title: LC-MS analysis of 13,28-epoxy-oleanane saponins in Maesa spp. extracts with antileishmanial activity.
abstract: BACKGROUND
  Saponins are natural products that are well known for a wide range of biological activities. For saponins of Maesa balansae, selective antileishmanial activity has been described.
  
  
  OBJECTIVE
  In view of their pharmacological interest, several Maesa species from the National Botanical Garden of Meise (Belgium) and wild-grown plants from Vietnam were screened for their antileishmanial potential and saponin content.
  
  
  METHODS
  Different parts of the plants (mainly leaves and twigs) were collected, dried and extracted. Plant extracts were evaluated by liquid chromatography/mass spectrometry (LC-MS) using electrospray ionisation in the negative ion mode and their saponin content was compared with those of Maesa balansae (maesabalides) and Maesa lanceolata (maesasaponins).
  
  
  RESULTS
  Several Maesa species (M. ambigua, M. argentea, M. brevipaniculata, M. japonica and M. perlarius) showed potent antileishmanial activity (<0.1 microg/mL) and indeed contained known maesasaponins and maesabalides. However the leaves of M. argentea also revealed two new compounds. Two saponins with [M - H]- ions at m/z 1465 and 1477 were characterised. Their mass spectrometric fragmentation pattern revealed a structure that was the same or closely related to maesasaponin V.3 and VI.2, respectively, but had a glycan part with one additional hexose residue.
  
  
  CONCLUSIONS
  Several known as well as new saponins from Maesa species active against leishmaniasis were characterised using LC-MS.
authors.affiliation: Laboratory of Pharmacognosy and Pharmaceutical Analysis, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, Antwerp, Belgium. kenn.foubert@ua.ac.be
authors.forename: Kenn
authors.initials: K
authors.lastname: Foubert
authors.forename: Marieke
authors.initials: M
authors.lastname: Vermeersch
authors.forename: Mart
authors.initials: M
authors.lastname: Theunis
authors.forename: Sandra
authors.initials: S
authors.lastname: Apers
authors.forename: Paul
authors.initials: P
authors.lastname: Cos
authors.forename: Magda
authors.initials: M
authors.lastname: Claeys
authors.forename: Luc
authors.initials: L
authors.lastname: Van Puyvelde
authors.forename: Luc
authors.initials: L
authors.lastname: Pieters
authors.forename: Louis
authors.initials: L
authors.lastname: Maes
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000032:analysis* / Q000494:pharmacology; D002460:Cell Line; D002853:Chromatography, Liquid / Q000379:methods*; D007891:Leishmania / Q000187:drug effects*; D029623:Primulaceae / Q000737:chemistry*; D012503:Saponins / Q000032:analysis* / Q000494:pharmacology; D013045:Species Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D000981:Antiprotozoal Agents; D012503:Saponins