title: Isolation and identification of antiplasmodial N-alkylamides from Spilanthes acmella flowers using centrifugal partition chromatography and ESI-IT-TOF-MS.
abstract: The development of new antiplasmodial drugs is of primary importance due to the growing problem of multi-drug resistance of malaria parasites. Spilanthes acmella, a plant traditionally used for the treatment of toothache, was targeted as a lead for its potential antiplasmodial activity. A systematic approach for investigating a suitable centrifugal partition chromatography (CPC) solvent system for N-alkylamides separation was reported. The partition behavior of three N-alkylamides has been studied using several biphasic solvent mixtures in search of an adequate CPC solvent system for this class of compounds. Major N-alkylamides in S. acmella were isolated from a methanolic crude extract of flowers by CPC with the solvent system heptanes-ethyl acetate-methanol-water (3:2:3:2, v/v/v/v). Four N-alkylamides were purified and the structures were illustrated by electrospray ionization-ion trap-time of flight-mass spectrometry (ESI-IT-TOF-MS), ¹H nuclear magnetic resonance (¹H NMR) and ¹³C nuclear magnetic resonance (¹³C NMR). The CPC fractions, which contained natural mixtures of phytochemicals, demonstrated significantly higher antiplasmodial activity compared to corresponding purified N-alkylamides, thus suggesting that interactions between these N-alkylamides may potentiate antiplasmodial bioactivity.
authors.affiliation: Plants for Human Health Institute, North Carolina State University, North Carolina Research Campus, Kannapolis, NC 28081, USA.
authors.forename: Flaubert
authors.initials: F
authors.lastname: Mbeunkui
authors.forename: Mary H
authors.initials: MH
authors.lastname: Grace
authors.forename: Carmen
authors.initials: C
authors.lastname: Lategan
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Smith
authors.forename: Ilya
authors.initials: I
authors.lastname: Raskin
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Lila
mesh_terms: D000577:Amides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019659:Asteraceae / Q000737:chemistry*; D016466:CHO Cells; D002470:Cell Survival / Q000187:drug effects; D002498:Centrifugation; D002853:Chromatography, Liquid / Q000379:methods*; D006224:Cricetinae; D003412:Cricetulus; D035264:Flowers / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010963:Plasmodium falciparum / Q000187:drug effects; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D000577:Amides; D000962:Antimalarials