Isolation of Four Major Compounds of γ-Oryzanol from Rice Bran Oil by Ionic Liquids Modified High-Speed Countercurrent Chromatography and Antimicrobial Activity and Neuroprotective Effect of Cycloartenyl Ferulate In Vitro

This study presents an effective high-speed countercurrent chromatography method of two-phase solvent system combined with ionic liquids for the isolation and purification of four major compounds of γ-oryzanol from rice bran oil. The conditions of high-speed countercurrent chromatography, including solvent systems and the content of ionic liquids, were optimized to improve separation efficiency. The optimal solvent system was n-hexane–dichloromethane–acetonitrile–[C 4 mim][PF 6 ] at a volume ratio of (10:1:10:0.15, v/v). Adding a small amount of ionic liquids significantly improved the separation efficiency. Four compounds of γ-oryzanol, cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, campesteryl ferulate, and sitosteryl ferulate were successfully purified in one run from rice bran oil with the purities of 95.25%, 92.48%, 92.47%, and 93.43%, respectively. The result of bioassay showed that rice bran oil and separated individual cycloartenyl ferulate could significantly inhibit mycelium growth of crop diseases Rhizoctonia solani and Fusarium graminerum , the bioactivity of cycloartenyl was higher than that of the rice bran oil. The cellular antioxidant activity experimental result indicted that cycloartenyl ferulate could alleviate H 2 O 2 -induced oxidative stress.