3.5.1. Radical Scavenger Assay

DPPH radical scavenging activity of compounds was tested as described [51].

Compounds were dissolved in MeOH, and the solutions (160 μL) were dispensed into wells of a 96-well microplate. In all, 40 μL of the DPPH (Sigma-Aldrich, Steinheim, Germany) solution in MeOH (1.5 × <sup>10</sup>−<sup>4</sup> M) was added to each well. Concentrations of compounds in mixture were 10 and 100 <sup>μ</sup>M. The mixture was shaken and left to stand for 30 min, and the absorbance of the resulting solution was measured at 520 nm with a microplate reader MultiscanFC (ThermoScientific, Waltham, MA, USA). Radical scavenging activity of all compounds at 100 μM were presented as percent of MeOH data, and the concentration of DPPH radical scavenging at 50% (EC50) was calculated for some compounds.
