Antioxidant activity of phenolics and flavonoids fractions of bark of babul (Acacia nilotica) and arjun (Terminalia arjuna)
Loading...
Date
2016
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU
Abstract
The present study was undertaken to study the effect of extraction techniques on total
phenolics, flavonoids and antioxidant activity of bark of babul (Acacia nilotica) and arjun (Terminalia
arjuna). Methanolic extracts were obtained by cold and hot extraction techniques followed by liquidliquid
partitioning of methanolic extracts with various solvents (hexane, dichloromethane, chloroform,
ethyl acetate and butanol). Extract yield of methanolic extracts of bark of babul and arjun obtained by hot
extraction technique (10.889 to 12.623 g/100g) was higher in comparison to cold extraction technique
(6.528 to 7.396 g/100g). Similarly, extract yield of various solvent fractions of aqueous layers of
methanolic extracts of bark of babul and arjun obtained by hot extraction technique (0.027 to 2.177
g/100g) was higher in comparison to cold extraction technique (0.011 to 2.523 g/100g). Total phenolics
content in methanolic extracts of bark of arjun and babul obtained by hot extraction technique (45.377 to
49.380 mg GAE/g) were higher in comparison to cold extraction technique (13.251 to 32.926 mg
GAE/g). Similarly, total flavonoids content in methanolic extracts of bark of arjun and babul obtained by
hot extraction technique (15.071 to 18.895 mg CE/g) were higher in comparison to cold extraction
technique (4.353 to 10.752 mg CE/g). In various solvent fractions of aqueous layers of methanolic
extracts of bark of babul obtained by both extraction techniques, total phenolics and total flavonoids
contents were highest in ethyl acetate fraction followed by butanol, residual aqueous, dichloromethane,
chloroform and hexane fractions. In various solvent fractions of aqueous layers of methanolic extracts of
bark of arjun obtained by both extraction techniques, total phenolics and total flavonoids contents were
highest in residual aqueous fraction followed by butanol, ethyl acetate, dichloromethane, chloroform and
hexane fractions. The lower values of IC50 represent higher DPPH free radical scavenging activity.
Amongst extraction techniques, methanolic extracts of bark of babul and arjun obtained by hot extraction
technique exhibited higher antioxidant activity (IC50 67.7 and 134.8 μg/mL) in comparison to cold
extraction technique (IC50 71.7 and 180.5 μg/mL). In various solvent fractions of aqueous layers of
methanolic extracts of bark of babul obtained by both extraction techniques, ethyl acetate fraction
exhibited the highest antioxidant activity (IC50 24.9 and 35.2 μg/mL) followed by butanol, residual
aqueous/dichloromethane, chloroform and hexane fractions. In various solvent fractions of aqueous layers
of methanolic extracts of bark of arjun obtained by both extraction techniques, ethyl acetate fraction
exhibited the highest antioxidant activity (IC50 27.7 and 38.1 μg/mL) followed by butanol, residual
aqueous, chloroform, dichloromethane and hexane fractions.
Description
Keywords
Extraction, Alcohols, Fractionation, Wastes, Solvents, Plant extracts, Aromatic compounds, Phenols, Antioxidants, Layering