Comparison of MAHD with UAE and Hydrodistillation for the Analysis of Volatile Oil From Four Parts of Perilla frutescens Cultivated in Southern China

Abstract

Three different isolation techniques, specifically microwave-assisted hydrodistillation (MAHD), ultrasound-assisted extraction (UAE), and conventional hydrodistillation (HD) were employed to obtain essential oils from whole plants, leaves, roots, and stems of Perilla frutescens. The essential oils were analyzed using gas chromatography with flame ionization detection and gas chromatography with mass spectrometry. Variations in chemical composition were observed; these were attributed to differences in plant organs. Variations in the percentages of the main constituents of the oils extracted based on plant organ were irregular and affected the quantity and composition of the oils. Oil yields were affected by the method of extraction and extraction organ variation. The maximum volume of oil was extracted from leaves via MAHD and the minimum was extracted from roots via UAE. Oil yields ranged from 0.05% to 0.53%. The contents of essential oil varied significantly with the plant organ. In the essential oils of the plant parts studied were showed a predominance of oxygenated monoterpenes. Variation of extraction methods and organs may influence the oil components either qualitatively or quantitatively.

Keywords:

• Essential oil
• GC-MS
• MAHD
• Organs
• Perilla frutescens
• UAE

Acknowledgments

This research was supported by the National Natural Science Foundation of China (No. 21164001), the Science and Technology Planning Project of Guangdong Province of China (No. 2011B020314011), and the Natural Science Foundation of Guangdong Province of China (No. S2011010004004).

Notes

^a RI, retention indices relative to C₈–C₂₂ n–alkanes on the DB–5 column.

^b –, absence.

^c Others: alkenes and esters.