Vavilosides A1/A2-B1/B2, New Furostane Glycosides From the Bulbs of Allium Vavilovii With Cytotoxic Activity Publisher Pubmed



Zolfaghari B¹ ; Sadeghi M¹ ; Troiano R² ; Lanzotti V²
Source: Bioorganic and Medicinal Chemistry Published:2013

Abstract

A phytochemical analysis of the bulbs of Allium vavilovii M. Pop. & Vved. was attained for the first time extensively, affording to the isolation of four new furostanol saponins, named vavilosides A1/A2-B1/B2 (1a/b-2a/2b), as two couple of isomers in equilibrium, together with ascalonicoside A1/A2 (3a/3b) and 22-O-methyl ascalonicoside A1/A2 (4a/4b), previously isolated from shallot, Allium ascalonicum. High concentrations of kaempferol, kaempferide, and kaempferol 4I-glucoside were also isolated. The chemical structures of the new compounds, established through a combination of extensive nuclear magnetic resonance, mass spectrometry and chemical analyses, were identified as (25R)-furost-5(6)-en-1β,3β,22α,26-tetraol 1-O-α-l- rhamnopyranosyl-(1→2)-O-β-d-galactopyranosyl 26-O-α-l- rhamnopyranoside (vaviloside A1), (25R)-furost-5(6)-en-1β,3β,22β, 26-tetraol 1-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-galactopyranosyl 26-O-α-l-rhamnopyranoside (vaviloside A2), (25R)-furost-5(6)-en-1β, 3β,22α,26-tetraol 1-O-α-l-rhamnopyranosyl-(1→2)-O-β- d-xylopyranosyl 26-O-α-l-rhamnopyranoside (vaviloside B1), (25R)-furost-5(6)-en-1β,3β,22β,26-tetraol 1-O-α-l- rhamnopyranosyl-(1→2)-O-β-d-xylopyranosyl 26-O-α-l- rhamnopyranoside (vaviloside B2). The isolated saponins showed cytotoxic activity on J-774, murine monocyte/macrophage, and WEHI-164, murine fibrosarcoma, cell lines with the following rank: vaviloside B1/B2 > ascalonicoside A1/A2 > vaviloside A1/A2. © 2013 Elsevier Ltd. All rights reserved.