Antibacterial prenylflavone derivatives from Psoralea corylifolia, and their structure–activity relationship study

Three new prenylflavonoids, namely corylifols A–C (1–3), together with 13 known ones, were isolated from the seeds of Psoralea corylifolia. Their structures were elucidated by spectral methods including 1D and 2D NMR techniques. All the isolates were tested on antibacterial assays, and nine of them showed significant antibacterial activities against two pathogenic bacteria Staphylococcus aureus and S. epidermidis. The antibacterial structure–activity relationship of these prenylflavonoids (1–16) was also briefly discussed.