Saponins From Allium Minutiflorum With Antifungal Activity Publisher Pubmed



Barile E¹ ; Bonanomi G² ; Antignani V² ; Zolfaghari B³ ; Sajjadi SE³ ; Scala F² ; Lanzotti V¹
Source: Phytochemistry Published:2007

Abstract

Three saponins, named minutoside A (1), minutoside B (2), minutoside C (3), and two known sapogenins, alliogenin and neoagigenin, were isolated from the bulbs of Allium minutiflorum Regel. Elucidation of their structure was carried out by comprehensive spectroscopic analyses, including 2D NMR spectroscopy and mass spectrometry. The structures of the new compounds were identified as (25R)-furost-2α,3β,6β,22α,26-pentaol 3-O-[β-d-xylopyranosyl-(1 → 3)-O-β-d-glucopyranosyl-(1 → 4)-O-β-d-galactopyranosyl] 26-O-β-d-glucopyranoside (1), (25S)-spirostan-2α,3β,6β-triol 3-O-β-d-xylopyranosyl-(1 → 3)-O-β-d-glucopyranosyl-(1 → 4)-O-β-d-galactopyranoside (2), and (25R)-furost-2α,3β,5α,6β,22α,26-esaol 3-O-[β-d-xylopyranosyl-(1 → 3)-O-β-d-glucopyranosyl-(1 → 4)-O-β-d-galactopyranosyl] 26-O-β-d-glucopyranoside (3). The isolated compounds were evaluated for their antimicrobial activity. All the novel saponins showed a significant antifungal activity depending on their concentration and with the following rank: minutoside B > minutoside C ≫ minutoside A. No appreciable antibacterial activity was recorded. The possible role of these saponins in plant-microbe interactions is discussed. © 2006 Elsevier Ltd. All rights reserved.