Two pairs of enantiomeric propylated flavonoids and a new lignan from the aerial parts of Abrus precatorius.

Two pairs of novel enantiomeric flavonoids (1a, 1b and 2a, 2b), along with one new lignan (3), were isolated from the aerial parts of Abrus precatorius. All of these enantiomeric flavonoids featured an unprecedented propylated flavonoid skeleton representing a new family of flavonoid, and the new lignan was found to have an attractive arachidate ester side chain. Their structures were extensively elucidated by means of detailed NMR and mass spectroscopic analysis. Moreover, biological evaluation of antibacterial activity for these compounds against Bacillus cereus and Escherichia coli were conducted.