Assessment of free-radical scavenging activity of Gypsophila pilulifera: assay-guided isolation of verbascoside as the main active component

ABSTRACT

Gypsophila pilulifera, Boiss & Heldr, Caryophyllaceae, is a perennial medicinal herb that grows in the southwestern region of Turkey. Except for only one report on the isolation of cytotoxic saponins from the underground parts of G. pilulifera, there are no published thorough phytochemical or bioactivity studies on this species. In the present study, the free-radical scavenging activity of extracts and fractions of the stems of G. pilulifera was evaluated, using a slightly modified and more precise version of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, reported here for the first time. The DPPH assay-guided HPLC-PDA-purification of the active solid-phase extraction fraction (50% methanol in water) of the methanolic extract exhibited verbascoside as the main free-radical scavenger present in this species. The structure of this active compound was resolved by spectroscopy, and the free-radical scavenging potential of verbascoside was determined.