Eight new γ-lactam alkaloids from the roots of the Hemerocallis minor Mill

Eight new γ-lactam alkaloids, hemerominors A-H (1-8), including two pair of epimers (1-4), together with six known compounds (9-14) were isolated from the roots of Hemerocallis minor Mill. The structures of 1-8 were established on the basis of extensive NMR studies and HR-MS measurements as well as comparison with literature data. The absolute configurations of 1-8 were determined by CD spectral analysis and modified Mosher's method. All of compounds were evaluated for their inhibitory effects against LPS-induced NO production in RAW264.7 macrophages. Among them, compound 13 exhibited moderate inhibitory activity against NO production and with IC₅₀ value of 18.0 μM.