Monoterpene esters and aporphine alkaloids from Illigera aromatica with inhibitory effects against cholinesterase and NO production in LPS-stimulated RAW264.7 macrophages

Three new monoterpene phenylpropionic acid esters, illigerates A-C (1-3), and one new aporphine alkaloid, illigeranine (4), as well as four known ones, actinodaphnine (5), nordicentrine (6), 8-hydroxy carvacrol (7), and 3-hydroxy-alpha,4-dimethyl styrene (8), were isolated from the tubers of Illigera aromatica. The structures of 1-4 were identified by HRESIMS, 1D and 2D NMR, and electronic circular dichroism spectra. Compound 1 potently inhibited NO production in LPS-stimulated RAW264.7 cells with an IC50 value of 18.71 +/- 0.85 mu M; compound 1, 3, and 4 showed moderate butyrylcholinesterase inhibitory activities with the IC50 values of 46.86 +/- 0.65, 53.51 +/- 0.71, and 31.62 +/- 1.15 mu M, respectively. Compound 4 showed weak AChE inhibitory activity with an IC50 value of 81.69 +/- 2.07 mu M, and compounds 5 and 6 possessed moderate AChE inhibitory activities with the IC50 values of 47.74 +/- 1.66 and 40.28 +/- 2.73 mu M, respectively. This paper provides a chemical structure and bioactive foundation for using I. aromatica as an herbal medicine.