Extraction, Isolation and Characterization of Bioactive Compounds from Euphorbia neriifolia (L.) Leaf and Evaluation of their Antioxidant Activity

Background Amidst the identification of numerous secondary chemicals from Euphorbia neriifolia, there is a desperate need for the development of primary metabolite separation techniques. Objectives In order to do that, bioactive chemicals from Euphorbia neriifolia (L.) leaf were extracted, isolated, and characterized. Subsequently, their antioxidant activity was evaluated. Methods In this study, the determination of linoleic acid (LA) in petroleum ether extract (PEE) of Euphorbia neriifolia leaf (ENL) was carried out the first time by using thin-layer chromatography (TLC) and high-performance thin-layer chromatography (HPTLC) methods. Results The chromatographic analysis of the PEE of ENL shows better spots and well-separated peak of LA with 0.49 retention factor (Rf) value and 22.54 ng LA content. The linearity of the calibration curve ranges from 5-25 ng spot with a high correlation coefficient. The proposed method was characterized by better accuracy close to 99.5%, well robustness, and good precision range from 0.183% (intra-day) to 0.242% (inter-day). The percentage (%) RSD, which determined the stability of standard LA, did not exceed 2% after time period of 12, 24, 36, 48, and 72 h. The GC-MS analysis revealed the presence of different types of low or high-molecular-weight phytocompounds of varying quantities from the fractions of ENL. The FT-IR spectrum of ICs showed various peaks that confirmed the presence of C=C bending, C-H stretching, O-H stretching, CH2 stretching, and a carboxyl group. The H-1-NMR spectrum of the ICs from ENL confirmed the presence of octadecanoic in IC1, L-(+)-ascorbic acid dihexadecanoate in IC2, hexadecanoic acid in IC3, linoleic acid in IC4, and oleic acid in IC5, respectively. IC4 showed greater antioxidant activity in comparison to other compounds with an IC50 value of 3.9 +/- 0.01 mu g mL(-1). Conclusion Thus, the present study identified five different phytocompounds that may be utilized as an effective option for the cure of different diseases.