Abstract

The aim of the present investigation was to determine the influence of solvents (possessing different dielectric constant values) and geographical location on the Total Phenolic Content (TPC) and antioxidant activity of extracts of Bridelia retusa bark. The bark was collected from two different geographical locations of India [Maharashtra (MAH) and Andhra Pradesh (AP)]. The highest extractive values were found to be as 20.70±0.56 %w/w and 18.43 ± 0.97 %w/w in case of methanolic extracts of Bridelia retusa bark collected from MAH and AP regions respectively while the total polyphenolic contents in the methanolic extract ofBridelia retusa bark were 32.52 ± 0.24 mg/100 gm and 28.04±0.67 mg/100gm in MAH and AP regions respectively. The methanolic extract of the species from MAH exhibited the highest radical scavenging activity while that from AP showed less scavenging activity. The extracts showed a positive correlation between the polyphenol contents and solvent’s dielectric constant (R=0.728, P<0.05). This suggests that dielectric constant value significantly influences the choice of solvent for extraction as well as the total phenolic contents and subsequently the antioxidant activity of the plant extract.

Key words: Dielectric constant, total phenolic content (TPC), DPPH radical scavenging activity, Bridelia retusa.