Dynamic ultrasound-assisted extraction of oleuropein and related biophenols from olive leaves

• Published in: Journal of Chromatography A Vol. 1108; no. 1; pp. 76 - 82
• Main Authors: Japón-Luján, R., Luque-Rodríguez, J.M., Luque de Castro, M.D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 03-03-2006; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Biophenols; Chemical constitution; Chromatography, High Pressure Liquid; Dynamic ultrasound-assisted extraction; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry; Iridoids; OBPs; Olea - chemistry; Oleuropein; Olive leaves; Phenols - isolation & purification; Plant Leaves - chemistry; Polyphenols; Pyrans - isolation & purification; Reproducibility of Results; Ultrasonics; Polyphenols; OBPs; Dynamic ultrasound-assisted extraction; Oleuropein; Biophenols; Olive leaves; Iridoid; Chemical analysis; Olea europaea; HPLC chromatography; Solvent extraction; Flavonoid; Polyphenol; Ultrasound assisted extraction; Sample preparation; Dicotyledones; Angiospermae; Glycoside; Ultrasound; Quantitative analysis; Terpenoid; Oleaceae; Aldose; Dynamic ultrasound-assisted extraction: Polyphenols: Olive leaves: Biophenols; Glucoside; Oleuropein: OBPs; Plant leaf; Operating conditions; Ultraviolet detector; Plant origin; Flavone derivatives; Monoterpene; Spermatophyta; Oil plant (vegetal)
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2005.12.106

A continuous approach for the ultrasound-assisted extraction of olive biophenols (OBPs) from olive leaves is proposed. Multivariate methodology was used to carry out a detailed optimisation of extraction. Under the optimal working conditions, complete extraction of the target analytes (namely, oleuropein, verbacoside, apigenin-7-glucoside and luteolin-7-glucoside with LODs 11.04, 2.68, 1.49 and 3.91
mg/kg, respectively) was achieved in 25
min. The extract was injected into a chromatograph–photodiode array detector assembly (HPLC–DAD) for individual separation–quantification. No clean-up or preconcentration steps were required. Gas chromatography–mass spectrometry (without derivatization of the analytes) was used to identify OBPs at concentrations below the LODs obtained by HPLC–DAD. The efficacy of ethanol–water mixtures to extract OBPs from olive leaves has been demonstrated and compared with that of a conventional method which requires 24
h for complete extraction; so these mixtures can substitute toxic extractants used to date.