Cholinesterase Inhibiting and Antiplasmodial Steroidal Alkaloids from Sarcococca hookeriana

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.