Two undescribed biphenyl cyclooctene lignans with anti-inflammatory and anti-oxidant activities from the fruits of Schisandra grandiflora

Two undescribed biphenyl cyclooctene lignans, Schisandrin H (1) and Schisandrin S (2), and two known compounds (3) and (4), were extracted from fruits of Schisandra grandiflora. Structural elucidation was achieved through integrated UV, HRESIMS, NMR, ECD and ORD data analysis. At 1 μmol/L, inhibition of LPS-induced NO production in RAW264.7 macrophages was 28.85 ± 4.60% (compound 2), 8.36 ± 5.33% (3), 16.72 ± 4.42% (4) and 38.25 ± 2.54% for dexamethasone (positive control), relative to the model group. Additionally, all compounds were evaluated for in vitro anti-oxidant activity using DPPH and ABTS+ radical scavenging methods. Compounds 2 and 4 showed appreciable ABTS+ scavenging activity, with activity levels comparable to VC at higher concentrations.