HPLC determination of phenolic acids and antioxidant activity in concentrated peat extract—a natural immunomodulator

The aim of this study was to devise a method for identification and quantification of phenolic acids in concentrated peat extract samples. The simple reversed-phase HPLC method for simultaneous determination of several phenolic acids was developed. The method was validated and it was suitable for the analysis of phenolic acids in peat extracts. This method allowed identifying eight phenolic acids in peat extracts. Phenolic profiles of two samples of peat extract obtained from different medicinal peats were similar, although variations in amounts of individual phenolic acids were observed. Also, slight variations in total phenolic content were detected. The antioxidant activity of peat extracts was evaluated with spectrophotometric ABTS assay. Differences in antioxidant activity were observed for two samples of peat extract produced from different peat varieties. This differences probably reflected phenolic composition of peat extracts.