Correlation of the antioxidant capacity with the phenolic contents of Hypericum monogynum and Hypericum perforatum

This study was carried out to determine the total antioxidant activity and phenolic content of the two plants, that is, Hypericum monogynum and Hypericum perforatum. The antioxidant activities of both plants were carried out on the crude methanolic and subsequent solvent fractions in two concentrations, that is, 50 and 100 µg/ml. Among the tested samples, 80% methanolic and pure methanolic fractions showed good antioxidant activity in both plants. The antioxidant activity of NR-04 (combination of quercetin and astilbin) showed dose dependent effects and the highest activity was observed at 200 µg/ml. The phenolic contents of H. monogynum were quantified in all solvent fractions. The outstanding phenolic contents were found in 80% methanolic (7560 mg/100 g), pure methanolic (6923 mg/100 g), chloroform (5624 mg/100 g) and ethyl acetate fraction (5234 mg/100 g). Similarly H. perforatum was screened for phenolic contents, the highest phenolic contents were observed in methanol (7512 mg/100 g), ethyl acetate (7234 mg/100 g), chloroform (6513 mg/100 g) and in methanol 80% (6451 mg/100 g). The correlation between the antioxidant activity and phenolic contents were determined using word Excel. Weak correlation was found between the antioxidant activity and total phenolic contents.   Key words: Hypericum monogynum, Hypericum monogynum, antioxidant, phenolic content.