Purification and GC-MS Spectroscopic Identification of Active Antioxidant Principles in Ethanol Extract of Phyllanthus amarus Leaves

Background and Objective: The presence of natural antioxidant activity in plants has been well acknowledged worldwide. There is increasing demand for a natural antioxidant to replace synthetic additives in the food and pharmacological industries. The main goal of this study was to fractionate and identify active antioxidant principles in Phyllanthus amarus leaves. Materials and Methods: Samples of matured and healthy looking leaves of Phyllanthus amarus were collected. Extraction of the plant was done using ethanol and fractionation with different solvents of varied polarity via column chromatography, starting from n-hexane, chloroform, ethyl acetate, ethanol, methanol and lastly, water. The fractions were screened for antioxidant activity by a 2, 2-Diphenylpicrylhydrazyl (DPPH) assay. Fraction 10b shows high antioxidant activity and was subjected to further analysis using the GC-MS and FTIR analysis and 32 compounds were identified. Total phenol and total flavonoid contents were analyzed by the Folin Ciocalteu method and aluminium chloride colorimetric method, respectively. Results: The result for total antioxidant activity shows that fraction 10b has the highest antioxidant activity (83 mg mLG 1 ) while fraction 2a shows the lowest antioxidant activity (13 mg mLG 1 ). The result for total phenol content showed that fraction 10b has the highest phenol content (430 mg mLG 1 ) and fraction 2a has the lowest phenol content (9 mg mLG 1 ). Fraction 3b shows the highest concentration of total flavonoid content (143 mg mLG 1 ) while fraction 2a shows the lowest concentration (23 mg mLG 1 ). The result shows a strong positive correlation between total antioxidant and total phenol content. The relationship between total antioxidant and total flavonoid content shows negative. Conclusion: This present study concluded that the high phenol content present in Phyllanthus amarus leaves is entirely responsible for the antioxidant activity of the plant.