A Novel Antibacterial Diterpene fromPremna schimperi

Abstract
A novel diterpene, (5R,8R,9S,10R)-12-oxo-ent-3,13(16)-clerodien-15-oic acid, has been obtained from the leaves of Premna schimperi (Verbenaceae) using an anti-microbial bioassay-guided isolation procedure. The diterpene was identified on the basis of spectroscopic data and is active against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis in the concentration range 20-25 µg ml-1.