Isolation and Characterization of Lupeol and Stigmasterol from Vernonia ambigua Kotschy & Peyr

Vernonia ambigua Kotschy & Peyr (Asteraceae) has been investigated for its phytochemical constituents, but reports describing isolated compounds remain limited. This study aimed to isolate and characterise lupeol and stigmasterol from the whole plant. Authenticated plant material (voucher GSUH553) was air-dried, powdered and extracted by methanol maceration. The resulting crude extract (109.1 g) was partitioned using n-hexane, ethyl acetate and n-butanol. A 10 g portion of the n-hexane fraction was separated by silica-gel column chromatography. Fractions were monitored by thin-layer chromatography, pooled according to their chromatographic profiles and further purified by preparative thin-layer chromatography and recrystallisation. Two white crystalline isolates, VA25 (10 mg) and VA30 (8 mg), were obtained. VA25 had an Rf value of 0.62 and a melting point of 214–215 °C, whereas VA30 had an Rf value of 0.46 and a melting point of 167–169 °C. Fourier-transform infrared spectroscopy and proton, carbon-13 and DEPT-135 nuclear magnetic resonance analyses were used for structural assessment. Comparison of the spectral characteristics with published data supported the identification of VA25 as lupeol and VA30 as stigmasterol. These findings document the isolation of two phytochemical constituents from the whole plant of V. ambigua. Biological activities of the isolated compounds were not assessed in this study.