Undescribed sesquiterpenoids with NO production inhibitory activity from oleo-gum resin of Commiphora myrrha

Six undescribed cadinane sesquiterpenoids (1-6), two undescribed guaiane sesquiterpenoids (7-8), and an undescribed germacrane sesquiterpenoid (9) were isolated from the oleo-gum resin of Commiphora myrrha. Their structures were determined by the analysis of 1D/2D NMR and HRESIMS data, as well as quantum chemical ECD and NMR calculations. All the sesquiterpenoids were evaluated for their NO production inhibitory activity in LPS-stimulated RAW 264.7 mouse monocyte-macrophages. The results revealed that commiphone A (1) and commipholide D (7) exhibited significant inhibitory effect on NO generation with IC₅₀ values of 18.6 ± 2.0 and 37.5 ± 1.5 μM, respectively. Furthermore, 1 and 7 dose-dependently inhibited the mRNA expression of inflammatory cytokines IL-1β, IL-6 and TNF-α induced by LPS in the RAW264.7 cells, indicating that 1 and 7 possess potent anti-inflammatory activity in vitro.