Sesquiterpenoids from the herb of Leonurus japonicus.

Two new sesquiterpenoids, (-)-(1S*,2S*,3R*)-3-ethoxycupar-5-ene-1,2-diol (1) and (-)-(1S*,4S*,9S*)-1,9-epoxybisabola-2,10-diene-4-ol (2), along with six known compounds 3-8, were isolated from the EtOH extract of the herb of Leonurus japonicus. Their structures were elucidated by physical and spectroscopic analysis. In the in vitro assays, compounds 7 and 8 showed obvious antibacterial activity against several bacteria strains, while compound 3 significantly inhibited abnormal increase of platelet aggregation induced by ADP.