Three novel eremophilanolides from Ligularia virgaurea spp. oligocephala

From the alcoholic extract of the whole plant of Ligularia virgaurea spp. oligocephala, three novel eremophilane sesquiterpene lactones, 6alpha,10alpha-dihydroxy-1-oxoeremophila-7(11), 8(9)-dien-8, 12-olide, 6beta, 10alpha-dihydroxy-1-oxoeremophila-7 (11), 8 (9)-dien-8, 12-olide and 10alpha-hydroxy-1-oxoeremophila-7(11), 8(9)-dien-8, 12-olide were isolated. Their structures were elucidated by various spectroscopic methods including intensive 2D NMR techniques (COSY, HMQC, HMBC and H-1-H-1 NOESY) and HR-MS.