New triterpene glycoside and other chemical constituents from the leaves of Swartzia apetala Raddi var. glabra

Abstract

A new triterpene saponin (1) was isolated from a methanol extract of Swartzia apetala Raddi var. glabra, together with the flavonoids mauritianin (2), kaempferol (3) and the triterpene saponin β-D-glucopyranosyl 3β-hydroxy-olean-12-en-28-oate (4). These compounds were characterised on the basis of their spectral data, mainly one-dimension (1D; ¹H, ¹³C, APT) and two-dimension (2D; ¹H-¹H-COSY, HMQC and HMBC) nuclear magnetic resonance (NMR) and HR-ESI-MS, and comparison with values in the literature. The analysis by HR-ESI-MS showed a mass compatible with that of triterpene saponin 1. This proposal was supported by molecular modelling. LC-HR-ESI-MS experiment was also used to evaluate the purity of 1 and allowed to speculate about the possibility of the presence of 5 in very small quantity. The extract and four compounds were assayed for antifungal activity against nine strains of Candida spp.

Keywords::

• Swartzia apetala
• triterpene saponin
• antifungal activity

Acknowledgements

The authors are grateful to CNPq, FAPERJ, INCT-INOFAR and CAPES for research fellowships and financial support.