Ultrafiltration as alternative purification procedure for the characterization of low and high molecular-mass phenolics from almond skins.
A combination of sample preparation (ultrafiltration) and analysis techniques is proposed for the characterization of complex phenolic mixtures such as extracts from almond (Prunus dulcis (Mill.) D.A. Webb) skins. LC/ESI-MS analysis of the permeates obtained after ultrafiltration on semipermeable membranes (low molecular-mass phenolic fractions) allowed the identification of several benzoic acids and aldehydes, flavan-3-ol monomers and oligomers, and flavonol and flavanone glycosides in almond skins. MALDI-TOF and ESI-MS/MS analysis of the diafiltered concentrates (high molecular-mass phenolic fractions) demonstrated the presence of proanthocyanidin oligomers up to decamers, composed of (epi)afzelechin, (epi)catechin and (epi)gallocatechin units linked by C-C bonds (type B) and by both C-C and C-O bonds (type A). This analytical protocol can be of utility in the study of low and high molecular-mass phenolic compounds in natural products.
Prodanov
Marin
M
Departamento de Agroalimentación, IMIDRA, Ctra. A-2, km 38.200, Finca El Encín, E-28800 Alcalá de Henares, Madrid, Spain.
Garrido
Ignacio
I
Vacas
Visitación
V
Lebrón-Aguilar
Rosa
R
Dueñas
Montserrat
M
Gómez-Cordovés
Carmen
C
Bartolomé
Begoña
B
D002853:Chromatography, Liquid; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D062385:Hydroxybenzoates / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification*; D008970:Molecular Weight; D027861:Prunus / Q000033:anatomy & histology* / Q000737:chemistry* / Q000254:growth & development; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry; D014462:Ultrafiltration / Q000379:methods*
D062385:Hydroxybenzoates; C017616:phenolic acid