Abstract: Aim To investigate the structure of mogroside Iva isolated from traditional Chinese medicine fructus mo-mordicae [fruits of Siraitia grosvenori (Swingle) C. Jeffery] and summarize the NMR characteristics of the structure. Methods Common extraction, separation and purification methods were used. Various NMR techniques including ¹H NMR,¹³C NMR, DEPT, ¹H-¹H COSY, HSQC, HMBC, NOESY and molecular model simulated by computer were used to elucidatethe structure. Results ¹H and ¹³C NMR signals of mogroside IVa were assigned, and spectroscopic basis was obtained for identification of such type of compounds. Conclusion 1D and 2D NMR techniques including ¹H-¹H COSY, HSQC, HM-BC, NOESY spectra are powerful tools for structure analysis. The structure determined by NMR methods is identical with energy minimized conformation simulated by computer.

Key words: fructus momordicae, fructus momordicae, mogroside IVa, mogroside IVa, triterpenoid saponin, triterpenoid saponin, NMR spectrum, NMR spectrum, assignment, assignment