From Astragalus canadensis var. Mortonii and A. flexuosus var. flexuosus, two nitropropanoic acid glucosides were isolated: karakin and 1,6-di-(3-nitropropanoyl)-1-β-D-glucopyranose. A. flexuosus was also found to contain other nitro compounds including miserotoxin. Two new chromatographic methods were introduced for rapid identification of nitro-containing compounds contained in crude plant extracts. The first involves modification of the Griess-Ilosvay method to produce a spray reagent for visualization of nitro-containing compounds on TLC. The second uses high pressure liquid chromatography with UV detection for nitro-containing compounds separated on a micro-Porasil column.