Antioxidant Activity Of Polyphenols From Larch Wood: An Amperometric Study

Purpose - The purpose of this paper is to determine the antioxidant activity of natural polyphenols from larch wood by the amperometric method.Design/methodology/approach - Direct measurements of antioxidant activity were carried out by the amperometric method in an oxidizing mode with glassy carbon as a working electrode, set potential +1.3V and using a flow-injection system with 2.2 mM phosphoric acid as the mobile phase with a flow rate of 1.2 ml/min.Findings - The reported results show the following values of antioxidant activity for the tested compounds: (-)- secoisolariciresinol - 0.199 +/- 0.002 mg/L (p < 0.05); isolariciresinol - 0.196 +/- 0.002 mg/L (p < 0.05); lariciresinol - 0.222 +/- 0.001 mg/L (p < 0.05); O-isopropylidene derivative of (-)- secoisolariciresinol - 0.143 +/- 0.002 mg/L (p < 0.05); (+)- dihydroquercetin - 0.153 +/- 0.002 mg/L (p < 0.05); and quercetin - 0.521 +/- 0.001 mg/L (p < 0.05). The last product was tested as the reference of a widely used current antioxidant. General tendencies of determined values of antioxidant activity for studied compounds are in good correlation with published data as determined by the t-BuOOH-initiated lipid peroxidation method.Practical implications - Described results show practical applicability of the amperometric method as being faster and cheaper in comparison to other methods, including oxygen radical absorbance capacity (ORAC) assay or 2,2' diphenyl-1-picrylhydrazyl (DPPH) reagent based assay.Originality/value - The described results show the first-time application of the amperometric method for the evaluation of the antioxidant activity of phenolic compounds from larch wood.