The toxic constituent of Indigofera endecaphylla

Further proof is offered that the toxic constituent of creeping indigo is β-nitropropionic acid. This compound was synthesized and compared with the isolated material. Both compounds were toxic in the chick test, both had the same melting point, and both gave the same infrared absorption spectra. A sensitive chemical test for the quantitative analysis of this compound in plant material is discussed. This test is sufficiently sensitive so that individual plants may be tested for the presence of this toxic compound. A survey of the nitrogen compounds in creeping indigo revealed a high nitrite concentration. Nitrites were shown to be relatively toxic in the chick test and so may add to the toxicity of creeping indigo.