Twelve new terpenoids (1–12) were
isolated from the stems of Fissistigma polyanthoides, an anti-inflammatory medicinal plant traditionally used in Vietnam.
Most of them (1–9) possess a sesquiterpenoid
backbone (e.g., guaiane, germacrane, and cadinane) connected to a
2′-O-trans-cinnamoyl)-β-d-glucopyranose moiety, which is rare in Nature. Among them,
compounds 4 (5/8-fused ring) and 6 (spiran
[4,5] ring) represent uncommonly rearranged sesquiterpenoids. Compounds 10–12 are a novel monoterpene and two
megastigmane derivatives, respectively. The individual structures
were elucidated by combining NMR and MS data, and their configuration
was established in NOESY and ECD experiments. Compounds 1–9 were also examined for their potential to
interact with nuclear factor-kappa B activator protein 1 (NF-κB/AP-1)
signaling by using the myelomonocytic reporter cell line THP-1Blue-CD14.
Compounds 1–5 showed dose-dependent
inhibitory effects [IC50 13.7 μM (1)
to 49.0 μM (5)] on lipopolysaccharide-stimulated
cells. However, compounds 1 to 4 also negatively
affected cell viability in the same concentration range, while compound 5 was less potently cytotoxic.