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

Abstract

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.