Two new steroidal alkaloids from the aerial part of <i>Fritillaria walujewii</i>

Phytochemical investigation on the aerial part of <i>Fritillaria walujewii</i> Regel resulted in the isolation of two new steroidal alkaloids, named as walujewine F (<b>1</b>) and G (<b>2</b>), and five previously reported compounds <b>3</b>-<b>7</b>. Structural elucidation of compounds <b>1</b>-<b>7</b> was achieved by employing various spectroscopic techniques. The cholinesterase inhibitory potential of all the compounds was systematically evaluated. Compound <b>1</b> exhibited moderate AChE inhibition with the IC₅₀ value of 70.37 μM, while compound <b>2</b> demonstrated obvious dual AChE and BChE inhibitory effects, with the IC₅₀ values of 91.69 μM and 67.12 μM, respectively, but lower than the positive control galantamine (IC₅₀ values of 2.80 μM for AChE and 21.85 μM for BChE).