Isolation, Structural Characterization, and Antioxidant Activity of Bakuchiol and Fatty Acid Profiling of Psoralea corylifolia L. Seed Oil

Psoralea corylifolia L. is a medicinal plant containing valuable bioactive constituents, including bakuchiol and triglycerides. This study aimed to optimize extraction, characterize bakuchiol, determine fatty acid composition, and evaluate antioxidant activity. Five Soxhlet extraction protocols using solvents of varying polarities were investigated. Sequential extraction with methanol and aqueous methanol yielded the highest crude extract recovery (approximately 35.6%). However, hexane extraction followed by chloroform–methanol (2:1, v/v) extraction was selected for further investigation because of its suitability for enriching lipophilic constituents. Silica gel column chromatography separated triglyceride-rich and bakuchiol-rich fractions. Fatty acid profiling revealed linoleic acid (28.2%) and oleic acid (26.6%) as the predominant unsaturated fatty acids, while palmitic acid (23.2%) was the major saturated fatty acid. Bakuchiol identity was supported by GC–FID, GC–MS, FT-IR, and NMR analyses. Antioxidant activity was evaluated using the DPPH radical scavenging assay, with butylated hydroxytoluene (BHT) as the reference. Bakuchiol exhibited concentration-dependent activity, showing greater scavenging than BHT at 0.25–2.0 mM, whereas BHT was more active at higher concentrations. The preliminary IC₅₀ estimate for bakuchiol requires confirmation at lower concentrations. These findings highlight P. corylifolia seeds as potential sources of bakuchiol and triglyceride-rich fractions for further investigation in cosmetic and pharmaceutical applications.