Acetyl and Butyrylcholinesterase Inhibiting Constituent from Morinda lucida Benth (Rubiaceae)

Aims: This study identified the cholinesterase inhibitory principle in Morinda lucida, one of the plants used in Nigerian ethnomedicine as memory enhancer.
Study Design: In vitro anti cholinesterase assay and spectroscopic analysis of isolated compound.
Place and Duration of Study: Department of Pharmacognosy, Obafemi Awolowo University, Nigeria between 2010 and 2012.
Methodology: Activity directed phytochemical analysis using Thin Layer Chromatography (TLC) bioautographic assay and repeated Vacuum Liquid Chromatography followed by Preparative Thin Layer Chromatography (PTLC) on silica gel was used to isolate one compound from the most active fraction of the plant.
Results: Spectroscopic analysis (H1 and 13C NMR) and comparison with literature data identified this compound as phytol (3, 7, 11, 15-tetra methyl- 2-hexadecen-1-ol), with an IC50 of 12.93 µg/ml acetyl cholinesterase (AChE) and 24.90 µg/mlbutyryl cholinesterase (BuChE).
Conclusion: Isolation of compound with cholinesterase inhibitory activity has to some extent validated the ethnomedical use of the plant as memory enhancer and has provided new information on the chemistry of the plant.