Polystachyne F, a 5,10-seco-neoclerodane from Salvia polystachya.

A new 5,10-seco-neoclerodane diterpene, polystachyne F (1), was isolated from the aerial parts of Salvia polystachya. Its structure was established on the basis of its spectroscopic properties and X-ray crystallographic analysis. Some correlations in the NOESY spectrum of 1 suggested the existence of a conformational equilibrium.