New preparation of pure petroselinic acid from fennel oil (Foeniculum vulgare)

Pure petroselinic acid (cis‐6‐octadecenoic acid) has been isolated from fennel oil by acid soap crystallization at 4°C in methanol, followed by two urea segregations at room temperature and crystallization at −30°C in acetone. The purity control of petroselinic acid was effected by combined gas chromatography, and13C nuclear magnetic resonance. This petroselinic acid preparation was compared to other previous crystallization or enzymatic methods, showing that this method is both short (four steps) and easy to apply.