Isolation and structure of palstatin from the Amazon tree Hymeneae palustris

Bioassay (P388 lymphocytic leukemia cell line and human cancer cell lines) guided separation of an extract prepared from the leaves of Hymenaea palustris Ducke led to the isolation of six cancer cell growth inhibitory flavonoids (1-6). The structures were elucidated by HRMS and 1D and 2D NMR spectral analysis. The new flavonolignan 1 designated palstatin proved to be a methoxy structural modification of 5'-methoxyhydnocarpin-D (2). Flavones 1-4 inhibited growth of the pathogenic bacteria Enterococcus faecalis and/or Neisseria gonorrhoeae.