HPLC-DAD-SPE-NMR isolation of tetracyclic spiro-alkaloids with antiplasmodial activity from the seeds of Erythrina latissima

Abstract

Seven tetracyclic spiro-alkaloids, i.e. glucoerysodine (1), erysodine (2), epi-erythratidine (3), erysovine (4), erythratidine (5), erysotrine (6) and erythraline (7) were isolated from the seeds of Erythrina latissima by means of conventional separation methods and HPLC-DAD-SPE-NMR. Their structures were elucidated by spectroscopic means. This is the first report on the isolation of compounds 3, 5 and 6 from this plant. Antiplasmodial activity against the chloroquine-resistant strain Plasmodium falciparum K1 and cytotoxicity against MRC-5 cells (human fetal lung fibroblast cells) was assessed in vitro. Erysodine (2) and erysovine (4) showed moderate activity (IC50 6.53 µM and 4.05 µM, respectively), compared with the standard chloroquine (IC50 = 0.14 µM). No cytotoxicity was observed in a concentration up to 64.0 µM.