LC-MS analysis of 13,28-epoxy-oleanane saponins in Maesa spp. extracts with antileishmanial activity.
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.
Foubert
Kenn
K
Laboratory of Pharmacognosy and Pharmaceutical Analysis, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, Antwerp, Belgium. kenn.foubert@ua.ac.be
Vermeersch
Marieke
M
Theunis
Mart
M
Apers
Sandra
S
Cos
Paul
P
Claeys
Magda
M
Van Puyvelde
Luc
L
Pieters
Luc
L
Maes
Louis
L
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*
D000981:Antiprotozoal Agents; D012503:Saponins