Synthesis and acetylcholinesterase inhibitory activities of tabersonine derivatives

Abstract

Tabersonine, the main alkaloid in Voacanga seeds, was used as a lead compound to semi-synthesize tabersonine derivatives. In total, 13 compounds, containing 10 novel tabersonine derivatives, were synthesized by introducing substituent groups R1–R5. The acetylcholinesterase (AChE) inhibitory activities of tabersnonine derivatives were evaluated using Ellman’s method. Among them, compound (7) showed the highest AChE inhibitory activity with the IC50 value was 5.32μM. The substituent groups R1–R5 showed different influences on the AChE inhibitory activities of tabersonine derivatives. The AChE inhibitory activities of tabersonine derivatives increased with the introduction of group R1 and/or combined groups R3, R4, while decreased with the introduction of group R5. And the group R2 showed no significant influence on the AChE inhibitory activities of tabersonine derivatives.