Govanosides C-F, unprecedented steroidal saponins with rare sugars from rhizomes of Trillium govanianum and their antagonistic effects on acetylcholinesterase

Four previously undescribed steroidal saponins named govanosides C-F (1-4) and nine known compounds (5-13) were isolated from the rhizomes of Trillium govanianum Wall. ex D.Don. Govanosides C-E contained a rare sugar moiety i.e., 6-deoxy allose, while govanoside F has acetylated rhamnose moiety in its glycan part. Also, this is the first report on the isolation of feruloyl sucrose derivatives (11-12) and (E)-4-hydroxy-dodec-2-enedioic acid (13) from the Trillium genus. The structure of isolated compounds was deduced using 1D and 2D NMR, HRESIMS, LC-MS/MS, GC-MS, and saccharide linkage analysis. Steroidal scaffold isolates (1-10) were evaluated for their antagonistic effects on acetylcholinesterase inhibitory activity. Govanoside C (1) significantly inhibited acetylcholinesterase (IC50: 2.38 & mu;M). Molecular docking experiments have also been performed to depict the molecule's interaction and binding free energy with acetylcholinesterase.

Automated summary

Four new compounds were isolated from the rhizomes of Trillium govanianum, including some rare sugar moieties. This is also the first report on the isolation of certain compounds from the Trillium genus, as well as feruloyl sucrose derivatives and (E)-4-hydroxy-dodec-2-enedioic acid. One of the compounds showed inhibitory activity against acetylcholinesterase.