A clerodane diterpene with antibacterial activity from Ajuga lupulina.

The structure of a new diterpene, C30H46O11, with antibacterial activity against Pseudomonas aeruginose and Escherichia coli, isolated from the fresh whole plants of Ajuga lupulina (Labiatae) was established to be 2 beta-hydroxy-2-methylbutanoyl-3 alpha-lupulin (3-deoxy-14,15-dihydro-2-hydroxy-15-methoxycaryoptinol 2-methylbutanoate), by means of X-ray crystallographic analysis. The present study confirms that the two six-membered rings are in ideal chair conformations.