Antioxidant activity of some phanerogam plant extracts

Abstract

Nine phanerogam plants (common lady's-mantle, bear's garlic, common sweet flag, agrimony, goldenrod, common speedwell, european mistletoe, horsetail and milfoil) were evaluated regarding their total flavonoid contents and antioxidant activity. The flavonoid contents ranged from 0.72 (goldenrod) to 0.25 mmol/g dry matter (horsetail). The contents of quercetin, rutin, kaempferol and myricetin were quantified by high performance liquid chromatography. Quercetin content was found to be very low in goldenrod and mistletoe extracts (0.20 μmol/g dry matter in european mistletoe) and almost undetectable in the other seven extracts. The rutin content was much higher, ranging from 96.25 (goldenrod) to 0.49 μmol/g dry matter (common sweet flag). Except for horsetail, kaempferol was found in all other eight extracts, the biggest quantity (2.15 μmol/g dry matter) being in the goldenrod extract. Myricetin was only found in goldenrod and agrimony (0.35 and 0.08 μmol/ g dry matter respectively). Goldenrod and milfoil showed the highest values for the antioxidant activity, expressed as mol quercetin equivalent, in the DPPH · (1,1-diphenyl-2-picrylhydrazyl) method, namely 0.00542 and 0.00532. These results suggest them to be used as natural sources of antioxidants instead of synthetic ones.