Phenolic constituents of Ononis vaginalis roots.

The ether soluble fraction of the roots of Ononis vaginalis Vahl. Symb. afforded three new compounds: 3-hydroxy-4,9-dimethoxycoumestan, maginaldehyde [2-(4-hydroxy-2-methoxyphenyl)-5,6-dimethoxy-3-benzofuran-carboxaldehyde] and 5,7,4'-trihydroxy-4-styrylcoumarin. In addition, four known pterocarpans; 3,4,9-trimethoxypterocarpan, maackiain, medicarpin and trifolirhizin were also isolated. The styrylcoumarin derivative showed significant antiviral activity against Herpes simplex type 1 and weak cytotoxicity.