Zizaane-Type Sesquiterpenoids and Their Rearranged Derivatives from Agarwood of an <i>Aquilaria</i> Plant

Nine new sesquiterpenoids (1–9) were isolated from ethyl ether extract of agarwood originated from Aquilaria sp., including three novel sesquiterpenoids (1–3) derived from zizaane, together with six zizaane-type sesquiterpenoids (4–9). All structures were unambiguously elucidated based on 1D and 2D NMR spectra as well as by HRESIMS data. The absolute configuration of sesquiterpenoids was determined by comparison of the experimental and computed ECD spectra. In vitro anti-inflammatory assessment showed that compound 9 exhibited inhibition of NO production in LPS-stimulated RAW264.7 cells with an IC50 value of 62.22 ± 1.27 μM