Alkaloids of some Mongolian ranunculaceae species: Detailed H-1 and C-13-NMR studies of denudatine and lepenine

We have investigated the alkloidal constituents of Aconitum barbatum, A. ku snezoffii,A. volubile, and Delphinium cheilanthum collected in Mongolia. Se ven norditerpenoid and seven diterpenoid alkaloids were isolated and identi fied from these plants. H-1 Decoupled C-13, 2D H-1 phase sensitive COSY, PO ESY, TOCSY, HMQC-TOCSY and HMBC NMR spectral studies were carried out on de nudatine and lepenine to make definitive assignments for the carbon atoms o f these alkaloids.