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Chemical composition of shallot (Allium ascalonicum Hort.)

Author:
Fattorusso, E., Iorizzi, M., Lanzotti, V., Taglialatela-Scafati, O.
Source:
Journal of agricultural and food chemistry 2002 v.50 no.20 pp. 5686-5690
ISSN:
0021-8561
Subject:
chemical composition, saponins, bulbs, isorhamnetin, quercetin, chemical constituents of plants, shallots, chemical structure
Abstract:
An extensive phytochemical analysis of the polar extracts from bulbs of shallot, Allium ascalonicum Hort., led to the isolation of two new furostanol saponins, named ascalonicoside A1/A2 (1a/1b) and ascalonicoside B (4), respectively, along with compounds 2a and 2b, most likely extraction artifacts. On the basis of 2D NMR and mass spectrometry data, the structures of the novel compounds were elucidated as furost-5(6)-en-3beta,22alpha-diol 1beta-O-beta-D-galactopyranosyl 26-O-[alpha-L-rhamnopyranosyl-(1 leads to 2)-O-beta-D-glucopyranoside] (1a), its epimer at position 22 (1b), and furost-5(6),20(22)-dien-3beta-ol 1beta-O-beta-D-galactopyranosyl 26-O-[alpha-L-rhamnopyranosyl-(1 leads to 2)-O-beta-D-glucopyranoside] (4). This is the first report of furostanol saponins in A. ascalonicum. High concentrations of quercetin, isorhamnetin, and their glycosides were also isolated and described.
Agid:
1363933