Proanthocyanidins Extracted from Rhododendron pulchrum Leaves as Source of Tyrosinase Inhibitors: Structure, Activity, and Mechanism

PLoS One. 2015 Dec 29;10(12):e0145483. doi: 10.1371/journal.pone.0145483. eCollection 2015.

Abstract

The objective of this study was to assess the structure, anti-tyrosinase activity, and mechanism of proanthocyanidins extracted from Rhododendron pulchrum leaves. Results obtained from mass spectra of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS) revealed that proanthocyanidins were complex mixtures of procyanidins, prodelphinidins, propelargonidins, and their derivatives, among which procyanidins were the main components. The anti-tyrosinase analysis results indicated that the mixtures were reversible and mixed competitive inhibitors of tyrosinase. Interactions between proanthocyanidins with substrate (L-tyrosine and 3,4-dihydroxyphenylalanine) and with copper ions were the important molecular mechanisms for explaining their efficient inhibition. This research would provide scientific evidence for the use of R. pulchrum leaf proanthocyanidins as new novel tyrosinase inhibitors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agaricales / enzymology
  • Copper / pharmacology
  • Drug Interactions
  • Enzyme Inhibitors / chemistry*
  • Enzyme Inhibitors / isolation & purification
  • Enzyme Inhibitors / metabolism
  • Enzyme Inhibitors / pharmacology*
  • Molecular Docking Simulation
  • Monophenol Monooxygenase / antagonists & inhibitors*
  • Monophenol Monooxygenase / metabolism
  • Plant Leaves / chemistry*
  • Proanthocyanidins / chemistry*
  • Proanthocyanidins / isolation & purification
  • Proanthocyanidins / metabolism
  • Proanthocyanidins / pharmacology*
  • Rhododendron / chemistry*

Substances

  • Enzyme Inhibitors
  • Proanthocyanidins
  • Copper
  • Monophenol Monooxygenase

Grants and funding

The present investigation was supported by the Natural Science Foundation of China (No. 31501414, 21362014, 31260082), the Open Project Program of Key Laboratory of Functional Small Organic Molecule, Ministry of Education, Jiangxi Normal University (KLFSKF-201419). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.