A phytochemical investigation of the roots of Krameria tomentosa A. St. -Hil. led to the isolation of five neolignans, two of them with novel structures [1,1'-(E)-propenyl-4-methoxy3,4'-oxyneolignan (ottomentosa) and 2-(2'-hydroxy-4',6'-dimethoxyphenyl)benzofuran5-carboxylic acid (sobraline)] and three known compounds [eupomatenoid 6, dihydrocarinatidin and 2-(2',4'-dihydroxyphenyl)-5-(E)-propenylbenzofuran]. The structural characterization of the compounds isolated was established based on infrared spectroscopy, mass spectrometry, one-and two-dimensional nuclear magnetic resonance, along with comparison with spectral data described in the literature.
Krameria tomentosa; Krameriaceae; neolignans; ottomentosa; sobraline