ABSTRACTA library of enriched marine natural product fractions was screened for their antiplasmodial activity using a SYBR green I fluorescence-based assay. Fractions derived from a sponge of the genusSpongosoritesexhibited potent inhibition ofPlasmodium falciparumgrowth. This genus of sponge has been reported to contain the nortopsentin and topsentin class of bis-indole imidazole alkaloids. This is the first report of nortopsentin A inhibiting parasite growth at the trophozoite stage at submicromolar 50% inhibitory concentrations (IC50).
A new approach was developed to construct quaternary stereogenic centers bearing nitrogen substituents in an enantioselective manner. The strategy takes advantage of [1,3]-chirality transfer from a chiral primary alcohol equivalent through an allyl cyanate-to-isocyanate rearrangement. This approach was employed in an efficient eight-step synthesis of the marine natural product, (+)-geranyllinaloisocyanide, in 43% overall yield.
The Bis(Indolyl)Imidazole Alkaloid Nortopsentin A Exhibits Antiplasmodial Activity
