Anti-polyphenol oxidase properties of total flavonoids from young loquat fruits: inhibitory activity and mechanism

Bioengineered. 2021 Dec;12(1):640-647. doi: 10.1080/21655979.2021.1886387.

Abstract

This study investigated anti-polyphenol oxidase activity and mechanism of purified total flavonoids (PTF) from young loquat fruits. PTF remarkably inhibited the activity of polyphenol oxidase (PPO) with an IC50 value of 21.03 ± 2.37 μg/mL. Based on enzyme kinetics, PTF was found to be a potent, mixed-type, and reversible inhibitor of PPO. The fluorescence intensity of PPO was quenched by PTF through forming a PTF-PPO complex in a static procedure. Therefore, this study authenticated PTF as an efficient PPO inhibitor, which would contribute to their utilization in food industry.

Keywords: Polyphenol oxidase; inhibitory mechanism; total flavonoids; young loquat fruits.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catechol Oxidase* / antagonists & inhibitors
  • Catechol Oxidase* / metabolism
  • Enzyme Inhibitors* / analysis
  • Enzyme Inhibitors* / chemistry
  • Enzyme Inhibitors* / pharmacology
  • Eriobotrya / chemistry*
  • Flavonoids* / analysis
  • Flavonoids* / chemistry
  • Flavonoids* / pharmacology
  • Fruit / chemistry*
  • Kinetics

Substances

  • Enzyme Inhibitors
  • Flavonoids
  • Catechol Oxidase

Grants and funding

This work was supported by The Open Research Fund of Jiangsu Key Laboratory for Biomass Energy and Material (JSBEM202009), The Science and Technology Foundation of Suzhou (SNG201909) and The Foundation of Suzhou Academy of Agricultural Sciences (KJ(18)101).