title: Comprehensive characterization of Annonaceous acetogenins within a complex extract by HPLC-ESI-LTQ-Orbitrap® using post-column lithium infusion.
abstract: Annonaceous acetogenins (AAGs) are a homogenous class of polyketides proposed as environmental neurotoxins. Previous dereplication studies of AAGs were limited by the use of low-resolution mass spectrometers. Only poor information in terms of structures was provided due to the limited fragmentation of protonated or sodium cationized species. An innovative approach, using reversed-phase high-performance liquid chromatography coupled to a hybrid linear ion trap/orbitrap mass spectrometer (LTQ-Orbitrap®), was therefore performed. Sensitivity was enhanced by post-column infusion of lithium, since AAGs have a high affinity for this cation. High level of structural information was obtained from low-energy-collision-induced dissociation fragmentation experiments of lithium-cationized AAGs ([M + Li](+) ions) as demonstrated with purified standards. The method was then applied to a total ethyl-acetate extract prepared from commercial soursop nectar (Annona muricata L.). The sensitivity, mass accuracy and specific fragmentation patterns proved to be particularly useful for characterization of the AAGs. Typical structural identification procedure and unexpected observations for specific structural types are illustrated, with major and minor compounds.
authors.affiliation: Laboratoire de Pharmacognosie, CNRS UMR 8076 BioCIS, Labex LERMIT, Faculté de Pharmacie, Université Paris-Sud, Châtenay-Malabry, France.
authors.forename: Jessica
authors.initials: J
authors.lastname: Le Ven
authors.forename: Isabelle
authors.initials: I
authors.lastname: Schmitz-Afonso
authors.forename: Guy
authors.initials: G
authors.lastname: Lewin
authors.forename: Olivier
authors.initials: O
authors.lastname: Laprévote
authors.forename: Alain
authors.initials: A
authors.lastname: Brunelle
authors.forename: David
authors.initials: D
authors.lastname: Touboul
authors.forename: Pierre
authors.initials: P
authors.lastname: Champy
mesh_terms: D000085:Acetates / Q000737:chemistry; D054378:Acetogenins / Q000032:analysis* / Q000737:chemistry*; D031041:Annona / Q000737:chemistry; D002412:Cations / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D056148:Chromatography, Reverse-Phase / Q000379:methods; D008094:Lithium / Q000737:chemistry*; D008958:Models, Molecular; D010936:Plant Extracts / Q000737:chemistry*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D000085:Acetates; D054378:Acetogenins; D002412:Cations; D010936:Plant Extracts; C007650:ethyl acetate; D008094:Lithium