Abstract

The saponin composition of leaves from the Medicago polymorpha cultivars 'Santiago' and 'Anglona' belonging to the botanical varieties brevispina and vulgaris, respectively, was investigated by a combination of chromatographic, spectroscopic, and spectrometric techniques. Several compounds were detected and quantitated by HPLC analysis using the external standard method. Twelve triterpene saponins (1-12) were purified by reverse-phase chromatography and their structures elucidated by spectroscopic (1D and 2D NMR, ESI-MS/MS) and chemical methods. They were identified as glycosides of echinocystic acid, hederagenin, caulophyllogenin, bayogenin, and soyasapogenol B. Two of them (2, 10) were previously reported in M. polymorpha; five of them (4, 6, 7, 9, 12) were already identified in other Medicago species; and three of them (1, 8, 11) were found in other plant genera. The two saponins identified as 3-O-alpha-L-arabinopyranosyl-28-O-[beta-D-glucopyranosyl(1 -> 6)beta-D-glucopyranoside] echinocystic acid (3) and 3-O-alpha-L-arabinopyranosyl-28-O-beta-D-glucopyranoside echinocystic acid (5) are newly identified natural compounds. The presence of echinocystic acid is reported here for the first time in the genus Medicago. Saponins from the cultivar 'Anglona' were characterized by a higher amount of echinocystic acid glycosydes, whereas saponins from the cultivar 'Santiago' were characterized by a higher amount of hederagenin glycosydes.

Autore Pugliese

• Avato Pinarosa

Tutti gli autori

• AVATO P.

Titolo volume/Rivista

Non Disponibile

Anno di pubblicazione

2011

ISSN

0021-8561

ISBN

Non Disponibile

Numero di citazioni Wos

20

Ultimo Aggiornamento Citazioni

Non Disponibile

Numero di citazioni Scopus

20

Ultimo Aggiornamento Citazioni

Non Disponibile

Settori ERC

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Codici ASJC

Non Disponibile