| Abstract: | From the MeOH extract of the aerial parts of Swertia mileensis, four new secoiridoid glycosides were isolated, 4′‐O‐(E)‐caffeoyl]swertiamarin ( 1 ), 4′‐O‐(Z)‐coumaroyl]swertiamarin ( 7 ), 6′‐O‐(E)‐coumaroyl]swertiamarin ( 8 ), and 6′‐O‐(Z)‐coumaroyl]swertiamarin ( 9 ), together with five known compounds. Their structures were elucidated by NMR spectroscopy and tandem mass spectrometry. Detailed HPLC/MS analyses and MS/MS fragmentation pathways are discussed for the identification of the swertiamarin‐derived (E)/(Z) isomers 6 / 7 and 8 / 9 . |
