Three new norlignans from Curculigo capitulata

From the ethanolic extract of the rhizomes of Curculigo capitulata have been isolated, and structurally elucidated by spectral evidences and chemical methods, three new norlignans, capituloside (1), a mixture of curculigenin (2) and isocurculigenin (3), along with four known compounds (4-7), a mixture of 1-O-methylcurculigine (4) and 1-O-methylisocurculigine (5) and a mixture of curculigine (6) and isocurculigine (7).