Extraction, Characterization and Evaluation of the Antioxidant Activity of Ximenia Americana in Sudan

Abstract

Background: Ximenia americana (wild plum), a shrub belonging to the Olacaceae family and native to tropical Africa, has long been used in traditional medicine for treating skin conditions, infectious diseases, and inflammatory disorders. The seeds of this plant contain a substantial amount of oil (approximately 27.71%) that is widely used in African communities for cosmetic and medicinal purposes. However, comprehensive scientific characterization of the seed oil and systematic evaluation of its antioxidant potential remain limited especially in Sudan.Methods: This study was designed to extract oil from X. americana seeds, characterize its physicochemical properties, and evaluate its antioxidant activity in Sudan. The oil was extracted using standard solvent extraction methods. The physicochemical properties—including color, odor, taste, boiling point, density, viscosity, refractive index, acid value, ester value, iodine value, peroxide value, and saponification value—were determined following standard protocols. The antioxidant activity was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Chemical constituents of the ethanol extract were identified by gas chromatography coupled to mass spectrometry (GC-MS) following saponification and methylation of fatty acid components. Phytochemical screening was performed to detect secondary metabolites including phenols, flavonoids, tannins, saponins, terpenoids, and alkaloids.Results: The GC-MS analysis successfully identified ten fatty acids in the seed oil, including four previously reported acids (palmitic, oleic, ximeninic, and lignoceric) and six additional acids (ceric, nervonic, montanic, ximenic, ximenoic, and lumequeic). Notably, ximeninic acid and ximenoic acid are unique long-chain fatty acids characteristic of this species. The seeds exhibited high protein content (19.77%) and oil content (27.71%). The oil was yellow, odorless, tasteless, and freely soluble in non-polar solvents. Key physicochemical parameters were: boiling point 157°C, density 0.9376 g/ml, refractive index 1.4770, acid value 0.2805, ester value 9.82, iodine value 47.59, peroxide value 30, and saponification value 11.43. The phytochemical screening revealed the presence of phenols, flavonoids, tannins, and other bioactive compounds that contribute to the oil's antioxidant and medicinal properties. The DPPH assay confirmed significant free radical scavenging activity, supporting the traditional use of the oil for therapeutic and cosmetic applications.Conclusion: The findings provide substantial scientific evidence that Ximenia americana seed oil is a rich source of bioactive fatty acids and phenolic compounds with notable antioxidant efficacy. The high oil and protein content, combined with the presence of unique ximeninic and ximenoic acids, underscore the potential of this plant as a valuable resource for nutraceutical development, cosmetic formulations, and possibly biodiesel production. Further purification and structural elucidation of the active phenolic compounds are recommended for the development of novel phytopharmaceuticals and therapeutic agents.