title: High-performance liquid chromatography-diode array detection-electrospray ionization multi-stage mass spectrometric screening of an insect/plant system: the case of Spodoptera littoralis/Lycopersicon esculentum phenolics and alkaloids.
abstract: High-performance liquid chromatography-diode array detection-electrospray ionization multi-stage mass spectrometry (HPLC-DAD-ESI-MS(n)) is considered to be a very valuable tool for the characterization of compounds found in trace amounts in natural matrices, as their previous isolation and clean-up steps can be avoided. Micro-scale separation increases the potential of this analytical technique, allowing the determination of compounds in reduced samples. Spodoptera littoralis represents a major challenge to Solanaceae plants, as it is one of the most deleterious pests. The S. littoralis/Lycopersicon esculentum system was studied for the first time concerning glycoalkaloids and phenolics. Using HPLC-DAD-ESI-MS(n) we were able to characterize 15 phenolic compounds in L. esculentum leaves. Nine of them are reported for the first time. Some differences were found between leaves of cerasiforme and 'Bull's heart' varieties. However, in the materials of S. littoralis (larvae, adults, exuviae and excrements) reared in both L. esculentum leaves no phenolics were identified. α-Tomatine was the main glycoalkaloid in the host plant. The glycoalkaloid composition of the different S. littoralis materials was distinct, with α-tomatine and dehydrotomatine being the main detected compounds in larvae and excrements. These results add knowledge to the ecological interaction in this insect/plant duo, for which it is hard to obtain considerable sample amounts.
authors.affiliation: CEBAS (CSIC) Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, P.O. Box 164, 30100 Campus University Espinardo, Murcia, Spain. federico@cebas.csic.es
authors.forename: Federico
authors.initials: F
authors.lastname: Ferreres
authors.forename: Marcos
authors.initials: M
authors.lastname: Taveira
authors.forename: Angel
authors.initials: A
authors.lastname: Gil-Izquierdo
authors.forename: Luísa
authors.initials: L
authors.lastname: Oliveira
authors.forename: Tânia
authors.initials: T
authors.lastname: Teixeira
authors.forename: Patrícia
authors.initials: P
authors.lastname: Valentão
authors.forename: Nelson
authors.initials: N
authors.lastname: Simões
authors.forename: Paula B
authors.initials: PB
authors.lastname: Andrade
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification*; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006790:Host-Parasite Interactions; D018551:Solanum lycopersicum / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D018411:Spodoptera / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D010636:Phenols