Anti-diabetic compounds from the seeds of Psoralea corylifolia.

A new aurone named (2Z)-2-[(4′-hydroxyphenyl) methylene]-6-hydroxy-7-prenyl-3(2H)-benzofurane (1), two new flavonoids named (2S)-7-methoxy-6-(2-hydroxy-3-methylbut-3-en-1-yl)-2-(4-hydroxyphenyl)chroman-4-one (2), (2S)-4′-hydroxyl-7-hydroxymethylene-6-(2″,3″-epoxy-3″-methylbutyl)flavanone (3), and a new coumestan named bavacoumestan E (4), together with eleven known compounds (5–15), were isolated from the seeds of Psoralea corylifolia. The chemical structures were elucidated by spectroscopic and physico-chemical analyses. All isolates were evaluated for in vitro inhibitory activity against DGAT, PTP1B and α-glucosidase. Compounds 1, 2 and 3 showed potential inhibitory activities on DGAT1 with IC50 values of 35.2 ± 1.3, 51.3 ± 1.1 and 43.4 ± 0.7 μM, respectively. Compounds 6 and 8 displayed the significant inhibitory activities on α-glucosidase with IC50 value of 28.0 and 23.0 μM, respectively.