Isolation and cholinesterase activity of Amaryllidaceae alkaloids from Nerine bowdenii.

Amaryllidaceae species are known as ornamental plants. Some contain galanthamine, an acetylcholinesterase inhibitor. The chemical composition of the alkaloid extract of bulbs of Nerine bowdenii Watson has been analyzed by means of GC/MS. Twenty-two compounds were detected and nineteen of them identified, one of which was belladine. The alkaloid extract showed promising cholinesterase inhibitory activities against human blood acetylcholinesterase (HuAChE; IC50 = 87.9 +/- 3.5 microg/mL) and human plasma butyrylcholinesterase (HuBuChE; IC50 = 14.8 +/- 1.1 microg/mL). Belladine inhibited HuAChE and HuBuChE in a dose-dependent manner with IC50 values of 781 +/- 12.5 microM and 284.8 +/-4.2 microM, respectively.