Antioxidative components of Psoralea corylifolia (Leguminosae)

Abstract A meroterpene and four flavonoids were isolated from the seeds of Psoralea corylifolia as antioxidative components. Their structures were elucidated by spectral data and identified as bakuchiol ( 1 ), bavachinin ( 2 ), bavachin ( 3 ), isobavachin ( 4 ) and isobavachalcone ( 5 ). In particular, meroterpene 1 and flavonoids 4 and 5 showed broad antioxidative activities in rat liver microsomes and mitochondria. They inhibited NADPH‐, ascorbate‐, t ‐BuOOH‐ and CCl 4 ‐induced lipid peroxidation in microsomes. They also prevented NADH‐dependent and ascorbate‐induced mitochondrial lipid peroxidation. Bakuchiol ( 1 ) was the most potent antioxidant in microsomes and the inhibition of oxygen consumption induced by lipid peroxidation was time‐dependent. Furthermore, bakuchiol ( 1 ) protected human red blood cells against oxidative haemolysis. These phenolic compounds in P. corylifolia were shown to be effective in protecting biological membranes against various oxidative stresses. Copyright © 2002 John Wiley & Sons, Ltd.