A new diterpenoid with antispasmodic activity from Salvia cinnabarina.

From the leaf surface exudate of the aerial parts of Salvia cinnabarina a new secoisopimarane diterpenoid with a non-specific spasmolytic activity on histamine-, acetylcholine-, and barium chloride-induced contractions in the isolated guinea-pig ileum was obtained. The IC50 value obtained was comparable with that obtained for papaverine. The structure of 3,4-secoisopimara-4(18),7,15-triene-3-oic acid was established by 1D and 2D NMR spectroscopic techniques.