A green, rapid and efficient protocol for apigenin extraction from Biophytum poterioides Edgew.

Abstract

The present study standardized a green protocol for extracting apigenin from Biophytum poterioides. Natural deep eutectic solvents (NADES) and green extraction techniques like microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) were adopted and optimized by response surface methodology. Based on the statistically evaluated results, the optimal solvent was the choline chloride: oxalic acid (NADE 5) at a molar ratio 1:1 with 30% (v/v) of water. MAE using a solid-to-solvent ratio 1:10 for 6 min duration was identified as the optimum condition for the effective extraction of apigenin. A sixfold increase of apigenin was obtained using NADE 5 (1395.767 ± 5.083 mg/L) compared to ethanol (255.718 ± 2.930 mg/L) at the optimal condition. The FT-IR studies aided in confirming the interaction of apigenin with NADES 5. Furthermore, antioxidant studies demonstrated that the NADES 5 extract had a substantial ability to scavenge DPPH radical (IC50 =219.572 μg/ml). Appraisal of the greenness of the developed methods was evaluated using the novel Analytical GREEnness (AGREEprep) metric. The results confirmed that the combination of NADES and MAE offers a rapid and cheap alternative to conventional solvents for sustainable and green extraction and allows easy transfer of the proposed methodology to large-scale extraction of apigenin.