Inhibitors Of HIF-1 And NF-κB Activation From Psoralea Corylifolia

The CHCl₃-soluble fraction from a methanolic extract of Psoralea corylifolia L. was found to significantly inhibit HIF-1 activity in an in vitro assay (78% inhibition at 4 μg/ml). Bioassay guided fractionation led to the isolation of two active compounds bakuchiol (28) and 12,13-dihydro-12,13-epoxybakuchiol (35) with IC₅₀ values of 4.7 μM and 44 μM respectively. In addition, five new compounds. (12'R)-bisbakuchiol (31). bisbuguzhi A (32), bisbuguzhi B (33), bisbuguzhi C (34) and 12,13-dihydroxybakuchiol (36). were isolated and their chemical structures were elucidated on the basis of spectruscopic studies. 4-acethyl-bakuchiol (28a) (IC₅₀ 4.8 μM) was a product of bakuchiol (28) that got through dissimilarly reaction.Among these compounds, only bakuchiol (28) exhibited inhibition of NF-κB activity with IC₅₀ values of 2.3 μM.