Characterization of a New Flavone and Tyrosinase Inhibition Constituents from the Twigs of Morus alba L

Molecules. 2016 Sep 2;21(9):1130. doi: 10.3390/molecules21091130.

Abstract

The twigs of Morus alba L. were found to show strong tyrosinase inhibition activity, and the responsible active components in the extract were further investigated in this study. A flavone, named morusone (1), and sixteen known compounds 2-17 were isolated from M. alba twigs and their structures were identified by interpretation of the corresponding ESI-MS and NMR spectral data. In the tyrosinase inhibitory test, the compounds steppogenin (IC50 0.98 ± 0.01 µM), 2,4,2',4'-tetrahydroxychalcone (IC50 0.07 ± 0.02 µM), morachalcone A (IC50 0.08 ± 0.02 µM), oxyresveratrol (IC50 0.10 ± 0.01 µM), and moracin M (8.00 ± 0.22 µM) exhibited significant tyrosinase inhibition activities, much stronger than that of the positive control kojic acid. These results suggest that M. alba twig extract should served as a good source of natural tyrosinase inhibitors for use in foods as antibrowning agents or in cosmetics as skin-whitening agents.

Keywords: Morus alba; phenolic compounds; twigs; tyrosinase inhibition.

MeSH terms

  • Enzyme Inhibitors* / chemistry
  • Enzyme Inhibitors* / isolation & purification
  • Flavones* / chemistry
  • Flavones* / isolation & purification
  • Fungal Proteins / antagonists & inhibitors*
  • Fungal Proteins / chemistry
  • Monophenol Monooxygenase / antagonists & inhibitors*
  • Monophenol Monooxygenase / chemistry
  • Morus / chemistry*
  • Plant Stems / chemistry*

Substances

  • Enzyme Inhibitors
  • Flavones
  • Fungal Proteins
  • Monophenol Monooxygenase