New sesquiterpenoids bearing 11-methyl ester group of agarwood.

Abstract Five new sesquiterpenoids (1–5), together with a known compound 6 was isolated from ethyl ether extract of agarwood. Their structures were elucidated on the basis of spectroscopic techniques (UV, IR, MS, 1D and 2D NMR), as well as by comparison with literature data. Compound 5 exhibited inhibitory activity against acetylcholinesterase with inhibition ratio of 48.33 ± 0.17% at the concentration of 50 μg/mL.