Cholinesterase inhibiting and antiplasmodial steroidal alkaloids from Sarcococca hookeriana

Abstract

Bioguided phytochemical investigation of Sarcococca hookeriana with respect to the cholinesterase enzyme inhibitory assay yielded two new pregnane-type steriodal alkaloids hookerianamide H (1) and hookerianamide I (2), along with three known alkaloids Na-methylepipachysamine D (3), sarcovagine C (4) and dictyophlebine (5). Their structures were determined with the aid of extensive spectroscopic analysis. All compounds showed good inhibitory activities against the enzymes acetylcholinesterase (IC50 2.9-34.1 μM) and butyrylcholinesterase (IC50 0.3-3.6 μM). These compounds also showed moderate antiplasmodial activity (IC50 2.4-10.3 μM) against the Plasmodium falciparum chloroquine resistant W2 strain. © 2007 Pharmaceutical Society of Japan.