Normal phase HPLC profiling of the acetylcholinesterase activity in apolar plant extracts

A Landreau; S Bertrand; C Simoes-Pires; L Marcourt; TD Bach; M Litaudon; D Guilet; P Richomme; PA Carrupt; JL Wolfender

doi:10.1055/s-0032-1321222

Normal phase HPLC profiling of the acetylcholinesterase activity in apolar plant extracts

A Landreau ¹, S Bertrand ², C Simoes-Pires ², L Marcourt ², TD Bach ¹, M Litaudon ³, D Guilet ¹, P Richomme ¹, PA Carrupt ², JL Wolfender ²

¹PRES LUNAM, Université d'Angers, Laboratoire SONAS-UFR Sciences Pharmaceutiques et Ingénierie de la Santé, Angers, France
²School of Pharmaceutical Sciences, EPGL, University of Geneva, University of Lausanne, Geneva, Switzerland
³Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles, CNRS, Gif-sur-Yvette Cedex, France

Abstract

Among nineteen evaluated Clusiaceous species, one stem bark CH₂Cl₂crude extract was selected based on a significant inhibition of acetylcholinesterase (AChE) using the micro-dilution Ellman's method [1]. A normal phase HPLC profiling with micro-fractionation of this extract provided discrete fractions every 20 seconds. In order to obtain a comprehensive profiling of AChE activity all microfractions were tested [2] in dilution assay (Ellman) as well as by bioautography (the Fast Blue B salt method). Furthermore the potency of inhibition was evaluated both by keeping the genuine concentration within the extract and after normalisation to a standard concentration level. From the active fractions five pure compounds were isolated and identified. The different methods of sample preparation and biological evaluation associated with normal-phase micro-fractionation of plant extracts are critically discussed.

[1] Brühlmann et al., Chem. Biodivers., 2004, 1, 819; [2] Wolfender et al., Chimia, 2011, 65, 400