Combining HPLC-PDA-MS-SPE-NMR with circular dichroism for complete natural product characterization in crude extracts: levorotatory gossypol in Thespesia danis.
J Nat Prod
; 71(4): 516-9, 2008 Apr.
Article
de En
| MEDLINE
| ID: mdl-18290629
ABSTRACT
Despite recent demonstration of the power of HPLC-PDA-MS-SPE-NMR (high-performance liquid chromatography-photodiode-array detection-mass spectrometry-solid-phase extraction-nuclear magnetic resonance) in structure determination of natural products directly from minute amounts of crude extracts, this technique leaves chirality of the compounds uncharacterized. In this work we demonstrate that postcolumn SPE is a useful method of analyte concentration and accumulation not only for NMR but also for CD (circular dichroism) spectroscopy. Thus, use of HPLC-PDA-MS-SPE-NMR in combination with CD allowed rapid detection of ( R)-(-)-gossypol [( R)- 1] in Thespesia danis, providing a very rare example of the predominance of the levorotatory enantiomer of gossypol. Enantioselectivity of the in vitro antiplasmodial activity of gossypol was also demonstrated; the IC50 value of ( R)- 1 was 4.5 +/- 0.2 microM, with the eudismic ratio of about 2.5. No gossypol was detected in Gossypioides kirkii.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Plantes médicinales
/
Spectrométrie de masse
/
Produits biologiques
/
Gossypol
/
Chromatographie en phase liquide à haute performance
/
Malvaceae
/
Antipaludiques
Limites:
Animals
Pays/Région comme sujet:
Africa
Langue:
En
Journal:
J Nat Prod
Année:
2008
Type de document:
Article
Pays d'affiliation:
Danemark