A mass-spectrometric study of arnifolin, a new sesquiterpene lactone from Arnica montana and A. foliosa

Summary The mass spectra of arnifolin and D]arnifolin have been obtained, and the fragmentation of arnifolin under the action of electron impact has been studied.A scheme of the fragmentation of arnifolin explaining the main peaks in its mass spectrum has been put forward. The mass spectrum agrees well with the structure established for this substance.All-Union Scientific-Research Institute of Medicinal Plants. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 587–590, September–October, 1971.