Two New Diterpenoids and other Constituents from Isodon Nervosus

Two new ent‐kaurane diterpenoids, 15β‐hydroxy‐6,7‐seco‐6,11β:6,20‐diepoxy‐1α,7‐olide‐ent‐kaur‐16‐ene ( 1 ), 11α,15α‐dihydroxy‐6β‐methoxy‐6,7‐seco‐6,20‐epoxy‐1α,7‐olide‐ent‐kaur‐16‐ene ( 2 ), together with four known diterpenoids, nodosin ( 3 ), isodocarpin ( 4 ), odonicin ( 5 ) and maoyecrystal F ( 6 ) were isolated from the aerial parts of Isodon nervosus. The structures of the new compounds were elucidated on the basis of their spectral evidence, especially on 2D NMR.