Planta Med 2008; 74 - PC8
DOI: 10.1055/s-0028-1084526

LC-MS analysis of 13,28-epoxy-oleanane saponins in Maesa spp. extracts with antileishmanial activity

K Foubert 1, M Vermeersch 2, S Apers 1, L Pieters 1, L Maes 2
  • 1Laboratory of Pharmacognosy and Pharmaceutical Analysis, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
  • 2Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium

Saponins are natural products well known for their various biological activities. While saponins of Maesa balansae (maesabalides) displayed anti-leishmanial activity, saponins of Maesa lanceolata (maesasaponins) also showed anti-angiogenic properties [1,2]. Because of their biological interest several Maesa species from the National Botanical Garden in Meise, Belgium, and wildgrown plants from Vietnam were screened for their anti-leishmanial activity and their saponin content.

Different parts of the plants were collected, dried and extracted. Plant extracts were evaluated by LC-MS analysis and their content was compared with the maesabalides and maesasaponins. For liquid chromatography, gradient elution was used and the mass analysis was carried out with a LXQ linear ion-trap equipped with negative electrospray ionisation.

Besides the fact that several Maesa species, which were active against Leishmaniasis, contained known maesasaponins and maesabalides, the leaves of M. argentea also contained two new compounds. One component with m/z 1465 [M-H]- and RT=34.1min, and another one with m/z 1477 [M-H]- and RT=35.9min were characterised. Their MS/MS fragmentation pattern revealed a structure which was the same or closely related to respectively maesasaponin V.3 and VI.2, with one additional galactose or glucose moiety.

References: 1. Apers, S. et al. (2001) Planta Med. 67: 528–532

2. Maes, L. et al. (2004) Antimicrob. Agents Chemother. 48:130–136