The prenylated isoflavone structures, identified by spectroscopic analysis, were 8-Prenylluteone ( 1), auriculatin ( 2), erysenegalensein O ( 3), erysenegalensein D ( 4), erysenegalensein N ( 5), derrone ( 6), alpinumisoflavone ( 7), and 6,8-diprenylgenistein ( 8). The constituents showed dose-dependent inhibitory activities on HIV-1 PR with IC (50) values from 0.5 to 30.0 muM.