluated for their inhibitory activities on tyrosinase. Compound 9 showed superior inhibitory activity, competitive-noncompetitive mixed inhibition mechanism, potent DPPH scavenging activity, and effective antibrowning effect on fresh-cut potatoes. It also displayed low cytotoxicity against human normal cell line, suggesting its potential as lead molecules for novel antibrowning agents in the food industry.