ISOLATION AND IDENTIFICATION OF Β-SITOSTEROL FROM ZYGOPHYLLUM FABAGO L. HERB USING SUBCRITICAL CO₂ EXTRACTION

β-Sitosterol is a bioactive phytosterol with recognized anti-inflammatory, hypocholesterolemic, and immunomodulatory properties. While Zygophyllum fabago L. is known to contain steroidal compounds, systematic studies on the isolation of pure β-sitosterol from this species are limited, particularly regarding the use of green extraction technologies and the achievement of high-purity yields for industrial applications. This study aimed to isolate and identify β-sitosterol from the herb of Z. fabago L. utilizing subcritical CO2 extraction as an environmentally sustainable and selective methodology for nonpolar compounds.

β-Sitosterol was isolated from the herb of Zygophyllum fabago L. using subcritical CO2 extraction (57-65 atm, 18-27 °C, 6 L/h). The crude extract was purified via vacuum liquid chromatography (VLC) on silica gel 60 and recrystallized from methanol, with purity monitored by TLC (UV 254/366 nm and H2SO4 visualization). Identification was performed using 1H and 13C NMR spectroscopy and the structure was confirmed by comparison with literature data.

The subcritical CO2 extraction yielded 20 g of crude extract (2.3% yield). The purification process resulted in 1.0 g of pure β-sitosterol, representing a 5% yield relative to the crude extract. TLC analysis showed a single characteristic spot, and NMR data definitively confirmed the structure, identifying key signals such as the C-3 hydroxyl group, the Δ5 double bond, and the characteristic branched aliphatic side chain.

These results demonstrate that Z. fabago L. is a high-yielding natural source of β-sitosterol. Furthermore, the study validates subcritical CO2 extraction as a highly effective and selective approach for the preparative isolation of phytosterols from plant matrices, offering significant advantages in terms of purity and environmental impact.