Phenylnaphthalene compounds from the subterranean part of Vitex rotundifolia and their antibacterial activity against methicillin-resistant Staphylococcus aureus.

A careful investigation of the subterranean part of Vitex rotundifolia has shown that this plant contains five novel lignans having a 1-phenylnaphthalene-type skeleton together with four known lignans. These structures were elucidated on the basis of spectroscopic data. Furthermore, some of the isolated compounds showed antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA).