Preparative isolation and characterization of monoterpene isomers present in the citral-rich essential oil of Pectis brevipedunculata

In Brazil, many plant species are known as lemongrass due to the citric fragrance of their volatile compounds. Pectis brevipedunculata is a Brazilian ornamental aromatic grass with a ‘lemongrass odor’. To investigate this native Brazilian plant, fresh aerial parts were subjected to hydrodistillation (HD) and solid phase microextraction (SPME). The major compounds (>91.0%) separated by HD were the aldehydes neral and geranial. The chromatographic profile of volatile SPME fractions showed that monoterpenes were the major components, especially α-pinene and limonene. Countercurrent chromatography was used for the preparative isolation of citral (780 mg, >98.7% purity) and geraniol (8 mg, 86.0% purity). In addition, neral (7 mg, 87.5% purity) and geranial (12 mg, 91.0% purity) were purified by high-speed counter-current chromatography (HSCCC). This work demonstrates that P. brevipedunculata is a potential source of citral and HSCCC is a useful tool for separating essential oil components with high purity and mass recovery.