Saponins of Allium Elburzensen Publisher Pubmed



Barile E¹ ; Zolfaghari B² ; Sajjadi SE² ; Lanzotti V¹
Source: Journal of Natural Products Published:2004

Abstract

A phytochemical investigation of the bulbs of Allium elburzense has been undertaken, leading to the isolation of 13 furostanol and spirostanol saponins, eight of which are new, namely, elburzensosides A1/A2 (1a/1b), B1/B2 (2a/2b), C1/C2 (3a/3b), and D1/D2 (4a/4b). On the basis of spectroscopic analysis, mainly 2D NMR and mass spectrometry, and chemical methods, the structures of the new compounds were determined as furost-2α,3β,5α,6β,22α- pentol 3-O-β-D-glucopyranosyl 26-O-β-D-glucopyranoside (1a), furost-2α,3β,5α,6β,22α-pentol 3-O-[β-D- glucopyranosyl-(1→4)-O-β-D-glucopyranosyl]26-O-β-D- glucopyranoside (2a), furost-2α,3β,5α,22α-tetrol 3-O-β-D-glucopyranosyl 26-O-β-D-glucopyranoside (3a), and furost2α,3β,5α-22α-tetrol 3-O-[β-D-xylopyranosyl- (1→3)-O-β-D-glucopyranosyl-(1→4)-O-β-D-galactopyranosyl] 26-O-β-D-glucopyranoside (4a), and the corresponding epimers at position 22 (1b-4b). Along with these compounds we have isolated the corresponding 22-O-methyl derivatives that we consider extraction artifacts. All the new elburzensosides A1/A2-D1/D2 possess as a common structural feature an OH-5α that is rare among furostanol saponins. The reported compounds have been isolated in large amounts, and this makes A. elburzense a prolific producer of saponins of the furostanol and spirostanol types.