Steroidal saponins from Asparagus africanus

Citation
A. Debella et al., Steroidal saponins from Asparagus africanus, PHYTOCHEM, 51(8), 1999, pp. 1069-1075
Citations number
14
Categorie Soggetti
Agricultural Chemistry","Animal & Plant Sciences
Journal title
PHYTOCHEMISTRY
ISSN journal
00319422 → ACNP
Volume
51
Issue
8
Year of publication
1999
Pages
1069 - 1075
Database
ISI
SICI code
0031-9422(199908)51:8<1069:SSFAA>2.0.ZU;2-8
Abstract
The structures of two new monodesmosidic spirostanosides and a new bisdesmo sidic furostanol glycoside isolated from the roots of Asparagus africanus L am. (Liliaceae) have been elucidated as (25R)-3 beta-hydroxy-5 beta-spirost an-12-one 3-O-{beta-D-glucopyranosyl-(1 --> 2)-[alpha-L-arabinopyranosyl-(1 --> 6)]-beta-D-glucopyranoside} (1), (25R)-5 beta-spirostan-3 beta-ol 3-O- {beta-D-glucopyranosyl-(1 --> 2)-[alpha-L-arabinopyranosyl-(1 --> 6)]-beta- D-glucopyranoside} (2) and 26-O-beta-D-glucopyranosyl]-22 alpha-methoxy-(25 R)-furostan-3 beta,26-diol 3-O-{beta-D-glucopyranosyl-(1 --> 2)-[beta-D-glu copyranoside} (3), respectively, by the combined use of one and two dimensi onal NMR experiments. The complete C-13 and H-1 assignments of the peracety l spirostanosides and the furostanol oligoside were derived. The interconve rsions between the methoxyl and hydroxyl group at C-22 of the furostanol gl ycoside was investigated and the genuine furostanol oligoside of A. african us appears to be the hydroxyl type based on the comparative study of the me thanol, pyridine and dioxane extracts. (C) 1999 Elsevier Science Ltd. All r ights reserved.