Three novel nortriterpenoids from Notochaete hamosa Benth. (Labiatae)

Three nortriterpenoids, notohamosin A (), B () and C () with novel skeleton, and eight known compounds were isolated from the ethanol extract of the whole plants of Notochaete hamosa Benth. (Labiatae). On the basis of spectral evidence including 1D, 2D NMR, IR and MS data, their structures were elucidated. The relative configurations of compounds , and were determined according to NOESY experiments.