Unusual isovalerylated flavonoids from the fruit of sea buckthorn (Elaeagnus rhamnoides) grown in Sokółka, Poland

Phytochemistry. 2019 Jul:163:178-186. doi: 10.1016/j.phytochem.2019.03.001. Epub 2019 Apr 3.

Abstract

Eight undescribed isorhamnetin glycosides, acylated with isovaleric acid were isolated from the fruit of sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson). Structures of the purified compounds were determined using one and two-dimensional NMR spectroscopy, mass spectrometry and chemical methods. In addition, the cytotoxic activity of the phenolic-rich fraction of sea buckthorn fruit and its major flavonoids against colon cell lines, HT-29, HCT-116 and Caco-2, was determined. While the phenolic fraction was moderately active against HT-29 and HCT-116, all investigated purified flavonoids showed significantly weaker activity. This is most probably the first report about isorhamnetin glycosides acylated with isovaleric acid.

Keywords: 3-methylbutanoic acid; Elaeagnaceae; Elaeagnus rhamnoides (L.) A. Nelson; Flavonoids; Fruit; Isorhamnetin; Isovaleric acid; Phenolic compounds; Sea buckthorn.

MeSH terms

  • Cell Survival / drug effects
  • Dose-Response Relationship, Drug
  • Fruit / chemistry*
  • Glycosides / chemistry
  • Glycosides / isolation & purification
  • Glycosides / pharmacology*
  • Hemiterpenes
  • Hippophae / chemistry*
  • Hippophae / growth & development
  • Humans
  • Molecular Conformation
  • Pentanoic Acids / chemistry
  • Pentanoic Acids / isolation & purification
  • Pentanoic Acids / pharmacology*
  • Poland
  • Quercetin / analogs & derivatives*
  • Quercetin / chemistry
  • Quercetin / isolation & purification
  • Quercetin / pharmacology
  • Structure-Activity Relationship
  • Tumor Cells, Cultured

Substances

  • Glycosides
  • Hemiterpenes
  • Pentanoic Acids
  • 3-methylquercetin
  • isovaleric acid
  • Quercetin