Acetylcholinesterase inhibitory activity and mutagenic effects of Croton penduliflorus leaf extract constituents

Croton penduliflorus is a medicinal plant widely employed in the management of inflammatory conditions, infections and oxidative stress related diseases. The activities demonstrated by leaf extracts indicate that they possess the ability to reduce oxidative damage to cells. Repeated column fractionation of the ethyl acetate fraction of a 20% aqueous methanol leaf extract of C penduliflorus on Sephadex LH-20 afforded four phenolic compounds: quercetin-3-O-rhamnoside (1), kaempferol-3-O-rhamnoside (2), protocatechualdehyde (3A) and its solvent derived dimer (3B) along with p-hydroxybenzoic acid (4). Compound 3B is described for the first time and its significance in bioassay is briefly outlined. Structure elucidation of the isolated compounds was carried out using spectroscopic techniques. The inhibitory properties of the four compounds against acetylcholinesterase were determined using the microplate assay. The IC50 values of the isolated compounds ranged from 87.9 to 1231.9 mu M, with compound 2 having the best inhibitory activity (IC50 = 87.9 mu M). The four isolated compounds showed no mutagenic effects against Salmonella typhimurium tester strains TA98 and TA100. The moderate activity demonstrated by these compounds suggests that they could be helpful in the management of neurodegenerative disorders. (C) 2013 SAAB. Published by Elsevier B.V. All rights reserved.