Extraction Behavior and Quantitative Profiling of Prenylated Flavonoids from Hops (Humulus lupulus L.) Under Varying Solvent Polarity, Temperature, and Cryogenic Pretreatment

Molecules. 2025 Dec 12;30(24):4743. doi: 10.3390/molecules30244743.

Abstract

Prenylated flavonoids from hops (Humulus lupulus L.) represent a distinctive class of bioactive compounds with notable antioxidant and health-promoting properties. This study investigated the extraction behavior and quantitative profiles of three major prenylflavonoids-xanthohumol (XN), isoxanthohumol (IXN), and 8-prenylnaringenin (8-PN)-under varying solvent polarity (ethanol vs. methanol), extraction temperature (50-200 °C), and sample pretreatment (mechanical vs. cryogenic homogenization). Extractions were performed using accelerated solvent extraction (ASE), and compounds were quantified by HPLC-DAD. Ethanol exhibited higher extraction efficiency than methanol, while cryogenic pretreatment markedly enhanced the release of all target analytes. The maximum recovery was achieved at 150 °C for XN, 200 °C for IXN, and 100 °C for 8-PN. Multifactor statistical analysis (MANCOVA, ANOVA) confirmed significant effects of solvent, temperature, and pretreatment, as well as their interactions (p < 0.001). The combination of ASE and cryogenic homogenization enables efficient isolation and precise quantification of prenylated flavonoids from hops, providing a valuable analytical framework for the development of standardized hop extracts and bioactive formulations.

Keywords: 8-prenylnaringenin (8-PN); HPLC-DAD quantification; accelerated solvent extraction (ASE); cryogenic homogenization; extraction temperature; hops (Humulus lupulus L.); isoxanthohumol (IXN); prenylated flavonoids; solvent polarity; xanthohumol (XN).

MeSH terms

  • Chromatography, High Pressure Liquid
  • Flavanones / chemistry
  • Flavanones / isolation & purification
  • Flavonoids* / chemistry
  • Flavonoids* / isolation & purification
  • Humulus* / chemistry
  • Plant Extracts* / chemistry
  • Prenylation
  • Propiophenones / chemistry
  • Propiophenones / isolation & purification
  • Solvents* / chemistry
  • Temperature
  • Xanthones / chemistry
  • Xanthones / isolation & purification

Substances

  • Flavonoids
  • Solvents
  • xanthohumol
  • Propiophenones
  • Plant Extracts
  • Xanthones
  • Flavanones
  • isoxanthohumol
  • 8-prenylnaringenin