Flavonoid glycosides from the leaves of Allium victorialis var. platyphyllum and their anti-neuroinflammatory effects

Eight new flavonoid glycosides, named allivictoside A-H (1-8), together with twelve known flavonoids (9-20) were isolated from the leaves of Allium victorialis var. platyphyllum. The structures of 1-8 were determined by chemical and spectroscopic methods, including 1D, 2D NMR analyses and HR-MS. To evaluate the anti-neuroinflammatory activities of all isolates, we measured the secreted nitric oxide levels in murine microglia BV-2 cells stimulated by lipopolysaccharide. In this study, compounds 2, 6, 10, and 18 significantly inhibited nitric oxide production (IC50 values of 20.67, 20.42, 21.48 and 19.80 mu M, respectively) without cell toxicity. Therefore, we suggest that allivictoside B (2) and F (6), 3-O-beta-D-glucosyl-7-O-beta-D-(2-O-feruloyl) glucosylkaempferol (10) and quercetin 3-O-beta-D-glucopyranoside (18) may be considered as candidates for the treatment of diseases associated with neuroinflammation. (C) 2012 Elsevier Ltd. All rights reserved.