title: Profiling of dehydropyrrolizidine alkaloids and their N-oxides in herbarium-preserved specimens of amsinckia species using HPLC-esi(+)MS.
abstract: Species of the Amsinckia genus (Boraginaceae) are known to produce potentially hepato-, pneumo-, and/or genotoxic dehydropyrrolizidine alkaloids. However, the taxonomic differentiation of Amsinckia species can be very subtle and there seems to be marked differences in toxicity toward grazing livestock. Methanol extracts of mass-limited leaf samples from herbarium specimens (collected from 1899 to 2013) of 10 Amsinckia species and one variety were analyzed using HPLC-esi(+)MS and MS/MS for the presence of potentially toxic dehydropyrrolizidine alkaloids and/or their N-oxides. Dehydropyrrolizidine alkaloids were detected in all specimens examined ranging from about 1 to 4000 μg/g of plant. Usually occurring mainly as their N-oxides, the predominant alkaloids were the epimeric lycopsamine and intermedine. Also sometimes observed in higher concentrations were the 3'- and 7-acetyl derivatives of lycopsamine/intermedine and their N-oxides. Within a designated species, an inconsistent profile was often observed that may be due to natural variation, taxonomic misassignment, or nonuniform degradation due to plant collection and storage differences.
authors.affiliation: Poisonous Plant Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture , 1150 East 1400 North, Logan, Utah 84341, United States.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Colegate
authors.forename: Stanley L
authors.initials: SL
authors.lastname: Welsh
authors.forename: Dale R
authors.initials: DR
authors.lastname: Gardner
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Betz
authors.forename: Kip E
authors.initials: KE
authors.lastname: Panter
mesh_terms: D029682:Amsinckia / Q000737:chemistry* / Q000145:classification; D002851:Chromatography, High Pressure Liquid; D018515:Plant Leaves / Q000737:chemistry; D011763:Pyrrolizidine Alkaloids / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D011763:Pyrrolizidine Alkaloids