In vitroBACE-1 Inhibitory Phenolic Components from the Seeds ofPsoralea corylifolia

A new isoflavone, neocorylin (1) was isolated from the seeds extract of Psoralea corylifolia L. (Fabaceae), together with eight known constituents (2 – 9), i. e., bakuchiol (2), psoralen (3), bavachromene (4), isobavachromene (5), bavachalcone (6), isobavachalcone (7), 7,8-dihydro-8-(4-hydrophenyl)-2,2-dimethyl-2H,6H-[1,2-b:5,4-b′]dipyran-6-one (8), and bavachinin (9). The structure of the new isoflavone 1 was elucidated as 7-hydroxy-3-[2-methyl-2-(4-methylpenten-3-yl)-2H-chromen-6-yl]-4H-chromen-4-one by spectroscopic analyses. Neocorylin (1) as well as related compounds 2, 4 – 6, 8 and 9 exhibited a significant inhibitory effect on baculovirus-expressed BACE-1 in vitro.