A hitherto unknown minor constituent of the seeds of Ammivisnaga Lam is converted under the influence of 5% alcoholic potassium hydroxide into a compound which seems to be a coumarin. Treatment with methyl-alcoholic alkali yields a substance C15H16O5, whereas treatment with ethyl-alcoholic alkali gives a substance C16H18O5. Dehydrating agents convert both optically active compounds into the same optically inactive dehydration product C14Hl2O4 (Substance A). The further investigations carried out with Substance A were: oxidation, after methylation, which yielded α-hydroxyisobutyric acid; fusion with potassium hydroxide, which gave phloroglucinol. On treatment with diluted caustic alkalies two definite products, C10H6O5, probably an acid, and C11H8O4, a ketone, were obtained.