Antiplasmodial activity and cytotoxicity, isolation of active alkaloids, and dereplication of Xylopia sericea leaves ethanol extract by UPLC-DAD-ESI-MS/MS.

Abstract

Objectives: To assess the antiplasmodial activity of the ethanol extract of Xylopia sericea leaves, Annonaceae, often associated with antimalarial use and to perform a bioguided isolation of active compounds.

Methods: Dereplication of ethanol extract by the UPLC-DAD-ESI-MS/MS technique allowed the identification of the major constituents, isolation and identification of alkaloids. The antiplasmodial and cytotoxic activity of the extract, fractions and isolated compounds was evaluated against the chloroquine-resistant W2 strain Plasmodium falciparum and HepG2 cells, respectively. Key findings: Ethanol extract showed high reduction of parasitemia as well as moderate cytotoxicity (86.5 3.0% growth inhibition at 50 lg/ml and CC50 72.1 5.1 lg/ml, respectively). A total of eight flavonoids were identified, and two aporphine alkaloids, anonaine and O-methylmoschatoline, were isolated. Anonaine disclosed significant antiplasmodial effect and moderate cytotoxicity (IC50 23.2 2.7 lg/ml, CC50 38.3 2.3 lg/ml, SI 1.6) while O-methylmoschatoline was not active against P. falciparum and showed a low cytotoxicity (33.5 1.9% growth inhibition at 50 lg/ml, CC50 274.4 0.5 lg/ml). Conclusions: Characterization of Xylopia sericea leaves ethanol extract by UPLCDAD-ESI-MS/MS as well as its antiplasmodial activity and the occurrence of anonaine and O-methylmoschatoline in this Xylopia species are reported by the first time.