Chemical characterization of water and ethanolic extracts of Turkish propolis by HPLC-DAD and GC-MS

Abstract

This study aims to determine the qualitative and quantitative contents of Turkish propolis collected from various regions of Turkey using high-performance liquid chromatography with the diode-array detector (HPLC-DAD) and gas chromatography-mass spectrometry (GC-MS) in water and ethanolic extracts. In HPLC-DAD analyses, it was determined that water extract of Turkish propolis contains phenolic acids such as caffeic acid (204.00 µg/mL), trans-cinnamic, chlorogenic, and caffeoylquinic acids, responsible for its antioxidant activity; whereas, the ethanolic extract of Turkish propolis contains chrysin (641.33 µg/mL), caffeic acid phenethyl ester (630.67 µg/mL), pinocembrin (572.67 µg/mL), galangin (534.11 µg/mL), naringenin (372.39 µg/mL), and also kaempferol, trans-cinnamic acid, caffeic acid, myricetin, and quercetin. GC-MS analyses showed that ethanolic extract of propolis contains caffeic acid by Rtx-1 column and the water extract of propolis contains quinic acid and ferulic acid by Rtx-5ms column. Various sugar derivatives were detected by both columns in water and ethanolic extracts of Turkish propolis. HPLC-DAD can be considered as a more effective method than GC-MS for the chemical characterization of propolis. Water extract of Turkish propolis can be a good source of raw materials for various sectors, as it is both cheap and has less health risk than ethanolic extract, and is suitable for human use.