Three new compounds from Isodon melissoides.

Reinvestigation of the aerial parts of Isodon melissoides has afforded two new ent-diterpenoids, melissoidesins V (1) and W (2), together with five known ones, glabcensin W (3), melissoidesin C (4), melissoidesin A (5), melissoidesin B (6) and melissoidesin D (7), one new ionone derivative 3alpha,4alpha-isopropyliden-beta-ionol (8), as well as three analogues, 3-hydroxy-4-oxo-beta-ionol (9), megastigma-7-en-3,5,6,9-tetraol (10) and blumenol A (11), and three phenolic compounds salicylic acid (12), syringic acid (13) and cirsiliol (14). The new structures were elucidated on the basis of spectroscopic techniques, especially the 2D-NMR spectral analysis.