5,10-seco-neo-clerodanes and neo-clerodanes from Salvia microphylla.

Two new 5,10-seco-neo-clerodanes, salvimicrophyllins A and B (1 and 2), and two new neo-clerodanes, salvimicrophyllins C and D (3 and 4), were isolated from the leaves and flowers of Salvia microphylla. The structures of these compounds were elucidated mainly by analysis of their NMR spectroscopic and mass spectrometric data. The relative configurations of the salvimicrophyllins were determined by analysis of NOESY spectra and ECD curves, and the relative configuration of compound 2 was confirmed by single-crystal X-ray diffraction crystallography.