Diterpenoids from the flowers of Rhododendron molle.

Five new grayanane-type diterpenoids, rhodomolleins IX (1), X (2), XI (3), XII (4), and XIII (5), a new kalmane-type diterpenoid, rhodomollein XIV (6), and seven known diterpenoids, grayanotoxin II, rhodomolleins I and XIX, rhodojaponins II, III, and VI (7), and kalmanol, were isolated from the flowers of Rhododendron molle. The structures of 1-6 were elucidated by spectroscopic methods, including 1D and 2D NMR experiments.