Characterization of three saponins from a fraction using 1D DOSY as a solvent signal suppression tool. Agabrittonosides E–F. Furostane Saponins from Agave brittoniana Trel. spp. Brachypus |
| |
| Authors: | Francisco A. Macías José O. Guerra Ana M. Simonet Andy J. Pérez Clara Nogueiras |
| |
| Affiliation: | 1. Grupo de Alelopatía, Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Cádiz, C/República Saharaui, s/n, 11510 Puerto Real, Cádiz, Spain;2. Departamento de Licenciatura en Química, Facultad de Química y Farmacia, Universidad Central ‘Marta Abreu’ de Las Villas, Carretera a Camajuaní km 5.5, 54830 Santa Clara, Cuba;3. Departamento de Química Orgánica, Facultad de Química, Universidad de La Habana, C/Zapata s/n entre G y Carlitos Aguirre, Vedado, Plaza de la Revolución, 10400, Ciudad de La Habana, Cuba |
| |
| Abstract: | A careful NMR analysis, especially by 1D TOCSY and 1D ROESY, of a refined saponin fraction allowed us to determine the structure of three saponins from a polar extract of Agave brittoniana Trel. spp. Brachypus leaves. The use of 1D DOSY for the suppression of the solvent signal was useful to obtain the chemical shifts of anomeric signals. A full assignment of the 1H and 13C spectral data for the new saponins, agabrittonosides E–F (1–2) and the well‐known Karatavioside C (3) and their methoxyl derivatives, is reported. The structures were established using a combination of 1D and 2D (1H, 1H‐COSY, TOCSY, ROESY, g‐HSQC, g‐HMBC and g‐HSQC‐TOCSY) NMR techniques and ESI–MS. In addition, the methoxylation of these furostane saponins in the presence of MeOH was studied. Copyright © 2010 John Wiley & Sons, Ltd. |
| |
| Keywords: | NMR 1H 13C 1D DOSY solvent suppression furostane saponin characterization of fraction components Agave brittoniana |
|
|
