3-Nitropropionic acid and 3-nitro-1-propanol in species of Astragalus

Abstract

Leaves of nitro-bearing species of Astragalus collected from North American and European herbaria were analyzed for types of toxic aliphatic nitro compounds. The nitro compounds were extracted and hydrolized to 3-nitropropionic acid (3-NPA) or 3-nitro-1-propanol (3-NPOH) and identified by thin-layer chromatography. Species of Astragalus were chemotaxonomically related within taxonomic sections relative to synthesis of 3-NPA or 3-NPOH. All species of Astragalus in 19 Old World and 21 North American taxonomic sections synthesized nitro compounds that yielded 3-NPA upon hydrolysis while 3-NPOH was found upon hydrolysis in species of 5 Old World and 10 North American taxonomic sections. Therefore, one could predict the presence of 3-NPA or 3-NPOH in species within entire taxonomic sections based on the analysis of one or two species within a section. South American species yielded predominately 3-NPOH. These data are useful for taxonomic classification of Astragalus, for preventing international exchange of germplasm of poisonous species of Astragalus, and for diagnostic purposes in livestock poisoning.