title: Selective ultrasound-enhanced enzymatic hydrolysis of oleuropein to its aglycon in olive (Olea europaea L.) leaf extracts.
abstract: Hydrolysis of oleuropein, the main phenol in olive (Olea europaea L.) leaf extracts, to oleuropein aglycon and other subsequent products in the hydrolytic pathway can be catalyzed by different enzymes. Three of the most used hydrolases were assayed to catalyze the process, and β-glucosidase from Aspergillus niger was selected. Acceleration of the enzymatic hydrolysis by ultrasound (US) was studied using a Box-Behnken design (duty cycle, amplitude, cycle time) and an oleuropein standard, and the optimum US conditions for achieving maximum yield of oleuropein aglycon were 0.5s/s duty cycle, 50% amplitude and 45s cycle. The method was applied to obtain oleuropein aglycon from commercial and laboratory extracts from olive leaves, which may have a pharmacological use as deduced by its healthy properties. The kinetics of the US-assisted enzymatic hydrolysis was monitored by analysis of the target compounds using liquid chromatography-tandem mass spectrometry.
authors.affiliation: Department of Analytical Chemistry, Annex Marie Curie Building, Campus of Rabanales, University of Córdoba, 14071 Córdoba, Spain; ceiA3 Agroalimentary Excellence Campus, University of Córdoba, 14071 Córdoba, Spain; Maimónides Institute of Biomedical Research (IMIBIC), Reina Sofía University Hospital, 14004 Córdoba, Spain.
authors.forename: María Del Mar
authors.initials: MD
authors.lastname: Delgado-Povedano
authors.affiliation: Department of Analytical Chemistry, Annex Marie Curie Building, Campus of Rabanales, University of Córdoba, 14071 Córdoba, Spain; ceiA3 Agroalimentary Excellence Campus, University of Córdoba, 14071 Córdoba, Spain; Maimónides Institute of Biomedical Research (IMIBIC), Reina Sofía University Hospital, 14004 Córdoba, Spain. Electronic address: q72prcaf@uco.es.
authors.forename: Feliciano
authors.initials: F
authors.lastname: Priego-Capote
authors.affiliation: Department of Analytical Chemistry, Annex Marie Curie Building, Campus of Rabanales, University of Córdoba, 14071 Córdoba, Spain; ceiA3 Agroalimentary Excellence Campus, University of Córdoba, 14071 Córdoba, Spain; Maimónides Institute of Biomedical Research (IMIBIC), Reina Sofía University Hospital, 14004 Córdoba, Spain. Electronic address: qa1lucam@uco.es.
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Luque de Castro
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology; D002853:Chromatography, Liquid; D006868:Hydrolysis; D057888:Iridoid Glucosides; D039823:Iridoids / Q000737:chemistry*; D031658:Olea / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D014465:Ultrasonics; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D057888:Iridoid Glucosides; D039823:Iridoids; D010936:Plant Extracts; C002769:oleuropein; D001617:beta-Glucosidase
keywords: Enzymatic hydrolysis; Glucosidase; Olea europaea leaf extract; Oleuropein; Oleuropein (PubChem CID: 53297357); Oleuropein aglycon; Oleuropein aglycon (PubChem CID: 56842347); Ultrasound