An undescribed phytyl melilotic acid ester and chromomoric acid derivatives from Artemisia anomala and their cytotoxic and anti-inflammatory activities

Phytochemical investigation of the ethanol extract from Artemisia anomala twigs and leaves led to the isolation and structural elucidation of four previously unreported compounds, including a phytyl melilotic acid ester designated as artemanoin A (1), and three chromomoric acid derivatives named anomalones E − G (2–4). Their structures, including the absolute configurations, were unambiguously established through extensive spectroscopic characterization (HRESIMS, 1D/2D NMR) coupled with chemical derivatization study and quantum chemical calculations (including ECD, optical rotation and NMR computations). Notably, artemanoin A (1) represents an acyclic diterpenoid featuring an unusual ester linkage with melilotic acid, a structural motif rarely encountered in natural products. In biological evaluations, while none of the isolated compounds exhibited cytotoxic activity against the tested cancer cell lines at concentrations up to 50 μM, compounds 2–4 demonstrated significant anti-inflammatory potential, showing potent inhibition of NO production in LPS-stimulated RAW264.7 macrophages with IC₅₀ values of 2.81–4.13 μM.