Further labdane diterpenoids isolated from Leonurus persicus

Seven new labdane diterpenoids, leopersin G-L (1-4, 6-7) and 15-epi- leopersin J (5), and two known ones, 13-hydroxyballonigrinolide (8) and ballotenol (9), were isolated from the aerial parts of Leonurus persicus along with β-sitosterol and stigmasterol. The structure determinations were mainly based on 1D and 2D NMR spectra. The stereochemical configuration of ballotenol (9) was reestablished by 2D ROESY spectroscopy and by single- crystal X-ray diffraction analysis.