The propolis extracts were analyzed by HPLC using a Shimadzu apparatus equipped with a CBM-20A controller, a LC-20AT quaternary pump, a SPD-M 20A diode-array detector, and Shimadzu LC solution software, version 1.21 SP1. A Shimadzu Shim-Pack CLC-ODS column (4.6 mm x 250 mm, particle diameter of 5 µm, pore diameter of 100 Å) was used. The mobile phase consisted of methanol (B), and of a solution of water-formic acid (0.1% v/v), pH 2.7 (A). The method consisted of a linear gradient of 20-95% of B over a period of 77 minutes at a flow rate of 0.8 ml/min. Detection was set at 275 nm.
Propolis extracts were diluted with 5 ml of methanol (HPLC grade) in 10 ml volumetric flasks, subjected to sonication for 10 minutes and filled to volume with Milli-Q water. The samples were filtered through a 0.45 µm filter before analysis.
Propolis extracts were diluted with 5 ml of methanol (HPLC grade) in 10 ml volumetric flasks, subjected to sonication for 10 minutes and filled to volume with Milli-Q water. The samples were filtered through a 0.45 µm filter before analysis.
