Abstract: The aims of this study were to isolate epimers of methyl genipin and to identify their structures.Preparative liquid chromatography was used for the separation.The structures of separated compounds were determined by NMR spectral analysis.Two new epimers were successfully isolated and were identified as R-methyl genipin and S-methyl genipin.This is the first report of the isolation of R,S-methyl genipin and the elucidation of their absolute configurations.The ¹H-NMR data of R,S-methyl genipin were also reported for the first time.

Key words: Fructus Gardeniae, geniposide, methyl genipin, epimer, structural identification