Planta Med 2013; 79 - PN42
DOI: 10.1055/s-0033-1348723

Determination of the Absolute Configuration of a Flavanone Isolated from a Madagascar Plant

Q Su 1, L Harinantenaina 1, PJ Brodie 1, MW Callmander 2, R Rakotondrajaona 3, E Rakotobe 3, VE Rasamison 3, DGI Kingston 1
  • 1Department of Chemistry and the Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, USA
  • 2Missouri Botanical Garden, B.P 3391, Antananarivo 101, Madagascar
  • 3Centre National d'Application des Recherches Pharmaceutiques, B.P 702, Antananarivo 101, Madagascar

As part of an International Cooperative Biodiversity Group (ICBG) program, we are focused on discovering biologically active natural products from Madagascar plants. Four antiproliferative flavanones (1-4) were isolated from an ethanol extract of the leaves of a Mundulea sp. (Fabaceae). The structures of 6,8-diprenylaromadendrin (1), lonchocarpol A (2) and mundulea-flavanone B (3) were elucidated as known compounds. Chlorospermin (4) was identified as having been previously isolated from a Glycosmis sp. (Rutaceae), but the optical rotations of the flavanone from the Glycosmis sp and from the Mundulea sp. were of opposite sign. The absolute configuration of 4 was confirmed by analysis of its Electronic Circular Dichroism (ECD) spectroscopic data. The NMR spectra and optical rotation and ECD spectroscopic data of 4 are discussed to confirm the structure and to establish the absolute stereochemistries of the two enantiomeric flavanones.