Anti-inflammatory lindenane-type sesquiterpenoid homo-/heterodimers from Chloranthus holostegius: Isolation, structural elucidation, and regulation of NF-κB/JAK pathways

Chloranthus holostegius , a perennial herbaceous plant of the family Chloranthaceae, is predominantly distributed in southern China and exhibits significant value in both horticultural and medicinal applications. In this study, nine previously undescribed lindenane-type sesquiterpenoid homo/heterodimers with diverse skeletons, designated as chlorholidenes A−I ( 1 – 9 ), including two novel naphthalene-fused norlindenane sesquiterpenoid dimers ( 1 – 2 ), two lindenane-type sesquiterpenoid dimers with naphthalene skeleton and 18-membered macrocycle ( 3 – 4 ), a 8,9- seco lindenane-type sesquiterpenoid dimer with an 18-membered macrocycle ( 5 ), a 2,3- seco lindenane-type dimer with [6 + 6] cycloaddition-formed 12-membered ring ( 6 ), an eudesmane-lindenane heterodimer ( 7 ), an lindenane-type sesquiterpenoid dimer with an oxaspiro [4.5]decane skeleton ( 8 ), and a classical lindenane dimer ( 9 ), together with two known acorane-lindenane heterodimers ( 10 – 11 ), were isolated from C. holostegius . Their structures were elucidated using 1D/2D NMR, HRESIMS, and ECD calculations. In vitro anti-inflammatory assays showed compounds 3 , 4 , and 11 exhibited significant inhibition of LPS-induced NO release in RAW 264.7 cells (IC₅₀: 12.14–16.13 μM), outperforming dexamethasone (IC₅₀ = 18.43 ± 3.17 μM). Compound 3 also suppressed neutrophil recruitment and ROS accumulation in CuSO₄-induced inflammatory zebrafish in vivo . Mechanistically, compound 3 regulated the NF-κB/JAK pathways by inhibiting phosphorylation of key proteins (IKK-α/β, IκB-α, p65, JAK1–3, TYK2) and blocking NF-κB p65 nuclear translocation. This study enriches lindenane sesquiterpenoid dimers structural diversity and identifies compound 3 as a promising lead for anti-inflammatory drug development. • Nine new lindenane sesquiterpenoid oligomers with diverse skeletons were isolated. • 3, 4 and 11 inhibited NO release more effectively than DXM (positive control). • 3 significantly inhibit neutrophil recruitment and ROS generation in vivo (zebrafish). • 3 suppresses inflammatory mediators (TNF-α, IL-6, iNOS, COX-2) and ROS generation. • 3 regulates NF-κB/JAK pathways by inhibiting phosphorylation of IκB-α, p65, JAK1–3, etc .