Abstract
The essential oil from aerial parts of Psoralea pubescence (Miq.) Standl (Leguminoseae) was analyzed by gas chromatography (GC) and GC/mass spectroscopy systems. The major components identified were psoralen (24.8%), bakuchiol (21.3%), beta-caryophyllene (8.5%), germacrene D (6.8%), and alpha-humulene (4.6%). The major volatiles released by beta-glucosidase treatment of the aqueous plant residue were delta-pinene (28.3%), germacrene D (13.6%), and tricyclene (10.2%). The oil showed significant antibacterial activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa, while the beta-glucosidase-liberated fraction was inactive.